Planting Water Garden Plants

Fortunately, the planting season for aquatics coincides with the active growing period, which makes handling the plants much easier than if they were dormant. In addition, you can see the prospects for growth. Plants should also be lifted and divided at the same time, there being a clear indication of what will be good and what should be discarded.

 

USING CONTAINERS

The use of planting containers is essential in the modern domestic garden pool. Without containing the plants in some way, the whole thing can rapidly get out of hand. Even the most desirable of aquatics, the waterlilies, will overwhelm everything else when planted in an earth-bottomed pond. It is true that containers produce some constraint upon growth, but if the plants are fed and maintained properly, any potentially adverse effects will be minimized.

A wide range of containers has been used for planting aquatics in the past. Before the advent of plastic planting baskets, plants were grown in wooden crates and wicker baskets, although in larger pools specially built planting pits were prepared. Today, the plastic planting basket, in its many different shapes and with micro-mesh holes, is the most popular container for aquatics. Like its predecessors, it is more expensive than a conventional plant pot, and the question posed by many newcomers to water gardening is why aquatics must be grown in this type of container, rather than a normal pot.

In fact, some aquatic plants will grow tolerably well in pots for some time. A number of submerged plants, which use their roots mainly for anchorage and derive nourishment through the foliage, will be perfectly happy under such conditions. Some vigorous marginal plants also grow well in pots, but because of their height and the tapered shape of the pots, become unstable and will regularly tumble into the water. There is little more unsavoury than a reed or rush that has spent half its life being blown over into the pond by the wind, then reinstated having gained a coating of filamentous algae. Pots are not stable when growing emergent aquatics, which is why planting baskets are designed with wide bases.

For most aquatics, especially waterlilies and other deep-water subjects, an open latticework container is vital. They require freedom for gaseous exchange, which is restricted by a solid pot. The latter leads to offensive conditions within the compost, which becomes blue-black in colour, anaerobic and foul smelling. This causes the roots to begin to die, and the plant rapidly diminishes in size. While waterlilies suffer the worst effects from closed containers, the majority of other plants also suffer to some degree from this type of constraint.

 

PLANTING TECHNIQUE

Planting aquatics is very simple, provided you follow a few simple rules. Each container should be lined with a square of hessian to prevent any soil from escaping into the water, although this is said to be unnecessary with modern micro-mesh baskets. Loosely fill the container to the top with soil or compost, then plant the aquatic.

Using a watering can with a fine rose, thoroughly soak the container. This will drive out all the air and the compost will sink. Add further compost and water again until it has settled solidly, about 1cm (3/8in) below the rim of the basket. Then add a layer of pea gravel and water thoroughly once more. This will ensure that the plant remains securely planted when the container is eventually placed in the pool. The gravel will help to prevent soil from escaping from the top of the container and, in the longer term, stop fish from stirring up the compost and clouding the water. Aquatic planting baskets become the home for all manner of aquatic insect life and their larvae, which are a valuable source of food for fish. The latter will delve into the compost in search of such delicacies, but if they have to probe through the pea gravel, they are less likely to cloud the water.

At the beginning of the planting season, aquatics can be planted almost in the condition in which they are received from the nursery; later on, they will require cutting back. Do not he frightened to remove the foliage from any rooted aquatic plant. Provided the crown is sound, it will grow away quickly. Of all garden plants, the aquatics arc among the most rapid growers.

Waterlilies that have excess foliage when planted, especially if bare-rooted, will rarely remain planted securely. The floating foliage acts as a buoyancy aid, lifting the plant out of the basket. This is a common occurrence when attempts are made to stand waterlilies on heaps of bricks so that they are at the same depth as in their previous home and their existing foliage floats on the surface. Doing so is a waste of time. Cut the leaves back to the crown, plant properly and place the waterlily on the floor of the pool in its permanent position. The fresh foliage will reach the top in a matter of days and will not linger, looking sickly and yellow, as it does when plants are moved and their leaves preserved.

Do not be concerned about cutting back very tall marginals in the same way. Often, by mid-season, a new marginal subject will have grown completely out of proportion with its surroundings. Shortening the foliage will encourage rapid rooting and speedy regrowth. It will merely look a little less pleasing than a plant established in early spring and allowed to grow away freely. Bunched submerged plants should be planted exactly as they are received, with the lead intact. Plant so that the weight is covered completely by compost. If it is left exposed, the stems will rot through at that point and the tops will break away. Then the plants will need re-bunching and re-establishing.

 

PLANTING IN CONTAINERS

1 Although said to be unnecessary with the newer micromesh aquatic planting baskets, it is probably best to line all planting containers with hessian to prevent soil spillage into the pool.

2 Fill the planting basket with a good clean heavy soil or an aquatic planting compost. Using a watering can fitted with a fine rose, thoroughly soak the soil to drive out the air before planting.

3 Press the plant firmly into the compost, water again and then cover the surface of the compost with a layer of fine pea gravel. This will prevent the fish from disturbing the soil.