Although they have a tendency to get a little over-looked at times, floating plants can have an important role to play in your pond, providing useful surface cover where the leaves of water lilies and the like do not reach, and making a unique contribution to the overall visual impact.
Some of these plants – the likes of the Duckweeds, for instance – form carpets of small leaves, while others, such as Water Soldier, do not, but in all cases, planting could hardly be any simpler, just bring them home and drop them in.
A number of different varieties are routinely offered, usually from late spring through to early autumn – but not all kinds are as well suited as others to the garden pond or the rigours of the British climate. Some, like the striking Water Lettuce (Pistia stratoites) for example, are difficult to nurture in anything but the best of summers, while others are just too invasive. It’s also important to be aware that many will not tolerate frost, so you may either have to replace them on a yearly basis, or make alternative arrangements for their care when the weather begins to turn colder.
While personal preference and the type of pond you have obviously has a big influence on the eventual choice, here are four floaters that you might like to consider.
Fairy Moss (Azolla caroliniana)
Probably the most familiar of all the floating plants Azolla is a miniature fern – hence its alternative common name of “mosquito fern” – with fronds that are little more than half-an-inch across. Left to its own devices, however, it will multiply rapidly and can soon spread across the water’s surface, so you’ll need to exercise a bit of care with it if access to the pond edge is restricted, or it may soon get out of control. Despite its tendency to take over, its delicate, pale green foliage – turning red as summer progresses – makes it an attractive addition to the pond.
The arrival of frost tends to kill much of it off, so over winter a small amount in a jar of pond water until the following April or May.
Ivy-leaved Duckweed (Lemna trisulca)
Duckweeds are well-known floating plants, with their small clover-shaped leaves and roots that dangle down into the water. Different varieties are to be found naturally in almost any pond, ditch or slow moving stream, but since this kind is the least invasive of its family it is widely viewed as the only one that is really suitable for most garden ponds. It is a good food source for many kinds of fish and provides excellent shade for the water.
A number of other duckweeds are commonly offered for sale, particularly Lesser and Greater Duckweeds (L. minor and L. polyrhiza), but they are generally best avoided since they multiply and grow at such a prodigious rate.
Water Hyacinth (Eichornia crassipes)
A major invasive plague of the waterways in warmer climes, Water Hyacinths are large, fleshy plants with spectacular blue, yellow or cream flowers forming a foot (30cm) or so above the surface – although they are only produced in good summers.
As you might expect from a plant more at home in the Everglades than Evesham, Eichornia is far from frost-hardy, so you’ll need to take any you want to over-winter indoors before the nights get too cold, or buy some more next year.
Water Soldier (Stratiotes aloides)
Despite its exotic appearance – it looks for all the world like a floating pineapple top – the Water Soldier is a UK native, making it ideal for anyone wanting a spot of low-maintenance impact in their pond. Once their flowering season is over and winter approaches, the plants sink to the bottom of the pond where they will remain dormant until the following summer, when they float back up to the surface to bloom again.
Although under ideal conditions Stratiotes can multiply quickly and so might become a problem, it very rarely seems to cause much trouble, which probably explains why these attractively shaped plants are such firm favourites with pond keepers.
Whether you pick your floating plants for their colour, shape or flowers – or simply to provide a bit of shade in the water – there’s plenty of choice available, so between native species and their exotic kin, with careful selection you’re bound to find something to suit.
Other types of pond plants include: Oxygenating pond plants, marginal pond plants, pond edge plants, floating pond plants, floating pond water lilies and deep water pond plants.