Organically pest controlling and soil enhancing a beginners guide to companion planting!
Aphids, carrot fly, nematodes and molluscs (slugs and snails to you or I) the blight of gardeners the world over, however if you have pets or small children certain forms of pest control such as slug pellets may be impractical, or downright dangerous, and with the advent of all things organic and raised awareness of the chemicals in our diets, I have managed to scrape together some information regarding the organic control of garden pests, by the strategic usage of other plants. Far from being purely for those erring on the flower child side of things, companion planting not only provides protection for the duration of the plants - meaning it requires minimal attention once everything's up and away other than the shaping you might ordinarily do, but also beautifies what can be utilitarian looking vegetable patches, beds or containers (the French refer to these types of garden as a potagers).
Companion planting works in one of 4 ways;
1) Repelling pests, for example: Mexican Marigolds roots have insecticidal effects on nematodes (tiny tiny worm creatures that eat your root veg) and seem to have repellent effects on certian types of slugs (keeled, but don't ask me to get close enough to ID them!).
2) By luring in carnivorous insects that eat the pests, such as ladybirds, hoverfly and lacewing- plants such as calendula, borage, echium, morning glory and nasturtium are usually good at bringing in the big guys.
3) You can use them sacrificially as decoys for your prized crop, for example, Mustard plants can be grown both for themselves and to protect crops such as cabbage, cauliflower, radishes, and turnips. Nasturtiums near radishes, cabbage, squashes, pumpkins and fruit trees will not only brighten up your patch, bed or container, but will see off a whole host of nasties, such as aphids and various squash and pumpkin beetles, and if they survive long enough, the flowers are even edible themselves!
4) It may be that the nutrients the companion plant takes from the soil are those that the plant it is a companion to doesn't use much of, and the nutrients it releases into the soil may be those that its neighbour needs, thereby creating a nice nutrient exchange instead of the 2 plants vying for the same resources and both suffering- happens even over water and sunlight- you will notice most vegetables that need a lot of water are incompatible with others who are equally heavily water dependent.
Although protective companions may themselves bring other problems, coriander for example, which protects almost anything from aphids, does tend to attract bees, mint planted to ward cabbage white butterflies, and aphids will take over your garden given the first opportunity and become a pest in its own right (My uncle advises growing it in a bucket without holes in the bottom). Ah the complexities!
So this is the real, absolute beginners guide to natural pest control using pretty common vegetables as examples- there are tons of combinations but trying to sort them into a useable format is beyond this one article(- stay tuned for part 2!). And so, if you are growing..:
CABBAGES:
Compatible with: Celery, Beetroot, Chamomile, Spinach, Bush Beans, Celery, Onions
Incompatible with: Dill, Strawberries, Runner Beans.
Protect with: Thyme (for Cabbage worm) Sage (for Cabbage Moth, Carrot Fly, Slugs)
Marigolds, Nasturtiums
CARROTS:
Compatible with: Lettuce, Rosemary, Lettuce, Onion, Peas, Radish, Tomato.
Incompatible with: Dill
Protect with: Chives (repel root flies) Sage (Cabbage Moth, Carrot Fly, Slugs)
CUCUMBERS:
Compatible with: Beans, Sunflowers, Radish, Corn, Lettuce, Onions, Peas, Radish.
Incompatible with: Potato, scented herbs eg: sage.
Protect with: Nasturtiums (Aphids, Squash Bugs, Striped Pumpkin Beetle) Marigolds
POTATO
Compatible with: Beans, Maize, Cabbage, Horseradish
Incompatible with: Pumpkin, Squash, Tomato, Cucumber, Sunflower
Protect with: Marigolds protect from nematodes and aphids.
PUMPKIN
Compatible with: Maize
Incompatible with: Potatoes
Protect with: Marigolds protect from nematodes and aphids.
STRAWBERRIES
Compatible with: Beans, Lettuce, Onion, Spinach.
Incompatible with: Cabbage
Protect with: Onions (aphids, carrot flies, moles, tree borers, and weevils) Borage
TOMATOES
Compatible with: Basil, Onions, Asparagus, Carrot, Parsley, Cucumber, Cabbage, Celery.
Incompatible with: Fennel, corn and potatoes
Protect with: Basil (Flies, Mosquitoes) Borage (Tomato worm) Onions (aphids, carrot
flies) Mint (Cabbage white butterflies, Aphids)
To my experience so far the theories seem to hold up, with the rare exception- there's always the one (or a few) particularly malicious slug or Biblically inspired plague of aphids that nothing's going to stop, but by and large I've had no dramatic losses since I started gardening like this. It's often lead me to planting new herbs which perhaps I wouldn't have planted otherwise but have reaped the benefits of later, or flowers that have lit up my garden whilst serving a purpose.
And best of all once your defensive plants are in, that's it! No going out to re-scatter the slug pellets after the rain, or worrying about the kids or next door coming over with a hefty vets bill. The garden takes care of itself.