Why berries need a cage, and what it should do

Any gardener who has grown blackcurrants, redcurrants, gooseberries or blueberries will know the feeling: the fruit swells, colours up beautifully, and then one morning the bushes are stripped. Blackbirds are the main culprits, though pigeons will peck at gooseberries and bullfinches have a particular fondness for currant buds in late winter. A fruit cage is simply the most reliable answer — not a fortress, just a light, well-made box of timber and netting that keeps the birds out while letting in light, rain and pollinating insects.

The cage described here is a permanent frame with removable netted panels. That single design decision makes all the difference. You can lift a side panel out to pick a bucketful of redcurrants without ducking through a doorway, and you can take every panel off at the end of the season to prune, weed and mend the netting on a bench rather than on your knees.

Choosing the site and size

Currant and gooseberry bushes are happiest in sun for part of the day but will tolerate light shade, and they dislike sitting in water. Pick a spot that drains freely and is not shaded by a shed or hedge on the south side. Allow roughly 1.5 metres between bushes, so four established bushes need a footprint of about 3 metres by 2.4 metres. If your bushes are still young, build the cage for the size they will be in five years — extending a timber frame later is fiddly and rarely looks neat.

Height matters more than you might think. Aim for 1.9 to 2.1 metres at the eaves. That gives you room to stand upright inside, and it lifts the netting well clear of fruit so blackbirds cannot peck through the mesh from a perch on the top rail.

Materials that last in British weather

Use tanalised timber throughout; untreated softwood will be soft at the base within three seasons.

• Corner posts: four lengths of 75 x 75mm tanalised timber, 2.4 metres long, set 300mm into the ground in concrete or driven into metal post supports.
• Top rails: 47 x 75mm timber to run around the head of the posts, plus one central rail if the span exceeds 2.5 metres.
• Panel framing: 47 x 50mm tanalised batten for making up the removable side and roof panels.
• Netting: UV-stabilised black netting with a 20mm mesh. Anything larger and blackbirds will push through; anything much smaller shades the crop and catches leaves.
• Fixings: galvanised staples, 100mm screws, hook-and-eye catches and a few small stainless hinges if you want one panel to swing rather than lift.

Building the frame

Mark out the rectangle with pegs and string, checking the diagonals are equal — a frame that is out of square will never sit flat. Dig or drive the four corner posts, then set the top rails so their upper faces are level. Screw through the posts into the ends of the rails rather than the other way round; it is a much stronger joint. Add a mid-rail along the longer sides if the span is over 2.5 metres, and one across the middle, which also gives you something to hook the roof panels onto.

Give the whole frame a coat of wood preservative on any cut ends and let it dry before the netting goes near it. Fresh creosote-style treatments can damage netting; water-based shed and fence treatments are kinder.

Making the panels removable

Each side panel is a simple rectangle of 47 x 50mm batten, screwed together with the joints overlapping so the corners are solid. Lay the frame on a flat surface, drape the netting over it, and staple it to the underside at roughly 100mm intervals, pulling it taut as you go. Then screw a slim batten over the stapled edge to sandwich the netting — this stops it tearing loose in a gale and looks far tidier.

To hang the panels, fit two hook-and-eye catches near the top of each opening and let the panel rest on a small galvanised bracket or a rebated block at the bottom. The panel lifts straight up and out, taking two seconds. Make the roof in two sloping panels rather than one flat sheet, so rain and snow slide off and the netting does not sag into a puddle. Hingeing one side panel on a pair of small hinges is a worthwhile luxury if you visit the cage daily.

Looking after the cage through the year

• Spring: check for tears where branches have pushed against the netting, and repair with fine garden twine or a patch stapled over the hole.
• Summer: lift a panel, pick, and refit it. Netting left open for "just a day" is how most crops are lost.
• Autumn: remove the panels altogether after picking so birds can help themselves to any leftover fruit and keep the bushes clean.
• Winter: store netting indoors or flat under cover. UV light and damp are what kill netting, not age. Brush the timber down, check the post bases for rot, and touch up any preservative.

Done well, a fruit cage will serve you for fifteen years or more, and you will wonder how you ever managed without one. The berries, incidentally, taste all the better for being picked standing up.