There are many different species of aquatic plants, some introduce colour and decorative foliage while other are practical additions to your pond as they ensure a healthy environment is created and maintained.
This is a guide to our favourite plants and how best to grow them. Remember that a new pond filled with tap water should be left for several days before stocking with plants and planting can start any time from April through until mid-August, perhaps earlier if the weather is favourable and the water has warmed.
Decorative pond plants fall into two main categories, either marginal or deep water, there are also floating plants, and bog plants if your pond has a permanently damp marshy section. In addition, oxygenating plants are not decorative, their job is to keep the water healthy.
Marginal and deep water plants should be potted into specialist pond plant baskets which have perforated sides that allow water to penetrate. Aquatic compost, kept in place by a hessian liner and a top dressing of rounded gravel, should be always be used as the planting medium.
Occupying shallow shelves and marshy areas around the edge of the pond, with leaves and stems above the surface of the water, are plants such as the Marsh Marigold, Water-Forget-Me-Not, Iris and Primula. They can also provide a refuge for fish and each one has specific planting depth that may differ by only a few centimetres.
These occupy shallow shelves around the edge of the pond:
- Arrowhead (Saggituria saggitifolia) has petite white flowers with a violet centre that decorate sharp leaves, this native loves summer sunshine. Planting depth 5- 25cm.
- Iris Pseudacorus 'Yellow Flag' is our only native iris and has distinctive butter yellow flowers contrasting with vigorous foliage that shelters wildlife. Planting depth 0-15cm.
- Lobelia Cardinalis 'Queen Victoria' will provide a fabulous display of crimson flowers with purple tinged foliage into the autumn. Planting depth up to 15cm.
- Marsh Marigold (Caltha Palustris) Gorgeous small yellow flowers emerge from copious foliage, a native plant that flowers early in the spring. Planting depth 0-20cm.
- Water-Forget-Me-Not (Myosotis palustris) is another native, this perennial has attractive blue flowers. Tolerates shade as it floats across the pond. Planting depth 0-10cm.
Purchased in bunches with a small weight attached and having little ornamental value, oxygenating plants are the most important in the pond. They produce oxygen during daylight and also provide food and shelter for your fish, a spawning medium and a refuge for fry.
However, make sure you do not have too many, the normal stocking rate is around one bunch for every two square feet of surface water area.
Floating plants are decorative and also restrict algae growth by covering the surface and blocking sunlight. They are simply placed on the surface and will happily flourish. Probably the best example of a native species would be the Water Soldier (Stratiotes aloides) with narrow spiked leaves rising from the water's surface, it tolerates shade, has pretty white flowers, and in the winter will sink, only to re-appear in the spring.
Deep Water Plants
- Water Lily (Nymphaea), there's a fabulous range of these iconic aquatic plants and the ones we recommend include:
- 'Alba', a very popular native white lily that loves full sun. Planting depth 45-90cm.
- 'Black Princess' has lots of strikingly dark red / maroon flowers. Planting depth 30-90cm.
- 'Firecrest' features star shaped scented pink flowers with an orange centre. Planting depth 30-60cm.
- 'Pygmaea Helvola' is perfect for a small pond and has yellow cup shaped flowers with orange stamens. Planting depth 10-25cm.
- 'Sioux', a scented lily whose flowers change colour as they age from yellow to orange. Planting depth 40-90cm.
Other notable deep water plants are:
- Water Hawthorn (Aponogeton distachyos) Long leaves and scented white flowers that appear during the spring and then again in the autumn provide interest for several months. Planting depth up to 30 - 90cm.
- Water Violet (Hottonia palustris) has distinctive submerged feathery leaves and spikes of pink/purple early summer flowers, it's a fully hardy native plant. Planting depth 30cm.
- Cuckooflower (Cardamine pratensis) The early flowering 'Lady's Smock' has delicate pale lilac blooms until June on long stems.
- Purple loosestrife (Lythrum salicaria) has long spikes of nectar rich magenta flowers from June to August, loved by butterflies and bees.
- Ragged robin (Lychnis flos-cuculi) A clump forming hardy perennial, its attractive but untidy pink flowers appear on tall stems with dark green leaves.
- Snake's Head Fritillary (Fritillaria meleagris) These popular damp loving bulbs have strikingly patterned purple or mauve flowers in the spring and bluish grey foliage.
- False Goat's Beard (Astilbe) Lots of colour choices and from June to August you'll have distinctive tall fragrant feathery plumes, excellent for attracting bees and butterflies.
For further information on aquatic plants see our Guide To Creating A Wildlife Pond.