Adding life to your pond
Most pond plants are easy to grow and require little maintenance other than the occasional tidy up to remove tired-looking foliage or fading flowerheads, but for a pond to be relatively easy to look after you have to choose varieties that suit the size of the pond and the depth of the water. You also need to bear in mind how the plants will combine if you want to achieve an attractive looking water feature for most of the year.
If you have a pond with a surface area of around 5m² and you choose the right combination of plants, the pond can be virtually self-sustaining. Aim to cover at least one-third of the surface area with floating plants to cut down the amount of sunlight penetrating the water. Floating leaves, such as waterlily pads, not only provide shade and hiding places for young fish, but also prevent the growth of algae that can turn the water a murky shade of green
Submerged plants are also an essential ingredient of an easy-care pond. They help oxygenate the water and absorb any excess of nutrients on which green algae would otherwise feed. Aim to add about 10 submerged plants per square metre of surface area. Plants which grow in the shallow water at the edge of a pond are known as marginal aquatics. Most will spread out to cover an area of 30-50cm (12-20in) so they eventually need to be spaced at this distance along the shelf. However, to create instantly attractive planting, group plants closer together and use containers filled with flowers and foliage around the pond to help soften the edges.
Provided you grow your aquatic plants in suitable containers and are prepared to lift them out and divide them when they get overcrowded, most plants will not get out of control, BUT if you allow the plants to root in the sediment so that they can spread at will, then small and medium-sized ponds can soon become choked with the more vigorous kinds. For this reason, vigorous plants, such as the larger varieties of waterlily Nymphaea, brandy bottle, Nuphar lutea and marginals such as cyperus (Carex pseudocyperus), soft rush (Juncus effusus) and water mint (Mentha aquatica) are a really only suitable for a large pond.
Planting your pond
Pond plants are best planted in spring, so they have plenty of time to get established but they can be successfully introduced at any time during the growing season. I recommend that you choose a sunny warm day to make the job more pleasant. Use a special aquatic basket with lattice-work sides to plant both marginals for the shallows around the edge of the pond and for deep-water plants such as waterlilies.
It is also important to use special aquatic compost which releases nutrients slowly otherwise the pond water will turn green with algae. After planting, cover the surface of the compost with a 2cm (1/2in) layer of washed gravel which will prevent fish from stirring up the compost. Plunge each basket into a bucket of pond water until the air bubbles stop coming out of the compost. Then place the plant and container in the pond. Stand waterlilies on bricks so that their leaves are just below the surface. As the leaves grow, lower the basket in stages until it is sitting on the floor of the pond. Alternatively, trim off all the mature leaves and position the plant directly at the correct depth. All new leaves will naturally extend until they reach the surface.
Stocking with fish
Once the pond is planted, wait for about a month for the plants to settle in before adding fish. Pond fish are normally supplied in polythene bags in which you transport the fish from the aquatic centre or pet shop to your pond. It is important to do this carefully and quickly to minimise the shock to the fish.
Once home, keep the fish in a cool place, such as a garage, until early evening. Then carefully float the bag containing the fish on the surface of the water for about an hour. This will allow the temperature of the water in the bag to slowly cool to that of the pond. If the pond is still in direct sun, cover the bag with a piece of newspaper to shade the fish. After an hour or so, open the bag up and allow in a little pond water and leave for another ten minutes before releasing the fish from the bag.
If you are creating a wildlife pond and want to stock your pond with other creatures, the easiest way to do this is to ask a friend with an established pond if they could scoop out a bucketful of sediment from their pond, then pour this into yours. In the spring you can also introduce frogspawn. But in the interests of conservation, never creatures from the wild.
How many fish?
When stocking a new pond, allow up to 25cm (10in) of fish for each 1m² of surface area. Therefore, for a pond with a surface area of 5m² you should not add any more than ten 12cm long fish. This will give the fish plenty of room to grow.