Plants for Mini-Pools
You will need plants to aerate your pool and also some to decorate it. If possible, install plants around the pool as well as in it; this will help to ‘soften’ the edges and give it a well-established look in a very short time.
A pond up to 1.5 square metres (16 sq ft) in size needs to have at least five oxygenating plants in it to keep the water sweet and clean. Permanently submerged plants such as Elodea and Myriophyllum will do this job efficiently, as will water starwort (Callitriche stagnalis), which also keeps algae at bay. It needs planting in heavy soil at the bottom of the pool, where it spreads to form a mat.
Apart from the familiar and well-loved water(Nymphaea), there are a number of flowers for small ponds: two of the best are the water-violet or featherfoil (Hoitonia palustris) and the water-soldier (Stratiotes abides), which looks just like the spider plant, sending out runners with mini-plants on the end. The normally floats just under the surface of the water but comes up to bloom, when it produces white flowers in June.
Marginal plants to fringe your pond come into two categories: those that need some depth of water – about 150-450mm (6-18in) – to the shallow marginals which just want to paddle in the water to a depth of 100mm (4in) at the most. The water hawthorn (Aponogeton distachyus), with its starry white flowers, cotton grass with its attractive tufts, and marsh( ), with its round, golden flowerheads, are all good choices.