Wildlife ponds can attract a wide variety of native visitors to a garden: Michaela Strachan shows how to create the perfect pond.
Last month I explained what NOT to put in your garden ponds, this month Iím going to tell you how to make a wildlife pond. There is no better way to encourage wildlife into your garden, and although people say that spring is the best time to create a pond, in reality you can build it any time you like and plant from early spring through to autumn.
Its size will depend on your garden, but with wildlife ponds bigger is better if you want to attract a diversity of species. Having said that, anything is better than nothing, even a bowl of water is appreciated by garden visitors, but a minimum area for a proper wildlife pond would be about 2.5 by 2 metres. Try to choose a sunny area away from overhanging trees, unless youíre building a really big pond and have a couple of weeping willows standing about!
How do you go about building your pond? First youíll have to do a bit of hard digging! The hole should be at least 77 cm deep to stop the pond from freezing during a harsh winter, and a variation of depths will be the spice of life for its inhabitants. Create shallow edges for plants and slopes that allow easy access and escape for animals, especially the occasional clumsy hedgehog. You can buy a pond lining, but itís better to make your own and customize it to your chosen area. Remove any stones and line the bottom with sand, then old carpet. (It sounds strange I know, but this will prevent anything growing through the next layer and puncturing your pond.) Lay a butyl rubber lining on top of the carpet. Youíll need the length of the finished pond _ twice the depth _ the width; itíll be a lot of rubber!
What next? Fill the pond with water and leave for at least a week before adding plants. A good tip is to get permission to take some mud and water from a healthy, established wildlife pond: youíll be amazed how many beasties it can kick start. If you need to top your pond up use water from a garden water butt.
So, which plants? Well Iíve got one word to say and I canít say it often enough, NATIVE! If you want to attract native wildlife then plant native species. Plants are the basis of a good wildlife pond and a diversity of species and variety of density are important. Try to include submerged plants to oxygenate the water; plants with floating leaves for shade and shelter; plants that emerge and stand up, for dragonflies, and have some dead wood or logs lying partially in your pond, for a great habitat.
Some recommended plants:
Native oxygenators: Curled pondweed, hornwort, water milfoil and water starwort.
These keep the water clean, support microscopic creatures and provide food for water snails. Plant them in the deepest area of the pond and anchor them down until theyíre established.
Native floating-leaved plants: Water lilies are excellent Ė the fringed variety are best for small ponds. Amphibious bistort, potamogeton, common water crowfoot and frogbit are also good.
Native marginals: Bog bean, flowering rush, brooklime, ragged robin, rosebay willow herb, lesser reedmace, lesser spearwort, marsh marigold, water mint and yellow flag iris.
A few doís and doníts:
Do try to include a boggy area, another great wildlife habitat.
Do allow some organic matter to get into your pond since it provides shelter, food and somewhere for egg laying.
Do leave rough patches around the pondís edge; this will provide an extra wildlife sanctuary.
Do leave the pond alone, itíll take time to settle down. There may be a build up of algae and pondweed, but water snails should keep these under control and you can buy extra snails from a pet shop (native ones, needless to say). If you have to clear out any pondweed, make sure you leave it by the waterís edge before composting it so that any wildlife can crawl back into the pond.
Donít put fish in your pond, especially goldfish. Remember my all-important word NATIVE: fish will devour all the native invertebrates and tadpoles. I know they look good but if you want native wildlife theyíll to have to go!
Donít introduce frogs, toads or spawn from the wild in case they bring disease. Be patient and they should come naturally or make absolutely certain that they are from a healthy source.
Donít use exotic plants.
Finally, remember that youíll need patience. Itíll be at least a year before you see any results but once your wildlife pond is established, it will be extremely satisfying and no doubt give you great pleasure.
So good luck and keep gardening wild!