Any garden especially vegetable gardens will have resident slugs and snails. There is just no avoidance other than having to be vigilant with how you deal with them.
The question is how in an environmental and safe capacity. Yes by all means go out looking for them as they come out in the evening and at night, collect and move them , yet where to, how far away ? I know for many this would be the kindest way. However they probably will come back to gorge on your beautiful vegetables.
What crops do they specifically like:
I go from my experience here and how I tackle the slugs and snails. This will not be everyone`s choice and of course every Kitchen Gardener will need to decide the best way for yourself. I do aim to limit any treatment once certain crops grow a little sturdy. I have also experimented with various ways of dealing with them to reduce environmental impact to a minimum.
Crops to be vigilant with: My experience
Tiny carrot seedlings: If wet weather they will disappear to the where they emerge from the soil. And you will need to resow
Tiny lettuce seedlings: Once lettuce gets to a small plug plant size I will generally give no protection unless excessively wet weather. Certain lettuce are less attractive to these pests. Especially thicker leaf, frilly, serrated varieties. In warm dry weather I tend to give no protection at all. Watering directly around each plant when possible to encourage root establishment.
Baby spinach, chard seedlings: Although I tend not to protect unless very wet weather. Once a little bigger with thicker leaf they are generally fine. One will always get slugs and snail eating holes in some of these greens. Yet I would rather share than specifically use a slug deterrent or killer. Washing carefully when harvested is advised.
Baby Brassica Plants, seedlings: Another crop rather liked by snails and slugs, although I tend to go by the weather. If very wet when first planted or vulnerable emerging as seedlings I may add a deterrent. Once small plants they will not get destroyed although may be a target. I just share in some cases to reduce using a deterrent.
Baby cucumber, courgette, squash, pumpkin & gourds: Seedlings will be eaten to the ground so take care. Baby plants will also be devoured so protection of some sort is required. Once the leaf gets a little course which it does quickly they will be fine. The fruits will be a target when young however I don’t protect as I grow so many over quite a large area that I always have plenty to harvest.
Raised containers ideal to add copper strip to. Fine netting on brassicas for protection against cabbage butterfly can also be a deterrent for slugs as it is rough to move over . Slugs & snails like a smooth pathway.
Beans, French, runners, all climbing beans: Protection when young plants as the leaf will be totally demolished, broad beans and peas are fine.
Options to keep your crops safe:
Avoid watering your garden in the evening if you have a slug problem. Water in the morning the surface soil which will be dry by evening. You can reduce slug damage by 60-80% by careful watering. Water direct to the base of the plants to avoid soaking soil over the entire surface as they both like wet soil to slide over. Slugs and snails come out in the cool, especially at night.
Copper: Copper strips can be bought from garden suppliers which are suitable for vegetable and flower gardens. These come in various forms, widths and lengths. Small strips of copper can be placed around flower pots or raised beds as obstructions. Copper is a repellent and they will not move over it to get to your crops. These strips can be attached to the top or sides of raised beds or timber edging. Around containers, pots and any growing container or vessel. Copper barriers work well around wood barrels used as planters. Copper collars can alternatively be bought to slip around the base or neck of crops.
A non-chemical, non-poisonous living treatment is nematodes:
Tiny microscopic worms which feed on slugs and snails. They need to be applied every 6 weeks for total protection which can be expensive if you have a large garden. Ideally the most vulnerable seedlings or crops could be given a treatment if this is action is chosen.
Slug deterrent as wool or fibrous materials:
Slugs and snails do not like to move over dry fibrous materials or fabric; it sucks all the moisture from them and causes irritation. Here is a product on the market in more recent years. I am not sure of the source. However if you are concerned of the source may be you can find something similar which is totally environmentally friendly. Perhaps old wollen jumpers could be utilised in some way ? A little bit of recycling.
Slug deterrent as a granular material:
A safe and natural material, again slugs and snail do not like dry, rough, grainy materials.
Slug Gone & tiny seedlings which may be vulnerable to slugs & snails.
You can buy readymade slug traps which have access holes for slugs and snails yet once in they cannot get out. Beer, sugary water or slug bait can be used to entice them into the trap. They may well drown in these traps or you will have collected creatures to dispense of whichever way you choose. These are generally needed to be placed every 1-2m. Personally I found them fiddly and only used them once.
A cheap recipe would be:
1 cup water
1 teaspoon sugar
1 teaspoon flour
1/2 teaspoon dried yeast
Grapefruit & up-side down flower pots:
Up-side down empty grapefruits attracts these pests as nice places to rest after eating your lettuce which is cool and dark. They can be collected to be removed from your vegetable garden.
Most are harmful to wildlife and I certainly would not want to use them on my soil. A relatively new slug pellet based on iron phosphate, trade name Feramol, is approved for organic use.
Aim to try other methods first and avoid relying upon on pellets if you can although in very wet conditions one make need to resort to this organic approved method.
Recent studies show they do not like caffeine. As I see from research it will kill them if they are sprayed with a caffeine solution. The solution apparently has to be higher than the kitchen coffee so commercial preparations may be the only ones of use.
Frogs and toads are fabulous predators; I love to discover the local frog in my cabbages. So find a place for a water pool even if quite small.
Hedgehogs are well known for feasting on slugs and can be encouraged in the garden by providing a nest box.
Birds especially the thrushes love snails. If you protect from birds certain crops then obviously these will need to be snail and slug protected in another way.
Black ground beetles which you often find scurrying for cover when disturbed are less known predators. Be aware if you use beer traps then make sure the lip of the trap is above soil level so that the beetles do not fall in.
It is then crucial that you should not use any poison controls as all natural predators will be affected by these.
Other physical barriers:
Crushed egg shells although vegans will not be using this in the kitchen !
Products based on dried clay
Diatomaceous earth, will need to be replaced after rain
Wood ash and charcoal.
In the evening or early morning are ideal times. Damp spots, moist newspaper, weed suppressant fabrics or carpet is ideal cover for snails and slugs to find a hidey- whole. So make sure you check well. What you choose to do with them once collect is really up to you.
Enjoy your slug & snail detecting !