To the waters and the wild

Sat, 05 May, 2018 - 01:00

Kya deLongchamps looks at creating an indigenous wildlife habitat by introducing a wetland or pond area to gardens big and small

We’re all a bit over-excited right now at Fortress deLongchamps because I’ve finally persuaded the powers-that-be to make a place in the garden for a wildlife pond.

What makes this type of garden installation different to an hotel for undulating koi, is its invitation to the indigenous creatures from frogs to dragonflies, pipistrelle bats to pond skimmers to come on down and dive in.

If you only have a yard for a garden, you can still include a wildlife pond using a half barrel or old sink, just ensure any creature that gets in, or falls in, can get out. Any pond can and should include elements that will help native wild things to thrive.

And It’s very easy to accommodate their needs with a graduated bank and a final, shaggy finish around the edges of a pond.

Frances Gallagher of Rinn Bearna Aquatics and a marine biologist, has this advice to give:

“A birdbath will help birds and small mammals in dry or very cold spells. A shallow water feature containing untreated water, will help amphibians to rehydrate, and increase their available habitat.”

“You may feel that your garden, or your child, is too small for a pond. You may be right — but any permanent area of water in a garden is useful to wildlife.”

Any pond, even a small upright body of water, can be adapted to wildlife needs, year round. A pond is really a small wetland and it’s a fascinating project that with a little encouragement, will quickly develop a life of its own. First of all, position is important.

If, like me, your garden has some sunny but unkempt, disreputable areas with unplanned plants (weeds) and boggy areas (drainage issues) – a pond around 1mx2m or more, could be just the thing.

Shape can follow an available area – and joining the water itself to other habitats, like piles of cleared stones, soft ground and shaggy grass, encourages diversity. Finally, all that neglect will read as worthy ecological intent— hurrah!

If you have small children (under six), the pond should be inaccessible, while netting etc should be used to prevent incursions and constant adult supervision is a non-negotiable precondition.

Fish? If you want ornamentals, think about creating two ponds – one for the invertebrate devouring fish, and another for the naturally-occurring wonders. Keep away from overhanging trees and excessive shade (some afternoon shading is fine), and once you’ve decided on what room and shape you have available, aim to dig out a well-oxygenated pond at least five times its surface area compared to its deepest point (up to 10 times is better).

The deeper you go, the larger your pond must be. It’s not a horrible dig out, as most of your pond will be a reasonable 30cm, just over a standard digging spade’s depth.

Terrace the depth through 30-60cm shelves, but these shallower areas of just a few centimetres are crucial and will rise gently to the pond’s edge and right into the grass through a range of planting.

“Access to the pond is very important to wildlife, so a shallow sloping ‘beach’ area is essential,” says Frances Gallagher.

“An area of emergent plants — grasses or flowering plants are both good — also allows creatures to enter and leave the water safely.

“Steep upright sides are bad news for frogs and lethal for anything that might fall in, such as shrews, hedgehogs and other small land mammals.”

A successful pond can work at depths as shallow as 40cm. As we’re trying to introduce a range of habitats common to natural wetland, what about a micro-bog?

Bog gardens used alone, are also safe for children who can watch them grow and develop over the entire year. A clever tip to start a bog garden by itself or by the side of any pond, is to put a cheap pond liner or shallow paddling pool (truly cheap — bordering on disaster), and place it in the ground before deliberately piercing it a few times. Fill with soil. The ‘bog’ will collect rain and drain more slowly than the surrounding ground.

Getting back to the main pond, check the levels after you dig out using a long board set from one shore to the other and topped with a spirit level. Use stones or old blocks to create a bank, if one side is lower than the other, to retain the water.

Keep the sods and use them to hold down the edges of the pond liner well out of the water. Having cleared out any big, sharp stones, old carpet is fine for underlay for the liner if you want to save money, but invest in proper flexible pond liner to top that — the kind that won’t easily puncture.

Size-wise, there is a debate on depth, some experts suggest a minimum of 75cm going down to 90cms at the deepest point to prevent the water freezing through in a sharp winter.

Others suggest that shallower ponds of 25-30cms can work if there is enough dissolved oxygen in the water, produced by submerged, oxygenating plants, or the old trick of putting a floating ball on the water to break up the ice and allow a breathing hole, also works. Shallow areas of 20 cms, graduating towards the edges, will also allow more bog planting and offer birds a place to bathe and drink. The base of the pond can be covered with sand or washed gravel, which is ideal for burrowing dragonfly larvae.

Rain water (low in nitrogen and phosphorus), is ideal for garden ponds and really essential for wildlife ponds.

Install a rainwater butt to collect your own and use this to top-up where necessary in summer. For the rest of the time, the biggest job will be maintaining your patience.

Plants that take off can be thinned out but don’t bald out your pond of more than 25% of growth. Excess fallen leaves should be removed — a few will be a welcome area of complex underwater architecture for swimmers.

“Use native plants wherever possible, but be aware that some pretty aquatic plants are invasive and can threaten native habitats when they escape,” warns Gallagher. “If you spot any invasive or non-native Irish species, get them out of your pond immediately and take them away from the water’s edge.

“It may take a year to see your first frog — but it will be well worth the wait.”