The UK has a level of biodiversity which places us amongst the bottom 10% of countries in this world. Endless experts and scientists consider the use of pesticides to be a significant factor in this decline. Pesticides are not discriminating, they will kill the many beneficial creatures as well as the pests. But if we don’t spray, how will our plants survive attacks by pests? Companion planting is one strategy, by simply placing protective plants close to those we want to keep pests from eating.
Insects rely on their strong sense of smell over long distances. Growing just one type of plant that they love (like vegetables) holds up a flag to them: “Here we are – come and get us!” And they will! Vegetables smell irresistible to pests. By mixing in a range of aromatic, highly scented herbs, which give off a scent so strong that it irritates the systems of many pests and hides the more attractive smell of your vegetables, pests will keep away. Plants such as rosemary, lavender, mint and basil contain linalool, a chemical whose smell can overwhelm insects. Planting them around your vegetables will help to deter pests.
Chives contain pungent sulphurous compounds which disguise the smell of your vegetables or flowers, so aphids fly on by! Fringe vegetable patches with chives and plant French marigolds in the greenhouse as their smell deters aphids that might be tempted in by the attractive aroma of tomatoes.
Another strategy is sacrificial planting. What’s this? Simply put, it’s offering the insects something more tempting to keep them off your special plants! Nasturtiums, abundant in sweet nectar, pollen, and soft sappy growth, are the ultimate culinary delight for many pests, such as black fly. Push seeds into the ground near crops. This highly prized treat attracts pests away from other plants. They love to suck nasturtium sap and then lay their eggs there rather than move over to your vegetables. In this way nasturtiums act as a sacrificial alternative.
Next, why not attract beneficial insects who will eat your pests?! Ladybirds and Lacewings, and especially their hungry larvae, eat insects in vast quantities. These are your very best friends. Grow lots of flowers to attract them. They fly in for nectar, spot your pests and gobble them up, then lay their eggs on your vegetables thinking the pests will be a good source of food for the soon-to-hatch larvae who eat around 100 pests a day! I have seen ladybird larvae on a runner bean area, solidly black with infestation, clear the beans in about a week!
Had you sprayed, this would not have happened: you would have killed the lacewings, ladybirds and other beneficial insects, your vegetables would have contained toxic residues and your flowers would have contained toxic pollen and nectar, which visiting insects would have absorbed.
Kate Southworth
