Pond Plants and Ecosystem: Tips for Marginal, Oxygenating, Water Lilies


Pond Series - Part 3

(Part 3)

Discover more about pond creation by reading Part 1: Garden Pond Design & Planning Guide and Part 2: Pond Construction Guide.

The Beauty of Ponds and their Plants


Planting around and in a pond or water feature not only adds beauty but also provides a vital haven for wildlife. The plants themselves contribute to maintaining the ecosystem by absorbing excess nutrients that could damage water quality and its inhabitants.

Planting Around and in Your Pond

Let’s start with the basics. Once the water feature has been constructed, it is ready for planting. If you’ve gone for a wildlife pond, it should have several layers in it to create suitable habitats for different species.

Planting Pond Plants that create a suitable habitat for different species
Gardens by Keltie & Clark

Understanding Bog, Marsh, and Marginal Plants

Is there a difference between bog, marsh and marginal plants?

Yes, there is. Bog or marsh plants have similar requirements—they prefer their roots in moist soil but not submerged. Marginal plants, as the name suggests, thrive on the edges of waterways, lakes, and ponds. They are adapted to tidal flows and seasonal fluctuations in water depth. They develop longer roots to hold firm and seek nutrients during dry spells when water levels drop.

Planting depths for bog/marsh plants such as Astilbe, Hosta, or Rodgersia should be at the water’s edge. Here, the soil is damp, but their stems don’t get submerged. Marginal plants like Flowering Rush (Butomus umbellatus), Iris, or Purple Loosestrife (Lythrum salicaria) can tolerate varying depths from 0 to 15cm underwater. Plant these on shelves or sloping pond edges for a natural look.

butomus umbellatus
Butomus umbellatus
purple iris
Purple marginal iris
Rodgersia bronze
Rodgersia bronze

Oxygenators and Deeper Planting

Oxygenators, help maintain the pond ecosystem by photosynthesising oxygen, regulating water quality. Submerged oxygenating plants absorb excess nutrients, suppress algae growth, and keep the water clear. These plants can be anchored underwater in bunches or floated as rafts for aquatic insects and dragonflies. Generally, 3 to 8 plants per cubic metre should suffice.

Water lilies add beauty to a pond and provide shade and resting platforms for wildlife. Planting depths vary with size: small water lilies should be submerged 30-60cm, medium ones 30-90cm, and larger cultivars 30-150cm deep.

DP green dragonfly reflection water plant      frog and water lily

Essential Pond Maintenance and Problem Solving

Proper pond maintenance is crucial and should be done at least twice a year, in spring and autumn. Good pond hygiene involves removing plant material before it rots and affects water quality. Regularly check and clear pumps and filters of debris.

If you have fish, select high-quality fish feed to prevent algae growth. Proper feeding reduces waste and maintains water quality.

For algae problems like blanket weed (Spirogyra), barley straw is a natural solution. Use 20-50 grams of straw per square metre of pond. It works best in water temperatures above 10 degrees, becoming more effective as temperatures reach 15-20 degrees. Applications last up to 6 months and do not inhibit the growth of other aquatic plants or animals.

Golden pond   Enjoy Your Pond!

Sit back and enjoy the beauty and tranquillity of your well-maintained pond!

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