How to fight slugs and snails using companion planting

Slugs and snails can ravage a garden. Here are a couple of examples in my garden, where companion planting almost eliminated snail damage in swiss chard and beets.

Scientists prefer the term INTERCROPPING instead of Companion Planting to describe the benefits of plants on each other. If you do a search using "intercropping' you're more likely to get fact based results.

Turnips protected it's swiss chard and beet neighbours

We had a very wet spring and early summer and the slugs and snails loved it. Everything was green and luscious. The snails prospered and multiplied.

2 snails on my handsnail on a turnip leaf

Snails can reproduce very quickly because they are hermaphrodite and both parents can become pregnant and lay eggs. I you have 2 snails they can breed together and reproduce.

Many of my plants started looking like lace handkerchiefs in no time at all. I started patrolling and picking off the offending snails and this helped. I also noticed that some birds were carrying off adult snails.

turnip leaf chewed by snails and slugs

The snails and slugs are very fond of plants in the cabbage family. Collard greens, broccoli and brussel sprouts, kale and turnip, are all favourites. They will also happily munch on beet leaves and swiss chard. A few hungry snails will devastate your greens in just a few nights.

One day as I was frantically hunting the slugs and snails, I noticed something very strange. The turnip were being shredded but right beside them, and touching, the swiss chard was practically un-munched.

swiss chard is almost untouched by slugsbeets are almost untouched by snails turnip and chard side by sideturnip had a faster start

In spite of the large number of snails around there was almost no damage to the chard nor to the beets one row away. A few inches beside them the turnips were disappearing as I watched.

When they first came up the turnip was blindingly fast and quickly got to the business of making lots of leaves and making the turnip. This happened before the snails had a chance to build up their populations but they slowed right down when the snails showed up. The chard quickly caught up.

I had planted the turnip more as an experiment than serious vegetable production. As it turned out the turnips came up well and quickly made tasty turnips and leaves. They then became slug magnets and kept the swiss chard and beets virtually free of snails.

Now I know, IF I WANT TO KEEP A PLANT SLUG FREE I SHOULD PLANT TURNIPS NEAR IT. Or rather plant a cabbage family vegetable. Even simple radishes will help.

The nice thing about turnips and radishes as bait plants, is that even if the leaves get eaten you still get the turnip and radish so there is not much loss of crop.

It's much easier to check a few plants for pests than several rows so I was able to do a much better job of picking off the snails, in a much shorter time. For this to work you have to go and pick off the snails but they are concentrated in a much smaller area. Organic farmers will sometimes plant a row of bait plants. When they are full of pests these can be picked off or the plant carefully sprayed with a pesticide. This way the real crop remains intact and is not sprayed with pesticide.

Collard Greens and Swiss Chard.

Further down the garden path as it was, the collard greens were also doing a similar job for the red chard.

red chard and collard greencollard greens and red swiss chard

The collard greens are not as devastated as the turnip greens but the red chard is almost untouched by the many slugs happily sitting on the collards.

Organic farmers know this

Planting a sacrificial variety near another type of plant we want to protect is well known tactic of organic farmers. Not only does this keep the pests away from the wanted crop but it concentrates the pests in one area where they can be trapped or squished, sprayed, or removed.

I did a bit of research and found a number of references where plants were used to lure pests away. These examples are from Swanson Nursery website: Agastache, will attract cabbage moth away from the garden, Calendula also attracts slugs away from other plants, apparently Nasturtiums attract aphids away from other plants, radishes attract leaf miners which sometimes plague spinach and beet or chard leaves.

West Coast seeds has an extensive page on companion planting.

The official term used to describe the practice of planting a crop for the purpose of attracting pests from a more desirable crop, is CROP TRAPPING. Here is a link to a youtube webinar on how organic strawberry farmers are using crop trapping to keep Lygus Bugs in control. They regularly go in and vacuum up the bugs from the lure crop and the strawberries are the winners.

From the University of Vermont: Controlling Pests with plants: the power of intercropping.

I think the take-away for me is this:

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This information is for general knowledge. I don't claim to be an expert on anything. The information on this page comes from personal experience.

email: Christine