Marginals-
Other Names ( none)
Roots submerged, leaves and flowers clearly above the surface.
Their
role is purely ornamental as they do not play a part in maintaining a
satisfactory balance in the pond. They serve two functions. The boundry between
the water and the pondside is softened which is often desirable in a Formal
pond and always essential in an informal one, and they provide floral color
and/or interesting leaves during the growing season. Many types are available.
The recommended planting depth is 0-6 in. depending on the variety- their
home is on the marginal shelf or in the shallows of the pond. The traditional
method of growing them is to plant in soil at the bottom of the shelf, but
it is better to set them in baskets. Do not mix different varieties in a
single container.
Acorus-
Sweet Flag There are two distinct
species.
Acorus
calamus
is the large one- an iris-like plant with erect sword-shaped leaves which
emit a tangerine odor when crushed. The tiny horn-like flower heads are
insignificant. The variety
'Variegatus'
is more striking- the green leaves are boldly striped with cream, and also
with rose at the start of the season. Height is 2-3 ft., planting depth 3-6
in. These two plants are highly recommended, and so is the much smaller species
(Japanese
Rush)
for small ponds and tubs. The leaves of the basic type
(A.
gramineus)
grow about 6-9 in. high, planting depth 0-1 in. They are dark and evergreen,
but there are doubts about the plant's hardiness in a severe winter. The
variety
'Variegatus'
grows to the same height- the dark green leaves are edged with pale yellow.
Propagation: Divide clumps in spring and
summer.
Alisma-
Water Plantain A
plantain-like aquatic with attractive foliage- deeply ribbed and borne on
long stalks. Throughout the summer months the tiny three-petelled flowers
appear in whorls on the upright flower-stalks. A good choice for the larger
ponds, there is one point of caution. Seeds germinate quickly and self-sown
seedlings can be a nuisance, so dead-head spent blooms.
Alisma
plantago
aquatic
is our native species with ovate leaves, pale pink flowers and flower stalks
which reach 2-3 ft. Planting depth 2-6 in.
A.
parviflora
is am American species which has round rather then ovel leaves and the flowers
are usually white rather than pink. The flower-stalks grow 1-1/2 - 2 ft.
high and the recommended planting depth is 3-5 in. The dwarf
A.
ranunculoides
(6
in.) is sometimes offered. Propagation: sow seeds or divide clumps
in summer.
Butomus-
Flowering Rush Butomus
umbellatus
is one of the most attractive aquatics and is highly recommended as a Marginal
plant for ponds everywhere. The long grass-like leaves are triangular in
section- they are purplish-green when young but this purple tinge soon
disappears. In summer the smooth and tall flower-stalks appear, reaching
2-1/2 - 4 ft. The top of each of these stalks is crowned by 20-30 rose-pink
flowers in July and August. The recommended planting depth is 3-5 in. but
it will grow reasonably well in boggy land at the edge of the pond. The creeping
rootstock produces numerous bulbils at the edges and these can be used for
propagation. It is necessary to divide the roostock every two or three years
or the number of flowering heads will decline. Propagation: Plant
bulbils or divide clumps in spring.
Calla-Bog Arum Calla
palustris
is a creeping plant with long and fleshy rhizomes which spread below the
surace and up the side of the pond. It is highly recommended for hiding the
edges of a Rigid liner pond, the camouflage being the 8 in. long glossy and
heart-shaped leaves which are abundant if the site is sunny and the water
is still. In May and June the small white flowers appear, similar in shape
but not in size to the familiar
Arum
Lily.
These blooms are pollinated by water snails and in late summer the clusters
of bright red berries appear- more showy than the flowers. The height of
C.
palustris
is 6-9 in. and the recommended planting depth is 2-4 in. Collect the berries
if you wish to raise more plants. Propagation: Sow seeds in
autumn or divide rhizomes in spring.
Caltha-
Marsh Marigold The
marsh marigolds are perhaps the most popular of all Marginal plants, and
quite rightly so. The size of the smaller types makes them suitable for small
ponds and they are reliable under a wide range of conditions. The recommended
panting depth is no problem- they need very little water above the crowns
and will grow quite happily in the bog garden. Their greatest advantage is
the time of flowering- the Buttercup-like flowers appear above the round
or heart-shaped leaves in spring. These April blooms herald in the start
of the floral year. Grow Marsh Marigolds in groups in full sun or partial
shade. The basic and most popular species is the kingcup
Caltha
palustris.
In April the bright yellow waxy green flowers are borne on branching stems
above the dark green leaves. Height 1-1/2 ft. planting depth 0-2 in. The
best Caltha of all is
C.
palustris
'Plena'-
double yellow flowers which look like small pompon Chrysanthemums appear
in April. The leafy mounds are small (6 in. - 1 ft.) and are often completely
covered by the blooms. The white variety
alba
produces
its blooms in May- height 6-9 in. planting depth 0-1 in. It is often
disappointing as a Marginal- grow it as a Bog plant.
C.
leptosepala
is a more attractive white-flowered caltha, but is not easy to find.
C.
polypetla
is a giant- height 2-3 ft. planting depth 2-5 in. The leaves and the yellow
blooms are large- not one for a small pond. Propagation: Sow
fresh seeds or divide clumps in summer.
Carex-
Sedge The
Sedges are included here as they are generally found in the Marginal plant
section of the catalogues, but these grassy perennials are generally happier
growing in wet soil rather than within the pond. Planting depth when grown
as a Marginal is 0-2 in. There is nothing special about these plants, but
the
yellow-leaved
Carex stricta 'Bowles Golden'
(1-1/2
ft.) has become quite popular in recent years.
C.
riparia
variegata
(1-2 ft.) has green and white variegated leaves.
C.
pendula
and
C.
pseudocyperus
are
the giant 3-4 ft. species which in summer bear drooping spikes of catkin-like
flowers. These tall Sedges can look attractive at the water's edge of a large
pond, but they have no place in the average-sized one. For the ordinary garden
pond there are more interesting Marginals than Carex.
Propagation:
Divide clumps in spring.
Cotula-
Golden Buttons A
useful Marginal, especially for the edge of small ponds. The spreading leafy
clumps are no more than 6 in. high and are covered all summer long with small
yellow button-like flowers. The foliage is aromatic.
Cotula
coronopifolia
is an annual and that means that it dies once the floweing season is over.
This generally does not pose a problem as the plant readily sets seed and
a flush of self-sown seedlings in spring replace last years specimens. You
can save seeds and raise pants the same way as annual bedding plants for
the garden- sow the seeds in spring and transplant into containers which
are set out on the marginal shelf in late spring. The recommended planting
depth for Cotula is 0-5 in. Propagation: Sow seeds in
spring.
Cyperus-
Umbrella Grass These
graceful members of the Sedge family are foliage plants which bear lance-shaped
leaves which radiate from the tops of the stems like the ribs of an umbrella.
The summer flower-heads are branching spikes of tiny brown or reddish flowers.
The popular one is the sweet Garlingales
Cyperus
longus
which
is used to consolidate the banks of natural ponds and is cut for flower
arranging. An invasive plant growing about 3 ft. high- planting depth 3-5
in. The dark green leaves are rough and spiky.
C.
vegetus
is more compact and therefore more suiable for the average garden pond. The
leaves are broader than those of
C.
longus
but the stems are only 1-2 ft. high. The recommended planting depth is 0-4
in- it can be grown in a bog garden. Propagation: Sow seed
or divide clumps in spring and summer.
Eriophorum-
Cotton Grass A
plant for shallow water at the edge of the pond or in the bog garden. It
is an easy one to recognize- between June and August silky cottonwool-like
seed-heads appear above the thin upright stem and the grassy foliage. Don't
bother to grow Eriophorum unless you can provide the acid soil and acid water
of its native moorland home. The popular
species Eriophorum
angustifolium
grows
1-1/2 ft. high and has a recommended planting depth of 0-2 ft. In some catalogues
you will find E. latifolium as an alternative- it is very similiar to E.
angustifolium but it has broader and less attractive leaves, and it is also
short lived. Stick with the popular one, but beware of its invasive
nature.
Propagation:
Divide clumps in spring.
Glyceria-
Water Grass Yet
another grassy Marginal, and one with a bad reputation for being invasive
and for swamping more delicate plants.
Glyceria
spectabilis
variegatus
(Manna Grass) is a striking plant growing 2-3 ft. high, with green leaves
which are boldly vegitated with yellow and white stripes. The young spring
foliage has a distinctly rosy hue. The wide-spreading grass flower-heads
are of little ornamental value and should be removed. The planting depth
is 0-6 in. and it can be grown in the bog garden. Unless Glyceria is used
to stabilise the bank of a lake or a large pond, it should always be grown
in a container to restrict its sideways spread. It is an easy plant to grow
even in partial shade and it quickly becomes established and starts to spread,
which is its problem. Propagation: Divide clumps in
spring.
Houttuynia-
houttuynia An
easy to grow carpeter for planting between taller specimens, but you must
grow it in a container to keep its invasive nature in check. The stems are
red and bluish-green leaves and they are distinctly heart-shaped. It grows
6 in.-1 ft. high and early summer the cone-shaped flowers appear, each one
surrounded by four white bracts.
Houttuynia
cordata
bears single flowers- the double-flowered variety
'Plena'
is preferred.
'Variegata'
has the most colorful foliage, redish green splashed with yellow and cream
but with few flowers. The recommended planting depth is 2-4 in. It will grow
happily at the surface or even in damp soil, but the roots are damaged in
winter if they are exposed to frost or
ice. Propagation: Divide clumps in
spring. Hypericum-
Marsh St John's Wort There
is just one species-
Hypericum
elodes.
This lowly relative of the well-known Rose of Sharon which grows in
shrub borders everywhere thrives happily in mud or an inch or two of water.
Its creeping stems and mass of small rounded and woolly leaves make it a
useful carpeter for growing between taller plants such as
Iris
or for diguising the edges of a Rigid liner pond. It spreads about 1-1/2
ft. and in July and August small yellow bowl-shaped flowers are borne at
the tips of them stems. It grows about 9 in.- 1ft. high and the recommened
planting depth is 0-2 in. Propagation: Divide clumps in spring
ortake cuttings in summer. Iris-
Iris There are three
species of Iris which can be considered to be true aquatics for growing year
round in the shallow of the pond, and it would be unthinkable to have
a collection of Marginals without at least one of them. The most important
species for the ordinary garden pond is
Iris
laevigata
(Japanese Water Iris). The three-petalled blooms are about 5 in. across and
are borne on 2 ft. high stems- the first flowers open in June and are clear
blue with a yellow line down the center of each petal. A second flush may
appear in September. There are a number of 'varieties'- choose from
'Snowdrift' (White, six petals), 'Colchesteri' (White molted
with blue, six petals), 'Dorothy' (blue with white line down the center
of each petal), 'Variegata' (blue, leaves variegated yellow and green)
and the hybrid I. 'Rose Queen' (rose-pink). The planting depth for
l. laevigata and its varieties is 0-3 in.
l.
pseudacorus
(Yellow Flag or yellow Water Iris) is more vigorous and taller than l.
laevigata- the foliage is 3-4 ft. long and the yellow flowers are in
3 ft. stems. The species is too coarse for ordinary garden ponds but the
variery 'Variegata' (2 to 2-1/2 ft) with its more restrained growth
habit and cream leaves edged with green makes an outstanding choice. Other
varieties include 'Sulphur Queen' and 'Bastardi'. The planting
depth for I. pseudacorus and its varieties is 2-10 in. The third aquatic
species is
I.
vericolor
(American Blue Flag). This is a restrained plant for the smaller pond- its
leaves are 2 ft. long and flower stalks 1-1/2 - 2 ft. high. The violet blue
flowers appear in June or July and have narrow petals blotched with gold
at the base. The popular variety is 'Kermesina'- claret-red flowers
flecked with white. The planting depth for I. versicolor and its varieties
is 2-4 in. Propagation: Divide clumps as soon as flowering
has finished.
Juncus-
Rush The Rushes appear
here because one or two varieties are listed in most books and catalogues
but they are of no special value as pond plants. The slim cylindrical leaves
and tiny flowers are generally uninteresting and various species are often
invasive. There are three which you can try.
Juncus
effusus
'Spiralis' is the Corkscrew Rush and is by far the most popular one. Height
1-1/2 ft. planting depth 3-5 in. and stems contorted in corkscrew fashion-
unusual rather then attractive.
J.
effusus
'Aureostriatus'
has green and gold variegated leaves, Height 1-1/2 ft. planting depth 2-4
in. Remove all-green leaves immediately or the plant will revert.
J.
ensifolius
is perhaps the most interesting one- the foliage is more like that of an
Iris rather than the standard Rush and in summer brown globular flower-heads
appear. Height 1-1/2 ft, planting depth 0-3 in.
Propagation: Divide clumps in spring. Lobelia-
Lobelia The
Cardinal flower (Lobelia cardinalis) will grow in the shallow water at the
pond edge or in damp soil of a Bog garden, and the experts can't agree whether
it should be treated as a Marginal or a Bog plant. It thrives in rich soil
which suggests it should be planted outside the pond, bu there it is susceptible
to slug damage and usually needs winter protection. Do plant it in the pond
if you don't have a Bog garden- the 3 ft. stems are topped by bright red
flowers in late summer early autumn. Recommended planting depth is 2-6 in.
L.
fulgens
is a larger but less hardy plant, but both giant and compact hybrids
areavailable. Look for L. Queen Victoria (5 ft. scarlet), L. 'Russian
Princess' (3 ft. pink) and L. 'Dark Crusader' (2- 1/2 ft.
dark-red). Propagation: Divide clumps in spring or take
cuttings in summer.
Mentha-
Water Mint Water
Mint (Mentha Aquatica) is a useful creeping plant which can be used to cover
the edge of the pond. It is easy to grow and spreads rapidily, which can
be a problem if you have small choice specimens growing nearby. The rule
is to grow it in a basket and trim back stems which are becoming invasive.
The rounded leaves are hairy and often take on a purplish tinge- as you would
expect, the foliage is aromatic when crushed. In mid and late summer it becomes
an attractive flower plant- the tiny lavender flowers are grouped together
in a minature powder-puffs which are borne in whorls along the stems.
These flowers are especially attractive to bees. Water mint grows 1 &
1-1/2 ft high and the recommended planting depth is 0-3 in.
Propagation:
Divide clumps in spring. Menyanthes-
Bog Bean A
sprawling plant with a creeping rootstock,
Menyanthes
trifoliata
can be used to disguise the pond edge- grow it in a container to stop it
getting out of hand. The leaves have three lobes like a Broad Bean-
hense the latin species and common names. The main feature is the display
of starry flowers which appears in May and June. They are borne in upright
spikes and are quite distinctive. The buds which are pink open into white
flowers with fringed edges to the petals. Height is about 9 in. when in flower
and thep planting depth is 1-3 in. The Bog bean is recommended in situations
where a taller plant would block the view of the water and the Water Lilies,
and also for underplanting between tall and upright
Marginals. Propagation: Divide clumps in
spring. Mimulus-
Monkey Flower There
are numorouse species, Varieties and hybrids- most of them can be grown in
either shallow water or wet soil to give a bright display of Snapdragon-like
flowers during the summer months. Unfortunately some of them such as
M.
cupreus
and
M.
cardinalis
do not survive the winter under water and so belong in the bog garden.
There is, however, a true aquatic species-
Mimulus
ringens.
The branched slender stems are about 2 ft. high, which is different from
the low-growing mound of leaves usually associated with Mimulus. Small lavender
flowers appear between June and August- planting depth 2-4 in.
M.
luteus
can be grown as a Marginal- height 9 in. planting depth 0-2 in.. Yellow flowers
with red-blotched petals appear throughout the
summer. Propagation: Sow seed or divide clumps in spring,
take cutting s in summer. Myosotis-
Water Forget-Me-Not Myosotis scorpioides
(M.
palustris) is a perennial Marginal which will creep over the edge
of the pond and root in surrounding wet soil. An untidy sprawling plant perhaps,
but highly recommended by all the experts. It grows no more than 6-9 in.
high and its free-flowering nature means that there are abundant blooms from
May until August. These flowers have a typical Forget-me-not shape- sky-blue
with yellow centers. Planting depth 0-3 in. The species is a reliable and
easy to grow plant for sun or partial shade, but there are improved
varieties. 'Mermaid' and 'Semperflorens' are claimed to be
even more free-flowering and the blooms are a little larger. For white flowers
grow variety
alba. Propagation:
Sow seed or divide clumps in spring. Myriophyllum-
Parrot's Feather The
hardy
Myriophyllum
(Water Milfoils) are used as Oxygenators in the pond. These species have
underwater leaves but there is one species that can be grown as a Marginal
plant.
Myriophyllum
proserpinacoides
(M. Aquaticum) or Parrot's Feather has sprawling pinkish stems which
float on the surface and also rise about 6 in. above the water to display
the attractive feathery foliage. The flowers are insignificant. Winter hardiness
is a problem, as the stems exposed to air are killed by frost. The plant
can be overwintered by lifting the container and keeping it indoors before
returning it to the marginal shelf in spring. That's a lot of trouble, and
it is easier to keep the crown below the ice level and let it overwinter
in the pond. Use planting depth of 4-6
in. Propagation:
Divide clumps in summer. Peltandra-
Arrow Arum The
best-known species is
Peltandra
virginica,
the Green Arrow Arum. The large arrow-shaped leaves are glossy and deeply
ribbed, and in June the flowers appear- pale green Arum-like blooms which
look rather like Callas. These flowers are followed by green berries- hense
the common name. This Peltandra grows about 1-1/2 to 2 ft. high and the
recommended planting depth is 3-5 in. You should be able to find a supplier
without much trouble- harder to find is the more showy species
P.
alba
(White Arrow Arum), The spathe of the flowers which appear in June is almost
pure white rather than green and the berries are an eye-catching red instead
dull green. The planting depth is 3-5 in.
Propagation:
Divide clumps in spring. Pontederia-
Pickerel Weed A
Marginal for which there is nothing but praise- the bold glossy leaves form
attractive clumps which do not spread to nuisance-sized proportions, and
the flowers appear when most Marginals have stopped blooming. The popular
species is
Pontederia
cordata
which
has heart-shaped leaves and between July and September it bears cylindrical
spikes of pale blue flowers. The height of the flower-stalks bearing these
terminal spikes is 2 & 2-1/2 ft. Planting depth is 3-5 in.- note that
it is important to cover the crown with at least 3 in. of water to avoid
winter frost damage. There is a white variety (alba) which is hard
to find. Equally difficult to find is the tall
P.
lanceolata
3-4ft.) which has lance-shaped leaves and bright blue flowers.
Propagation:
Divide clumps in late spring. Ranunculus-
Water Buttercup The
greater Spearwort
(Ranunculus
lingua
grandiflora)
is a tall (2-3 ft) and vigorous plant for the larger pond or lake. The pinkish
leaves appear in spring and 2 in. yellow Buttercup flowers appear all summer
long. It is widely available but the experts can't quite agree whether you
should grow this one. The plant is indeed very invasive and not right for
a tiny pond, but it can be kept in check by growing it in a container and
cutting back unwanted growth. The recommended planting depth is 2-6 in.
R.
Flammula
is
the Lessor Spearwort- much less invasive and much less showy. The 1ft. spreading
stems are useful for hiding pond edge but the pale yellow Buttercup flowers
are small and not very numorous. Planting depth 0-3 in.
Propagation:
Divide clumps in spring. Sagittaria-
Arrowhead The
common name indicates the most distinctive feature of this plant- large leaves
which are sharply and distinctly arrow-like. Three types are grown as Marginals-
the recommended planting depth is 3-5 in. and the flowering period is July
and August.
Sagittaria
japonica
produces white three-petalled flowers with yellow centers- they are borne
in whorls on 2 ft. stems. An attractive plant, but it is the double form
'Flora
Pleno'
which is most popular and most highly praised Saggittaria. The flowers are
a mass of white petals like a double Stock and the stamens are completely
hidden. A some what smaller plant is the
S.
sagittifolia
which
is more invasive than the others and its white flowers have black and dark
red centers.
Propagation:
Divide clumps in summer. Saururus-
Lizard's Tail The
only species you are likely tofind is
Saururus
cernuus,
the American Swamp Lily. The heart-shaped leaves are quite attractive but
the primary rason for growing this plant is the display of unusaul flower-heads
which appear between June and August at the top of slender stems. The small
creamy-white blooms are slightly fragrant and are clustered at the end (the
'lizard's tail'). Height is 1 & 1-1/2 ft. and the recommended planting
depth is 1-4 in. It appears in most of the catalogues but rarely in the highly
recommended list of the experts. It is an invasive aquatic, so grow it in
a container rather than soil lining the marginal shelf. There is an Asian
species
(S.
chinensis)
which is very similiar but rarely seen.
Propagation:
Divide clumps in spring. Scirpus-
Bulrush There are many speciesof
Cirpus but only two or three True Bulrush, which Is worth growing if you
want to show your friends that you do know the difference between a real
Bulrush and the incorrectly-named one
(Typha
latifolia).
This Scirpus has stiff, needle-like leaves 2-4 ft. tall and hanging tassels
of tiny brown flowers in later summer. planting depth is 2-54 in. The variegated
types are a much better choice.
S.
'Albescens'
has pale yellow Rush-like stalks (3-5 ft.) with thin vertical stripes of
green- planting depth 3-5 in. Even more popular is the Zebra Rush
S.
'Zebrinus'
with 2-3ft. high quill-like stalks which are horizontally banded in green
and white. Planting depth is 5 in. Divide every two years.
Propagation:
Divide clumps in spring. Sparganium-
Blur-reed Nearly
all of the plants in the Marginal section make a welcome addition to the
pond, although there is sometimes a precautionary note that a plant may be
too large, too invasive, or perhap too dull for the ordinary garden pond.
With this one, however, there is a definate warning. The sharp-pointed rhizomes
growing out of the container readily puncture a flexible liner. The common
one is
Sparganium
ramqsum
(S. erectus)- a Rush-like plant with 2- ft. high leaves and round
prickly seed heads. The recommended planting depth is 3-5 in. It is very
invasive, and so is the lowly
S.
minimum
with its sprawling stems and floating leaves. You will find Sparganium offered
in many catalogues. Leave it alone.
Propagation:
Divide clumps in spring. Typha-
Reedmace Typha is one of the most
widespread of all our native aquatics. The giant is the Great Reedmace
Typha
latifolia-
popular but incorrectly known as the 'Bulrush' (See Scirpus)
This familiar plant has broad leaves and 5-7 ft. stalks which in summer bear
the familiar brown 'pokers' or 'cats-tail'. Planting depth is 3-10 in. but
this is for large lakes only. Equally unsuitable for the home garden pond
is
T.
angustifolia
which has slender grey-green leaves and small pokers between June and October.
Height is 3 ft. Planting depth 1-6 in. For a small pond the only choice is
T.
minima-
1 & 1-1/2 ft. high and planting depth is 1-4 in. Rush-like foliage, squat
flower-heads. Propagation:
Divide clumps in spring. Veronica-
Brooklime A large genus of herbaceous
plants which contains just one aquatic species.
Veronica
beccabunga-
a lowly plant with untidy creeping stems and glossy olive green foliage.
It grows about 6-9 in. high and can be used to hide the pond edge- its other
virtue is the abundance of white-eyed bright blue flowers which are borne
all sumer long. The recommended planting depth is 0-4 in. The only problem
is that Brooklime starts to look weedy after a season or two. Cut back the
stems if they become too straggly and take cuttings by pushing non-flower
stem tips into the mud of the container. The plant can be left to spread
into the soil surrounding the pond as it readily roots along the length of
the stems.
Propagation:
Take cuttings in the summer. Zantedeschia-
White Arum Lily This plant is usually
regarded as a greenhouse plant and yet you will find it in various sections
of the aquatic plant catalogues, ranging from the Bog plant lists to the
Deep-water aquatics. The truth of the matter is that
zantedeschia
aethiopica
will survive the winter in most areas, provided the crown is 6 in. below
the surace. Choose the variety 'Crowborough' which is hardier than
the species. It is well worth the slight risk involved. Above the glossy
arrow-shaped leaves the 2 ft. high flower-stalks are truly eye-catching.
Around each yellow poker-shaped spadix is a large white spathe- after a few
weeks yellow berries appear.
Propagation:
Divide clumps in spring.
Water Garden & Serene Pond keeping is a journey: "We hope you
enjoy yours"!
There are two distinct
species.
Acorus
calamus
is the large one- an iris-like plant with erect sword-shaped leaves which
emit a tangerine odor when crushed. The tiny horn-like flower heads are
insignificant. The variety
'Variegatus'
is more striking- the green leaves are boldly striped with cream, and also
with rose at the start of the season. Height is 2-3 ft., planting depth 3-6
in. These two plants are highly recommended, and so is the much smaller species
(Japanese
Rush)
for small ponds and tubs. The leaves of the basic type
(A.
gramineus)
grow about 6-9 in. high, planting depth 0-1 in. They are dark and evergreen,
but there are doubts about the plant's hardiness in a severe winter. The
variety
'Variegatus'
grows to the same height- the dark green leaves are edged with pale yellow.
Propagation: Divide clumps in spring and
summer.
A
plantain-like aquatic with attractive foliage- deeply ribbed and borne on
long stalks. Throughout the summer months the tiny three-petelled flowers
appear in whorls on the upright flower-stalks. A good choice for the larger
ponds, there is one point of caution. Seeds germinate quickly and self-sown
seedlings can be a nuisance, so dead-head spent blooms.
Alisma
plantago
aquatic
is our native species with ovate leaves, pale pink flowers and flower stalks
which reach 2-3 ft. Planting depth 2-6 in.
A.
parviflora
is am American species which has round rather then ovel leaves and the flowers
are usually white rather than pink. The flower-stalks grow 1-1/2 - 2 ft.
high and the recommended planting depth is 3-5 in. The dwarf
A.
ranunculoides
(6
in.) is sometimes offered. Propagation: sow seeds or divide clumps
in summer.
Butomus
umbellatus
is one of the most attractive aquatics and is highly recommended as a Marginal
plant for ponds everywhere. The long grass-like leaves are triangular in
section- they are purplish-green when young but this purple tinge soon
disappears. In summer the smooth and tall flower-stalks appear, reaching
2-1/2 - 4 ft. The top of each of these stalks is crowned by 20-30 rose-pink
flowers in July and August. The recommended planting depth is 3-5 in. but
it will grow reasonably well in boggy land at the edge of the pond. The creeping
rootstock produces numerous bulbils at the edges and these can be used for
propagation. It is necessary to divide the roostock every two or three years
or the number of flowering heads will decline. Propagation: Plant
bulbils or divide clumps in spring.
Calla
palustris
is a creeping plant with long and fleshy rhizomes which spread below the
surace and up the side of the pond. It is highly recommended for hiding the
edges of a Rigid liner pond, the camouflage being the 8 in. long glossy and
heart-shaped leaves which are abundant if the site is sunny and the water
is still. In May and June the small white flowers appear, similar in shape
but not in size to the familiar
Arum
Lily.
These blooms are pollinated by water snails and in late summer the clusters
of bright red berries appear- more showy than the flowers. The height of
C.
palustris
is 6-9 in. and the recommended planting depth is 2-4 in. Collect the berries
if you wish to raise more plants. Propagation: Sow seeds in
autumn or divide rhizomes in spring.
The
marsh marigolds are perhaps the most popular of all Marginal plants, and
quite rightly so. The size of the smaller types makes them suitable for small
ponds and they are reliable under a wide range of conditions. The recommended
panting depth is no problem- they need very little water above the crowns
and will grow quite happily in the bog garden. Their greatest advantage is
the time of flowering- the Buttercup-like flowers appear above the round
or heart-shaped leaves in spring. These April blooms herald in the start
of the floral year. Grow Marsh Marigolds in groups in full sun or partial
shade. The basic and most popular species is the kingcup
Caltha
palustris.
In April the bright yellow waxy green flowers are borne on branching stems
above the dark green leaves. Height 1-1/2 ft. planting depth 0-2 in. The
best Caltha of all is
C.
palustris
'Plena'-
double yellow flowers which look like small pompon Chrysanthemums appear
in April. The leafy mounds are small (6 in. - 1 ft.) and are often completely
covered by the blooms. The white variety
alba
produces
its blooms in May- height 6-9 in. planting depth 0-1 in. It is often
disappointing as a Marginal- grow it as a Bog plant.
C.
leptosepala
is a more attractive white-flowered caltha, but is not easy to find.
C.
polypetla
is a giant- height 2-3 ft. planting depth 2-5 in. The leaves and the yellow
blooms are large- not one for a small pond. Propagation: Sow
fresh seeds or divide clumps in summer.
The
Sedges are included here as they are generally found in the Marginal plant
section of the catalogues, but these grassy perennials are generally happier
growing in wet soil rather than within the pond. Planting depth when grown
as a Marginal is 0-2 in. There is nothing special about these plants, but
the
yellow-leaved
Carex stricta 'Bowles Golden'
(1-1/2
ft.) has become quite popular in recent years.
C.
riparia
variegata
(1-2 ft.) has green and white variegated leaves.
C.
pendula
and
C.
pseudocyperus
are
the giant 3-4 ft. species which in summer bear drooping spikes of catkin-like
flowers. These tall Sedges can look attractive at the water's edge of a large
pond, but they have no place in the average-sized one. For the ordinary garden
pond there are more interesting Marginals than Carex.
Propagation:
Divide clumps in spring.
A
useful Marginal, especially for the edge of small ponds. The spreading leafy
clumps are no more than 6 in. high and are covered all summer long with small
yellow button-like flowers. The foliage is aromatic.
Cotula
coronopifolia
is an annual and that means that it dies once the floweing season is over.
This generally does not pose a problem as the plant readily sets seed and
a flush of self-sown seedlings in spring replace last years specimens. You
can save seeds and raise pants the same way as annual bedding plants for
the garden- sow the seeds in spring and transplant into containers which
are set out on the marginal shelf in late spring. The recommended planting
depth for Cotula is 0-5 in. Propagation: Sow seeds in
spring.
These
graceful members of the Sedge family are foliage plants which bear lance-shaped
leaves which radiate from the tops of the stems like the ribs of an umbrella.
The summer flower-heads are branching spikes of tiny brown or reddish flowers.
The popular one is the sweet Garlingales
Cyperus
longus
which
is used to consolidate the banks of natural ponds and is cut for flower
arranging. An invasive plant growing about 3 ft. high- planting depth 3-5
in. The dark green leaves are rough and spiky.
C.
vegetus
is more compact and therefore more suiable for the average garden pond. The
leaves are broader than those of
C.
longus
but the stems are only 1-2 ft. high. The recommended planting depth is 0-4
in- it can be grown in a bog garden. Propagation: Sow seed
or divide clumps in spring and summer.
A
plant for shallow water at the edge of the pond or in the bog garden. It
is an easy one to recognize- between June and August silky cottonwool-like
seed-heads appear above the thin upright stem and the grassy foliage. Don't
bother to grow Eriophorum unless you can provide the acid soil and acid water
of its native moorland home. The popular
species Eriophorum
angustifolium
grows
1-1/2 ft. high and has a recommended planting depth of 0-2 ft. In some catalogues
you will find E. latifolium as an alternative- it is very similiar to E.
angustifolium but it has broader and less attractive leaves, and it is also
short lived. Stick with the popular one, but beware of its invasive
nature.
Propagation:
Divide clumps in spring.
Yet
another grassy Marginal, and one with a bad reputation for being invasive
and for swamping more delicate plants.
Glyceria
spectabilis
variegatus
(Manna Grass) is a striking plant growing 2-3 ft. high, with green leaves
which are boldly vegitated with yellow and white stripes. The young spring
foliage has a distinctly rosy hue. The wide-spreading grass flower-heads
are of little ornamental value and should be removed. The planting depth
is 0-6 in. and it can be grown in the bog garden. Unless Glyceria is used
to stabilise the bank of a lake or a large pond, it should always be grown
in a container to restrict its sideways spread. It is an easy plant to grow
even in partial shade and it quickly becomes established and starts to spread,
which is its problem. Propagation: Divide clumps in
spring.
An
easy to grow carpeter for planting between taller specimens, but you must
grow it in a container to keep its invasive nature in check. The stems are
red and bluish-green leaves and they are distinctly heart-shaped. It grows
6 in.-1 ft. high and early summer the cone-shaped flowers appear, each one
surrounded by four white bracts.
Houttuynia
cordata
bears single flowers- the double-flowered variety
'Plena'
is preferred.
'Variegata'
has the most colorful foliage, redish green splashed with yellow and cream
but with few flowers. The recommended planting depth is 2-4 in. It will grow
happily at the surface or even in damp soil, but the roots are damaged in
winter if they are exposed to frost or
ice. Propagation: Divide clumps in
spring.
There
is just one species-
Hypericum
elodes.
This lowly relative of the well-known Rose of Sharon which grows in
shrub borders everywhere thrives happily in mud or an inch or two of water.
Its creeping stems and mass of small rounded and woolly leaves make it a
useful carpeter for growing between taller plants such as
Iris
or for diguising the edges of a Rigid liner pond. It spreads about 1-1/2
ft. and in July and August small yellow bowl-shaped flowers are borne at
the tips of them stems. It grows about 9 in.- 1ft. high and the recommened
planting depth is 0-2 in. Propagation: Divide clumps in spring
ortake cuttings in summer.
There are three
species of Iris which can be considered to be true aquatics for growing year
round in the shallow of the pond, and it would be unthinkable to have
a collection of Marginals without at least one of them. The most important
species for the ordinary garden pond is
Iris
laevigata
(Japanese Water Iris). The three-petalled blooms are about 5 in. across and
are borne on 2 ft. high stems- the first flowers open in June and are clear
blue with a yellow line down the center of each petal. A second flush may
appear in September. There are a number of 'varieties'- choose from
'Snowdrift' (White, six petals), 'Colchesteri' (White molted
with blue, six petals), 'Dorothy' (blue with white line down the center
of each petal), 'Variegata' (blue, leaves variegated yellow and green)
and the hybrid I. 'Rose Queen' (rose-pink). The planting depth for
l. laevigata and its varieties is 0-3 in.
l.
pseudacorus
(Yellow Flag or yellow Water Iris) is more vigorous and taller than l.
laevigata- the foliage is 3-4 ft. long and the yellow flowers are in
3 ft. stems. The species is too coarse for ordinary garden ponds but the
variery 'Variegata' (2 to 2-1/2 ft) with its more restrained growth
habit and cream leaves edged with green makes an outstanding choice. Other
varieties include 'Sulphur Queen' and 'Bastardi'. The planting
depth for I. pseudacorus and its varieties is 2-10 in. The third aquatic
species is
I.
vericolor
(American Blue Flag). This is a restrained plant for the smaller pond- its
leaves are 2 ft. long and flower stalks 1-1/2 - 2 ft. high. The violet blue
flowers appear in June or July and have narrow petals blotched with gold
at the base. The popular variety is 'Kermesina'- claret-red flowers
flecked with white. The planting depth for I. versicolor and its varieties
is 2-4 in. Propagation: Divide clumps as soon as flowering
has finished.
The Rushes appear
here because one or two varieties are listed in most books and catalogues
but they are of no special value as pond plants. The slim cylindrical leaves
and tiny flowers are generally uninteresting and various species are often
invasive. There are three which you can try.
Juncus
effusus
'Spiralis' is the Corkscrew Rush and is by far the most popular one. Height
1-1/2 ft. planting depth 3-5 in. and stems contorted in corkscrew fashion-
unusual rather then attractive.
J.
effusus
'Aureostriatus'
has green and gold variegated leaves, Height 1-1/2 ft. planting depth 2-4
in. Remove all-green leaves immediately or the plant will revert.
J.
ensifolius
is perhaps the most interesting one- the foliage is more like that of an
Iris rather than the standard Rush and in summer brown globular flower-heads
appear. Height 1-1/2 ft, planting depth 0-3 in.
Propagation: Divide clumps in spring.
The
Cardinal flower (Lobelia cardinalis) will grow in the shallow water at the
pond edge or in damp soil of a Bog garden, and the experts can't agree whether
it should be treated as a Marginal or a Bog plant. It thrives in rich soil
which suggests it should be planted outside the pond, bu there it is susceptible
to slug damage and usually needs winter protection. Do plant it in the pond
if you don't have a Bog garden- the 3 ft. stems are topped by bright red
flowers in late summer early autumn. Recommended planting depth is 2-6 in.
L.
fulgens
is a larger but less hardy plant, but both giant and compact hybrids
areavailable. Look for L. Queen Victoria (5 ft. scarlet), L. 'Russian
Princess' (3 ft. pink) and L. 'Dark Crusader' (2- 1/2 ft.
dark-red). Propagation: Divide clumps in spring or take
cuttings in summer.
Water
Mint (Mentha Aquatica) is a useful creeping plant which can be used to cover
the edge of the pond. It is easy to grow and spreads rapidily, which can
be a problem if you have small choice specimens growing nearby. The rule
is to grow it in a basket and trim back stems which are becoming invasive.
The rounded leaves are hairy and often take on a purplish tinge- as you would
expect, the foliage is aromatic when crushed. In mid and late summer it becomes
an attractive flower plant- the tiny lavender flowers are grouped together
in a minature powder-puffs which are borne in whorls along the stems.
These flowers are especially attractive to bees. Water mint grows 1 &
1-1/2 ft high and the recommended planting depth is 0-3 in.
Propagation:
Divide clumps in spring.
A
sprawling plant with a creeping rootstock,
Menyanthes
trifoliata
can be used to disguise the pond edge- grow it in a container to stop it
getting out of hand. The leaves have three lobes like a Broad Bean-
hense the latin species and common names. The main feature is the display
of starry flowers which appears in May and June. They are borne in upright
spikes and are quite distinctive. The buds which are pink open into white
flowers with fringed edges to the petals. Height is about 9 in. when in flower
and thep planting depth is 1-3 in. The Bog bean is recommended in situations
where a taller plant would block the view of the water and the Water Lilies,
and also for underplanting between tall and upright
Marginals. Propagation: Divide clumps in
spring.
There
are numorouse species, Varieties and hybrids- most of them can be grown in
either shallow water or wet soil to give a bright display of Snapdragon-like
flowers during the summer months. Unfortunately some of them such as
M.
cupreus
and
M.
cardinalis
do not survive the winter under water and so belong in the bog garden.
There is, however, a true aquatic species-
Mimulus
ringens.
The branched slender stems are about 2 ft. high, which is different from
the low-growing mound of leaves usually associated with Mimulus. Small lavender
flowers appear between June and August- planting depth 2-4 in.
M.
luteus
can be grown as a Marginal- height 9 in. planting depth 0-2 in.. Yellow flowers
with red-blotched petals appear throughout the
summer. Propagation: Sow seed or divide clumps in spring,
take cutting s in summer.
Myosotis scorpioides
(M.
palustris) is a perennial Marginal which will creep over the edge
of the pond and root in surrounding wet soil. An untidy sprawling plant perhaps,
but highly recommended by all the experts. It grows no more than 6-9 in.
high and its free-flowering nature means that there are abundant blooms from
May until August. These flowers have a typical Forget-me-not shape- sky-blue
with yellow centers. Planting depth 0-3 in. The species is a reliable and
easy to grow plant for sun or partial shade, but there are improved
varieties. 'Mermaid' and 'Semperflorens' are claimed to be
even more free-flowering and the blooms are a little larger. For white flowers
grow variety
alba. Propagation:
Sow seed or divide clumps in spring.
The
hardy
Myriophyllum
(Water Milfoils) are used as Oxygenators in the pond. These species have
underwater leaves but there is one species that can be grown as a Marginal
plant.
Myriophyllum
proserpinacoides
(M. Aquaticum) or Parrot's Feather has sprawling pinkish stems which
float on the surface and also rise about 6 in. above the water to display
the attractive feathery foliage. The flowers are insignificant. Winter hardiness
is a problem, as the stems exposed to air are killed by frost. The plant
can be overwintered by lifting the container and keeping it indoors before
returning it to the marginal shelf in spring. That's a lot of trouble, and
it is easier to keep the crown below the ice level and let it overwinter
in the pond. Use planting depth of 4-6
in. Propagation:
Divide clumps in summer.
The
best-known species is
Peltandra
virginica,
the Green Arrow Arum. The large arrow-shaped leaves are glossy and deeply
ribbed, and in June the flowers appear- pale green Arum-like blooms which
look rather like Callas. These flowers are followed by green berries- hense
the common name. This Peltandra grows about 1-1/2 to 2 ft. high and the
recommended planting depth is 3-5 in. You should be able to find a supplier
without much trouble- harder to find is the more showy species
P.
alba
(White Arrow Arum), The spathe of the flowers which appear in June is almost
pure white rather than green and the berries are an eye-catching red instead
dull green. The planting depth is 3-5 in.
Propagation:
Divide clumps in spring.
A
Marginal for which there is nothing but praise- the bold glossy leaves form
attractive clumps which do not spread to nuisance-sized proportions, and
the flowers appear when most Marginals have stopped blooming. The popular
species is
Pontederia
cordata
which
has heart-shaped leaves and between July and September it bears cylindrical
spikes of pale blue flowers. The height of the flower-stalks bearing these
terminal spikes is 2 & 2-1/2 ft. Planting depth is 3-5 in.- note that
it is important to cover the crown with at least 3 in. of water to avoid
winter frost damage. There is a white variety (alba) which is hard
to find. Equally difficult to find is the tall
P.
lanceolata
3-4ft.) which has lance-shaped leaves and bright blue flowers.
Propagation:
Divide clumps in late spring.
The
greater Spearwort
(Ranunculus
lingua
grandiflora)
is a tall (2-3 ft) and vigorous plant for the larger pond or lake. The pinkish
leaves appear in spring and 2 in. yellow Buttercup flowers appear all summer
long. It is widely available but the experts can't quite agree whether you
should grow this one. The plant is indeed very invasive and not right for
a tiny pond, but it can be kept in check by growing it in a container and
cutting back unwanted growth. The recommended planting depth is 2-6 in.
R.
Flammula
is
the Lessor Spearwort- much less invasive and much less showy. The 1ft. spreading
stems are useful for hiding pond edge but the pale yellow Buttercup flowers
are small and not very numorous. Planting depth 0-3 in.
Propagation:
Divide clumps in spring.
The
common name indicates the most distinctive feature of this plant- large leaves
which are sharply and distinctly arrow-like. Three types are grown as Marginals-
the recommended planting depth is 3-5 in. and the flowering period is July
and August.
Sagittaria
japonica
produces white three-petalled flowers with yellow centers- they are borne
in whorls on 2 ft. stems. An attractive plant, but it is the double form
'Flora
Pleno'
which is most popular and most highly praised Saggittaria. The flowers are
a mass of white petals like a double Stock and the stamens are completely
hidden. A some what smaller plant is the
S.
sagittifolia
which
is more invasive than the others and its white flowers have black and dark
red centers.
Propagation:
Divide clumps in summer.
The
only species you are likely tofind is
Saururus
cernuus,
the American Swamp Lily. The heart-shaped leaves are quite attractive but
the primary rason for growing this plant is the display of unusaul flower-heads
which appear between June and August at the top of slender stems. The small
creamy-white blooms are slightly fragrant and are clustered at the end (the
'lizard's tail'). Height is 1 & 1-1/2 ft. and the recommended planting
depth is 1-4 in. It appears in most of the catalogues but rarely in the highly
recommended list of the experts. It is an invasive aquatic, so grow it in
a container rather than soil lining the marginal shelf. There is an Asian
species
(S.
chinensis)
which is very similiar but rarely seen.
Propagation:
Divide clumps in spring.
There are many speciesof
Cirpus but only two or three True Bulrush, which Is worth growing if you
want to show your friends that you do know the difference between a real
Bulrush and the incorrectly-named one
(Typha
latifolia).
This Scirpus has stiff, needle-like leaves 2-4 ft. tall and hanging tassels
of tiny brown flowers in later summer. planting depth is 2-54 in. The variegated
types are a much better choice.
S.
'Albescens'
has pale yellow Rush-like stalks (3-5 ft.) with thin vertical stripes of
green- planting depth 3-5 in. Even more popular is the Zebra Rush
S.
'Zebrinus'
with 2-3ft. high quill-like stalks which are horizontally banded in green
and white. Planting depth is 5 in. Divide every two years.
Propagation:
Divide clumps in spring.
Nearly
all of the plants in the Marginal section make a welcome addition to the
pond, although there is sometimes a precautionary note that a plant may be
too large, too invasive, or perhap too dull for the ordinary garden pond.
With this one, however, there is a definate warning. The sharp-pointed rhizomes
growing out of the container readily puncture a flexible liner. The common
one is
Sparganium
ramqsum
(S. erectus)- a Rush-like plant with 2- ft. high leaves and round
prickly seed heads. The recommended planting depth is 3-5 in. It is very
invasive, and so is the lowly
S.
minimum
with its sprawling stems and floating leaves. You will find Sparganium offered
in many catalogues. Leave it alone.
Propagation:
Divide clumps in spring.
Typha is one of the most
widespread of all our native aquatics. The giant is the Great Reedmace
Typha
latifolia-
popular but incorrectly known as the 'Bulrush' (See Scirpus)
This familiar plant has broad leaves and 5-7 ft. stalks which in summer bear
the familiar brown 'pokers' or 'cats-tail'. Planting depth is 3-10 in. but
this is for large lakes only. Equally unsuitable for the home garden pond
is
T.
angustifolia
which has slender grey-green leaves and small pokers between June and October.
Height is 3 ft. Planting depth 1-6 in. For a small pond the only choice is
T.
minima-
1 & 1-1/2 ft. high and planting depth is 1-4 in. Rush-like foliage, squat
flower-heads. Propagation:
Divide clumps in spring.
A large genus of herbaceous
plants which contains just one aquatic species.
Veronica
beccabunga-
a lowly plant with untidy creeping stems and glossy olive green foliage.
It grows about 6-9 in. high and can be used to hide the pond edge- its other
virtue is the abundance of white-eyed bright blue flowers which are borne
all sumer long. The recommended planting depth is 0-4 in. The only problem
is that Brooklime starts to look weedy after a season or two. Cut back the
stems if they become too straggly and take cuttings by pushing non-flower
stem tips into the mud of the container. The plant can be left to spread
into the soil surrounding the pond as it readily roots along the length of
the stems.
Propagation:
Take cuttings in the summer.
This plant is usually
regarded as a greenhouse plant and yet you will find it in various sections
of the aquatic plant catalogues, ranging from the Bog plant lists to the
Deep-water aquatics. The truth of the matter is that
zantedeschia
aethiopica
will survive the winter in most areas, provided the crown is 6 in. below
the surace. Choose the variety 'Crowborough' which is hardier than
the species. It is well worth the slight risk involved. Above the glossy
arrow-shaped leaves the 2 ft. high flower-stalks are truly eye-catching.
Around each yellow poker-shaped spadix is a large white spathe- after a few
weeks yellow berries appear.
Propagation:
Divide clumps in spring.