Caring for your water plants

Planting in containers

Aquatics grow well in a good topsoil with a clay base to it. Acid heath soil and chalky soil should be avoided. Manure or bonemeal should not be used because they promote the growth of algae. If slow plant growth is experienced then re-pot using fresh soil. Alternatively insert pond plant fertiliser tablets into the container.

Purpose made latticework baskets are recommended for planting up all plastic and hard base pools. Fill the container 3/4 full with soil and firm well, put the plant(s) in place and pack soil around the roots. For appearance’s sake mound up soil around the plant because once immersed in water the soil turns to mud and slumps by several centimetres. Spread 15mm of Lime-Free pea-gravel is over the top of the planted container. This gravel helps keep the soil in the basket especially where fish are likely to be nosing around making the water cloudy. 

N.B. Most aquatics, especially water lilies like a sunny warm position in the pool.

Water Lilies

1 per large 10 litre container
Place the container on the bottom of the pond. Up to 50cm depth for medium and 75cm for large varieties. If lily has no leaves on the surface after 10 days then consider raising the basket nearer to the surface. (For miniature varieties a small container is sufficient and only 20cm of water depth.)

Deep Marginals

1 or 2 per medium container of 3.5L or 5 litre
For water up to 40cms over the top of the container (see plant label or list). Aponogeton usually lose their leaves in mid-summer where water temperature exceeds 10 degrees centigrade.

Shallow Water Plants

2 per medium container of 3.5L or 5 litre or 3 per Contour 8 litre
These plants are for the ‘shelf around the side of the pond where the water may be up to 10cms over the containers. See label or list for recommended water depths.


6 leaded bunches per small container
Fill container with soil, cover with 15mm of pea-gravel. ‘Dib’ a hole and push a leaded bunch into it then gently firm around it. Complete planting quota of bunches then touch-up any gaps with gravel before lowering to pond bottom. Where the pond already has silt on the bottom the bunches can be dropped into position without container planting. 

Planting in natural and mud bottom ponds

a Hessian square can be used as a plant and soil ‘swag bag’ which is just thrown out into position. (Be sure to tie the corners together securely). Shallow water plants can be pushed into the mud by hand. If geese and ducks visit your work before the plants have rooted in then you will likely be having to repeat the process.

Floating Plants

These should be introduced last lest they get squashed by the containers!

After Planting

Be patient with your plants if they seem to be taking their time. Try not to introduce fish until three weeks after planting. Too many fish will stir up the silt and their droppings will enrich the water.* Newly planted containers of topsoil also temporarily enrich the water. Over enriched water usually goes green from the colour of a myriad of microscopic green living algae that can look like a primeval soup!. Algae are responsible for green water and green blanket weed. Oxygenators and floating plants feed off the dissolved minerals that also feed the algae. Lily leaves and floating plants provide shade which slows down the growth rate of ‘algae’. Stringy algae should be reduced with a stick twirled around in the stuff and removed from the pond.

* An initial stocking of fish of 32 cms. (including tails) per square metre of pond surface is recommended (3″ per square foot). Adult fish seem to feel secure from predators in green water and baby fish thrive on the infusoria present in green water. Excess stocking may well need a pump and pond filter to clarify the water. 

Clear Water

Be patient if your pond takes time to clear. A mature pond becomes clear when a balance is struck between available plant food and plant life. Tapwater usually contains a good feed for Pea-soup algae, so draining and refilling is not recommended except in the worst cases. Ensure that no fertilizer is washing off neighbouring garden and do not exceed recommended fish feeding (excess fishfood and fish droppings both turn the water). 

Chemical Algicides 

Some algicides have been known to kill aquatic plants. Blanketweed can be controlled with Barley Straw especially on large expanses of water.