Choosing Water Garden Plants for Your Water Garden Design
Once your pond or water garden design is filled and you are sure it is clean, you will need to furnish it with suitable water garden plants of the aquatic type. The lovely water lily is probably the most popular. Nurserymen stock a wonderful range of these plants, which are not reallyincidentally, but nymphea and are related to the lotus. But first just a word about aquatics generally. Almost all are perennials and as you would expect they are hardy, half-hardy and tender. The latter are best for indoor aquaria or greenhouse pools. The first can be grown outdoors all the year through, though some disappear or almost so in winter; the second need to be protected from frost.
Most aquatic plants can be established from spring until early autumn. If you can, use rain water rather than tap. In any case, allow the water to stand in the pool for a few days to become acclimatized before you plant. Half-fill the pond so that the plants can be lowered in and then gradually fill the water garden design. Your choice of plants will depend upon the depth of water.
Water garden plants are as varied as all other plants are. You can have tall graceful ones, like the acorus or the variegated sweet flag, as well as the airy-fairy ones, such as the water saxifrage. You can have scented ones, such as preslia and you can have various colours. (And even if you don’t want to go to the trouble of making a water garden design but would like some water garden plants, you can grow certain kinds in an old barrel cut in half and sunk in the ground or in a winecrock or sink).
Aquatic plants are usually classified by the depth of water they need. Submerged aquatics with’ leaves that float on the surface usually need 12 to 18 ins. over them. Others that need their roots only submerged will grow up out of the water. Some need only 3 to 5 ins. or even just mud. And others are so easy that they will grow in any depth of water from 3 to 18 ins, their leaves andstanding above the water level. Others are merely tossed in and will float.
If you want to decorate the fringes of your water garden design, you will need marginal plants. There are two types catalogued. Some belong to the group of aquatics proper already mentioned. They need deep water from 6 to 18 inches, and will grow from the bottom of the pool and rise well above the surface. The real marginal plants grow right on the edge, some with their toes just touching the water and others paddling in four inches of it. These are usually grown on a shelf round the pond, made especially for this purpose. If no shelf exists, they should be in shallow planting crates stood, to raise them, on bricks or stones.
The submerged oxygenating aquatics will give a depth and air of mystery to your pond as well as providing delightful places forto swim in and shade and protection for their young who, if they have no places of escape, get eaten by their elders. Most of these plants appear as no more than green shapes below the water, some are flowering and decorative.
There are floating aquatics many of which are native plants, with delightful names such as fairy moss, water fan, floating water hyacinth, frogbit, a charming plant with small snow white flowers very closely resembling water lilies; water lettuce, duck weed, crystalwort, water soldier, a curious plant with spiny foliage like a pineapple. This plant will lie submerged for a long time and then in the summer come to the surface to produce flowers; water chestnut is a rare and beautiful floating plant which has thin stems at the end of which there are large rosettes of deep green foliage and pure white flowers.
And when you have planted your garden pond and its margins, there are still many lovely perennials that can be grown by the waterside and which will give distinction to your garden. All they need is moist. Some will grow in semi-shade. They include several iris, the lovely day-lilies, primulas, lythrum and the tall showy lobelias.
Many people think that because so many of the water garden plants need to grow from the bottom, the obvious thing to do is place a layer of soil on the base and plant them in this. This is quite good if you have an enormous water garden design, but hopeless for a little water garden. Once they are allowed to roam as they wish, the strong growing plants will dominate the others and you, will have a bad job in thinning them out. Instead grow the submerged plants in pots, baskets or crates. If you have an old wicker basket no longer serviceable, you can use this to grow your water lilies in. In my own water garden, I have used plastic planting crates and perforated pots. Wire mesh containers can also be used. You have to make these yourself. Alternatively, if you make a concrete pond you can build planting pockets.
The soil for water garden plants must be very heavy. Well-rotted cow manure is most beneficial, so try to mix some with your soil, half and half. If you can’t get cow manure, use a slow-acting manure such as bonemeal. You will need roughly a tablespoonful to a bucketful. Put this enriched soil in the lower half of the crate, ordinary soil above.
If you make wire netting crates yourself, line these with fibrous turf so that the loam does not escape. This is grass you have stripped off from parts of the garden and allowed to rot away, but not to disintegrate. Fill the crates with this, plant and lower them into the pond.
Water lilies come in many beautiful colours as well as white. One of the prettiest of the whites is delicately scentedodorata alba which flowers from June to October. As well as white you can have rose-pink and salmon hues, deep wine, crimson and red; and copper, orange and yellow. There are certain miniature types which will grow in as little as 3 inches of water. But most water lilies require from 6-18 ins. of water. If you want fish, then you need at least 1 ins. of water in the deepest part of the pond. You must also take into consideration the depth of soil in which the lilies are planted and measure the depth of water above the soil surface. Water lilies must be in full sun. It is best to fill the pond slowly as the stems grow, so that the leaves are continually supported on the surface of the water. The alternative is to stand pots or crates on bricks, so that the first leaves float on the surface and to remove the bricks as the plants grow, but this is difficult I think.
Nuphars are other lovely aquatics whose underwater leaves look like translucent hart’s tongue ferns but whose surface leaves look like water lily “pads”. N. lutes, is a pretty species for a pool. The lovely fragrant water hawthorn, aponogeton, will grow in a tub, pool or lake. In mild winters it will bloom until after Christmas! All these are for the centre of the pool.
The aim in every water garden design pool, should be to have a good balance of plants and fish. Any supplier will advise on the number and types of plants and fish required for a specific water garden design pool. Without this proper balance, the water is certain to turn green and murky in the spring and early summer. Even with this balance, it is probable that a certain amount of algae will discolour the water in spring. This is nothing to worry about. The water will clear in a short while if it contains the correct balance of life.
When the water garden pool becomes frozen over in winter, gases caused by decaying vegetation cannot escape easily. If an accumulation of leaves lies at the bottom of the pool, harmful gases are given off in great quantities. Cold itself does little harm to fish, but lack of fresh air andkill them. So keep a part of the ice open on a frozen pond to maintain a supply of fresh air. Never break thick ice by banging it, for this causes something like an explosion which can kill fish. A rubber ball floating on the surface which you can move daily is one method of keeping an air-hole open.
People who have an electrically operated fountain or pump which is little used in winter could disconnect it and use the supply to operate an easily connected 1oo watt pool heater instead. This should. Be switched on in severe weather only to keep a little area free from ice.