Page 371 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

MARGINAL PLANTS 369

Gunnera manicata Ranunculus lingua ‘Grandiflorus’ Caltha palustris
Gunnera Giant Water Buttercup Marsh Marigold

ORIGINS South America, where it grows along ORIGINS Found in temperate regions of Europe, Asia, ORIGINS Widely distributed throughout much of North
waterways in Colombia and Brazil. and North America. America, Europe, and Asia.
SIZE Stems can grow up to 6 ft (2 m) tall. SIZE Can grow up to 30 in (75 cm) tall. SIZE Can grow 12 in (30 cm) or more in height.
WATER Grow beside the pond, rather than in the water WATER Plant in the pond itself, down to 5 in (12.5 cm), WATER Plant in damp ground around the edge of the
itself. Hardy to –0°F (–18°C). or in marshy surroundings. Hardy to –20°F (–29°C). pond, or in shallow water. Hardy to –40°F (–40°C).
PROPAGATION Can be carried out by the division of PROPAGATION Easily propagated by the division of its PROPAGATION This can be achieved by the division of
existing plants. May also be grown from seed. tuberous rootstock. Can also be grown from seed. existing plants, or by growing from seed.
This is the most spectacular of all the buttercups,
thanks to its large size and the vivid yellow flowers
it produces in spring. Like other members of its
family, the Giant Water Buttercup can become
rampant if its growth is unchecked, so it should
be set in marginal containers from the outset. The
leaf shape is variable, being broader and longer on
stems that do not form flowering shoots.

With leaves up to 6 ft (2 m) wide and greenish Flowering both readily and early in the year, Marsh
flower spikes standing 3 ft (1 m) tall, this marginal Marigolds look best when planted in small groups.
needs very spacious surroundings. Gunnera, also Several cultivars now exist, including the double-
known as Giant Rhubarb, grows rapidly in a sunny bloomed ‘Flore Plena,’ which may flower again in
yet sheltered location with rich, damp soil. When early autumn, and a less vigorous Himalayan white
it dies back in winter, use the leaves to mulch the form, C. p. var. alba. The leaves of Marsh Marigolds
crown, which will help to prevent frost damage. may suffer from mildew later in the year.

Asplenium scolopendrium
Hart’s-Tongue Fern

ORIGINS This species occurs naturally in temperate parts
of Europe.
SIZE Individual fronds can be up to 16 in (40 cm) long.
WATER Grow in moist soil around the water’s edge.
Never submerge this plant. Hardy to –10°F ( –23°C).
PROPAGATION Divide plants or take leaf cuttings.
Propagates naturally through the dispersion of spores.
The attractive shape of ferns makes them a popular
choice for the surroundings of a pond, and
numerous species grow well in such locations.
Hart’s-Tongue Fern is one of the hardy ferns, ideal
for temperate areas. It has an upright growth
habit, especially in the case of new fronds, which
are pale green but become darker as they mature.
The leaves are wavy and up to 2 in (5 cm) wide.
Although ferns will not thrive if kept saturated,
they do require a relatively high level of humidity.
Plant them in a shady spot where they can draw
moisture, such as in a crack in the rockwork
around the pond, or even adjacent to a waterfall,
where they will benefit from the water spray even
in dry weather. Kept in favorable surroundings,
they will soon start to reproduce. Small offspring
may develop in tiny crevices and grow successfully
if they are not allowed to dry out. Ferns generally
prefer a shady location, out of direct sunlight.

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