We’ve already overcome the rabbit problem in the vegetable garden (or Colditz for Bunnies) by fencing with small-gauge wire netting that’s 1 metre tall and buried 6” deep with the lower end of the netting turned out 90 degrees. It was a heck of a lot of work, but paid dividends in hugely increased yields – previously anything green sown or planted direct into the soil rarely made it beyond seedling stage! Gates and other entrances must also be rabbit-proofed and kept closed when not in use.
Another method of deterring rabbits from your garden is the use of electric fencing – you would need about six strands spaced three inches apart. They’ll just jump it if not high enough. You can also user a timer with this method so that the fencing is only active evenings and mornings when rabbits generally feed.
For individual trees, try using tree guards – cylinders made from poultry netting or plastic mesh that need to be taller than the rabbits reach. Readily available commercially.
Having dealt with the rabbits, the slugs recognised their opportunity and colonised the cabbages and lacerated the lettuces! I hate the idea of slug pellets as they can be a source of secondary poisoning to so much wildlife (look for organic ones if you do use them), so, I searched for effective, economical natural control methods – and I was very surprised how many there are. These are my favourites:
Encourage wildlife – toads, frogs, slow-worms, birds and hedgehogs (so rare these days, you don’t even see many road casualties) all eat slugs; we have a small garden pond near our plot which is a breeding site for dozens of toads each year, so I just need to encourage them to spend time around the veg plot …
A little untidiness – (I like this one!) a few heaps of damp leaf mulch will provide a nice environment for frogs and toads, and slugs will choose the decaying leaves in preference to your veg
Raking the garden – this will expose slugs’ eggs to the birds and is good exercise!
Hoeing – (more good exercise) leave the weeds to wilt, the slugs will eat these in preference to growing plants
Nematodes – these are microscopic worms that parasitise and kill slugs – they will remain active for about 6 weeks and are quite costly, so use them on your most vulnerable, precious crops. Wiggly Wigglers is a great online shop for this - http://www.wigglywigglers.co.uk/wildlife-garden/natural-pest-control.html
Wool – a great mulch, we use ‘daggings’ from our sheep which both fertilises the plants and makes a scratchy surface that slugs don’t like to cross. We tuck clean wool around the base of strawberries and this also stops mud splashes on the fruit when it rains.
Eggshell & gravel – scatter around your plants to form a protective barrier
Copper – there are a number of copper products to deter slugs including rings to put around plants and copper tape to put around pots - this can be quite expensive though and I haven't had much success with this method.
Kelp – scattered around your plants, the salt in the seaweed makes a great deterrent - don't put it directly on your plants though (a great tip from Martin Duncan, chief gardener at Arundel Castle).
There are numerous other methods (including beer traps, but we deemed this wasteful).
There are also numerous vegetable pests that can create havoc in your garden. It can be heart-breaking to find a small plague of green or black aphids covering your lovingly tended crops. Organic pesticides are widely available but they can also affect the beneficial insects in your garden. If caught early enough, you can remove that section of the plant or just wipe them off with kitchen paper and squish them. Planting basil, chives, dill, fennel, garlic, or mint can act as a deterrent. Wiggly Wigglers provides nematodes for vine weevil, leatherjackets, ants and other garden pests - http://www.wigglywigglers.co.uk/wildlife-garden/natural-pest-control.html
Caterpillar damage can be just as devastating. The best method for this is to inspect your plants regularly and pick off the caterpillars. Nematodes are also available that will infect the caterpillars and kill them. Available from Nematodes Direct - https://www.nematodesdirect.co.uk/10-nemasys-caterpillar-killer