Sanctuary

By Goldfinch

I mentioned in a previous article the concept of companion planting, an organic gardening practice that has gained popularity in recent years. As its name suggests, this invloves planting different species of plants together (as 'companions') in order to improve the health, pest resistance, appearance and/or yield of a plant, and, indeed, monoculture is not something that you will find in nature.

For centuries, gardeners and farmers have noticed that certain plants fare much better when grown alongside certain others. Conversely, some plants can have a detrimental effect on each other.

It is well known amongst organic gardeners that garlic and rose do very well when planted next to each other and this technique used by Bulgarian rose farmers. Garlic helps to protect the roses from infection and improves the scent of the flowers. At the same time, the garlic benefits from being next to the rose.

So why do some plants make such good companions? If we look at the example of garlic and rose, we know that garlic contains natural anti-fungal, anti-bacterial and insecticidal compounds and this helps to protect the roses from disease. In other pairings, it may be that one of the plants is attractive to pollinating insects, hence improving the yield of the other. Or perhaps one plant excretes the nutrients required by the other, or helps to improve the quality and the structure of the soil (e.g. alfalfa). Sometimes a sacrificial crop can be planted to lure pests away from a plant (e.g. nasturtiums will atrract aphids away from fruit trees). Or the reason may be simpler: that the companion plant provides the right amount of shade and protection from the elements.

Herbs make such good companion plants that a dedicated herb garden is really not necessary. Green leafy vegetables benefit from being interplanted amongst herbs. Try interplanting with lavender, rosemary, chamomile, basil and thyme.

Other good pairings are: basil with tomatoes; beans with carrots, potatoes or strawberries; dill with sweetcorn, lettuce, onions or cabbage; calendula with carrots; garlic with apricot, rose, peach or plum. You don't necessarily have to plant them together. As I mentioned in last spring's issue, simply burying odds and ends of the companion plant alongside the target plant can provide benefit (e.g. tops and tails of onions and garlic by roses), or watering/spraying with the companion plant's tea (e.g. garlic tea sprayed onto roses to prevent blackspot and enhance flowers).

However, some plants will not thrive when planted together. For instance, peas and beans should not be planted with garlic and onions (allium family). If you've tried unsuccessfully to grow certain plants, despite providing ideal conditions, bad pairings may be the cause. Other 'bad guys' are: basil with rue; sweet peppers with fennel or apricot; potatoes with parsnip, kohlrabi, squash family or fennel; tomatoes with potatoes (may infect each other with blight), cabbage or cauliflower.

Unfortunately, bad companions can be more complex than this. Some plants should be neither dislayed nor stored together. For instance, tulips and daffodils should not be displayed in the same vase - keep them on opposite sides of the room - as they shorten the lifespan of each other. Tomatoes stored with flowers will result in a mess of rotting vegetation! Apples also should not be stored with other plants.

You may need to experiment with the different combinations, as what works in one garden may not work in another. However, one plant which will almost always do your garden good is the much maligned stinging nettle. Keep a small restrained patch in the garden and harvest as needed to make a tea to water your plants. This tea will be high in nutrients and plant yields can be improved by up to 80%.

Ask Goldfinch

Dear Goldfinch,
I read in an article that non-native plants are bad for wildlife. Does this mean I have to get rid of all my non-native plants, because I really like some of them.
Lucy

Dear Lucy,
No, no and no! There is no reason at all why you should have to deny yourself your favourite plants and ruin your enjoyment of your garden, just because some of your plants aren't native.

Sunflower
Sunflowers: not so evil after all?

Native species are definitely better for wildlife in general, and species plants are better than showy cultivated varieties (which may not produce as much nectar as the wild 'species' form). However, this does not mean that anything non-native is inherently bad. Sunflowers, for example, are an excellent source of nectar for bees and other insects, and provide seeds in autumn for many birds, yet sunflowers are native to the Americas. Lavender isn't native to Ireland either - it's from the Mediterranean region - but is still cultivated in wildlife-friendly gardens as bees love it and the seeds are taken by goldfinches. I myself grow Pyracantha (another non-native) because I find it such a beneficial plant on all fronts: berries for the blackbirds, flowers for insects, and thorny cover for hiding and nesting.

Yes, it's true that there are native plants which can provide all these benefits and some say this makes non-natives redundant in a wildlife garden. In fact, a few people even go as far as to say plants should only be cultivated from stock originating within a 10-mile radius of the final planting site 'to maintain genetic purity' - stuff and nonsense! Anyone who subscribes to this is unfortunately a few hundred years too late! Our gardens, and the countryside around us, are already a mishmash of natives, cultivars and introduced species. Non-natives are really only a problem when they become invasive.

So my final say is, do go for native plants where possible, but remember, your garden is also for your pleasure - there's no need to be self-sacrificing. If you are fond of a particular non-native, there's no reason why you should have to give it up.