CRANBERRIES are the staple fruit of Christmas, creating the sauce synonymous with turkey or adding warmth to winter punches, relishes and jellies.

These beautiful deep red berries aren’t only popular with us though, they are also adored by wetland birds, so this year, Wildfowl and Wetland Trust wetland centres all across the country are holding their first Craneberry Fest — a celebration of the famous wetland fruit and an iconic wetland bird, the crane, after which cranberries are named.

From next Saturday, until January 26, WWT Wetland Centres, supported by Ocean Spray, will be showing visitors how to make beautiful cranberry decorations for the tree and cranberry bird feeders.

The plant was first named by early European settlers in America who felt the expanding flower, stem and petals resembled the neck, head, and bill of a crane. Most cranberries are still grown in boggy areas of North America and eastern Europe.

“Cranberries like boggy soil conditions and it’s quite difficult to create an environment in which they thrive in the UK,” says Leigh Hunt, principal horticultural adviser with the RHS. “But we can control the moisture and soil type by planting them in containers.”

The plants do have some visual worth, as they are evergreen and low growing, with pink bell flowers.

Cranberry ‘Pilgrim’, for instance, available from the RHS (www.rhs.org.uk) is a low-growing, evergreen cranberry with small, leathery leaves on lax stems that have an arching habit. Its attractive shape can be best admired when planted in a container so it can cascade over the sides of the pot.

The tiny pinkish-red flowers appear in spring and are followed by tart dark red berries, a regular superfood packed with nutrients and vitamins. ‘Early Black’ has a spreading habit, evergreen leaves and large dark blue, fairly sweet fruit.

If you have problems with drainage in your garden, the cranberry might actually be for you. They need extremely acidic soil, with a pH of less than 5, and semi-bog conditions. They prefer sun but will also withstand light shade.

If you’re planting them in the ground, dig a hole 40cm (16in) deep and line the base and sides with plastic sheeting. Fill with an ericaceous compost and mulch with 5cm (2in) of sawdust or wood shavings. Punch a few small holes in the sides of the plastic just above the bottom to allow water to seep out. If you can, use rain water to thoroughly wet the compost and trample it like grapes until the soil is soaking.

Keeping them well watered is really important and early to mid-summer is critical.

Most days you will need to check the pot. They have a shallow root run so a pot 12 inches deep would be sufficient and ideally you want a pot which is wide but shallow. In spring, feed the plants with sulphate of ammonia, sulphate of potash and bonemeal and top-dress with ericaceous compost.

If you are growing in pots you can control the conditions more effectively by spring planting in peaty ericaceous compost enhanced with around 10 per cent lime-free grit. You’ll need to keep the plants really wet, so stand the pots in wide saucers that remain topped up with water, particularly rainwater, as tap-water contains too much lime.

Feed the plants every week during the growing season with a product specifically formulated for acid- loving plants and you should be harvesting the berries in September and October. They will keep in the fridge for a good few weeks or you can freeze them or pop them on a tray in the oven on its lowest setting for a few hours to dry them. Once the dried cranberries start to look like raisins, they can be added to bird feeders.

To make a pine cone bird feeder, tie 24in of ribbon to the end of each pine cone. Coat each cone with lard and sprinkle with soft, dried cran-berries and bird seed. Hang with ribbons on tree branches.

n For details of the Craneberry Fest, go to www.wwt.org.uk