hi jo
I’d strongly recommend a fruit-cage – by taking birds out of the equation you’ll find the increase in productivity is extraordinary (I’m very fond of birds, just not so fond of them gorging themselves on my soft fruit!) – but there are some disadvantages too which I can briefly list which you might want to take account of when planning dimensions. The first is cost particularly if you’re going to use metal supports and quality netting to stand the test of time (Agriframes at
http://www.agriframes.co.uk/index.php
and Harrods Horti (not THE Harrods as far as I’m aware though the prices might suggest otherwise…) at
http://www.harrodhorticultural.com/H...me/default.asp are two suppliers of fruit cages and accessories and both have cost calculators of different dimensions you might find offer useful comparisons (or how much you’re going to save if you’ve other means). The wider winter netting that Rat mentioned isn’t 100% essential and you can allow the birds free reign to reduce insects etc once cropping is finished but whatever you do don’t leave the smaller mesh in place over the winter because a sudden snowfall doesn’t necessarily break the net but collapses the whole structure (ask my brother and he lives well South of London, it was a total and expensive write-off.) The second problem – well, not a problem as quite enjoyable – but fruit cages are quite labour intensive particularly if you’re intending to save space by growing some things as cordons; careful pruning is also essential. So bear in mind in planning overall size you need to plan in adequate access paths and soft fruit bushes grow bigger and faster than you think (well, bigger and faster than I expected anyway!

) and raspberries in particular are no respecters of pathways… If bushes and pathways get too out of hand you can’t get in to sort them out

so they all do need regular maintenance. Also if too crammed, plants start competing for light and nutrients so allow very adequate growing space (and particularly in the case of gooseberries adequate cropping space because they can be spiteful if tangled).
To give you a more precise idea about size I have one that is approx 16 x 20 feet and it houses (housed!) 3 red/white currants, 3 blackcurrants, 3 gooseberries, row of raspberries (standard at one end, autumn at t’other), a (not very productive) cordoned cherry, a blackberry and a loganberry (and initially a small bed of strawberries but they soon got submerged…). The blackberry became rampant so I took it out (prefer the wild ones anyway) and because the plants are now ageing I'm replacing and over time reducing the “three of each” currants/gooseberries to “two of each” and will reintroduce strawberries next year. The thing to bear in mind is because you’ve taken birds out of the equation (though they still occasionally get in, don’t ask me how – and then of course can’t get out without some assistance…) you significantly increase the crop so need fewer plants. The other wildlife that increases is field mice – I don’t know whether field mice eat fruit (they always look very healthy with nicely conditioned coats!) – but they probably particularly value being protected from owls -- it must feature as an Executive Gated Village in Field Mouse World!
Problems apart, without doubt it’s one of my favourite areas of the whole garden – hope you go ahead with your plan, enjoy it and reap the benefits.
bb.
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