Soggy sounding words like bog, swamp or marsh may not immediately conjure up visions of successful vegetable growing, but wet areas are actually a really important part of the ecosystem.
Wetlands are defined as transitional areas between dry land and deep water, including habitats like rivers, streams and lakes, as well as flood meadows, peatlands, marshes and estuaries. On your plot, it’s that boggy spot where drainage is slow or the pond you’ve built in the corner.
The bigger, wetter picture
Three per cent of the earth’s surface is classed as wetland, and it’s a habitat that is under constant pressure. Huge numbers of humans find themselves living on what used to be wetland areas, which are now partly concreted over and less absorbent. As climate change scientists warn of rising tides and the ever higher risks of flooding, perhaps it’s time we started valuing the boggier aspects of life a bit more.
After the devastating UK floods in 2007, the Pitt Review concluded that the extent of the flooding was exacerbated by unsustainable management of land and water. The Wildlife Trusts argue that, in the past, the landscape around towns and cities and in upland areas absorbed water like a sponge.
Today, rain falling in the uplands often cannot soak into the ground, because drainage and erosion have damaged peatlands, and soil has been compacted by intensive grazing and farming.
Housing and arable land have replaced wet grassland and grazing marsh areas on many floodplains, taking away natural storage spaces for water. Concrete and paved over spaces like car parks, streets and some gardens can’t soak up water. Intense rainfall can quickly overwhelm some urban drains.
In the rush to increase agricultural production and expand towns and cities, water has been squeezed out of its natural space. And it’s not just about flooding – many species of wildlife need wetlands in order to survive.
In the face of all this, gardens and allotments, with their soft, absorbent surfaces, are incredibly important for both people and wildlife. Adding some wet areas to your plot will have benefits for the wider environment but will also encourage useful predators like bats, birds, frogs and toads, as well as adding aesthetic interest.
Damp loving plants can be very beautiful and there are even some crops that love wet conditions. Water mint makes as good a cup of tea as ordinary mint, comfrey is an invaluable green manure crop and the jewel-like fruits of cranberries are a pleasure to try and grow. Or why not give water cress cultivation a try?
Dig a pond or a build a bog
A garden pond, however big or small, is one of the best ways of attracting wildlife into your garden. Even small ponds can support a rich diversity of wildlife and provide places for various species to bathe, drink and mate. A series of ponds in a neighbourhood creates essential corridors for wildlife to move and adapt to changing temperatures. Ponds also store large amounts of carbon, helping to reduce the impacts of climate change.
Anything can become a pond, in one of London Wildlife Trust’s sites an old roll top bath looks rather majestic as one, but it is best to construct a purpose designed pond, with easy routes in and out and plenty of pond-side shelter in the shape of marginal planting. A pond can be dug at any time of year and shouldn’t take very long.
You can download a free guide to making one from www.wildlondon.org.uk/gardening, but the key things to consider are location and liner choice. A level, sunny spot away from falling leaves is best, while flexible butyl liners are preferable to pre-moulded or concrete ones.
Creating a bog garden is even easier than making a pond, requiring a lot less digging! If you already have a place in your patch that naturally has poor drainage, you can set this aside for plants that favour wet conditions.
To make a boggy area from scratch, mark out an area, dig down about 30cm and cover the space with a pond liner punched with a few holes (for slow drainage). Refill the area with soil and a water retentive fibrous garden compost, and then water. Plant with bog loving plants and keep it wet with rain collected in your water butt.
Water loving crops
Comfrey: organic growers should consider having a comfrey patch in their garden or allotment, as its leaves can be turned into an effective, green feed. Comfrey really likes soggy conditions so if you have a damp area it should do well there.
Cranberries: the plants are low-growing, creeping shrubs that grow best in damp, acidic soil. Try digging a sunken bed in the garden, lining it with perforated black plastic and filling it with peat free compost.
Water cress: traditionally grown in running water, it’s possible to grow water cress from seed in standing water. Sit pots of the plants in bowls full of water in a shady spot and change the water every couple of days. Remember to re-use the old water elsewhere on the garden.
Water mint: able to grow on pond margins or fully submerged, water mint adds welcome colour and fragrance with its large pinkish flowers and strong menthol scented leaves. Small tortoiseshell and peacock butterflies love this plant, which also has numerous culinary uses.
Damp lovers – plants that like it wet
Purple and yellow loosestrife
Yellow flag iris
If you do one thing
Protect the world’s bogs and fens, which provide a home for many rare plants and animals as well as acting as vital carbon stores, by refusing to buy peat products. Choose peat free compost and only buy plants that are grown in peat free soil. There are many alternatives to peat that are just as good if not better at nourishing your plants, not least homemade garden compost, which has the added bonus of being free.
This article appears in the July issue of Kitchen Garden magazine