Companion Planting is based on the idea that certain plants benefit others when planted among or close to each other but... does it work? Here are some recognised 'good companions'.• Tagetes ( French Marigold) with Cabbages, Beans, Tomatoes and Potatoes.This half hardy annual deters whitefly and cabbage white butterflies with its smell, and the flowers attract predators such as lacewings and hoverflies to eat aphids, and its roots secrete a chemical which reduce eelworm attack. It also looks pretty! Sow some seed now.• Mint, Sage, Thyme and other strong smelling herbs with Cabbages and Carrots.The smell of the herbs confuses cabbage white butterflies and carrot flies. Ladybirds like to lay their eggs on Sage.• Spring onion and Calendula with Carrot.The strong smell stops carrot flies finding the carrots.• Tall flowers such as Nicotiana (Tobacco plant) and Sweet Peas with lettuce.These provide shade and humidity preventing scorching and delay bolting, a particular problem in hot dry summers.• Poppies, Nasturtiums, Calendula (Pot Marigold) and Poached egg plants.Their open flowers attract hoverflies which feed and lay their eggs on the plants, so producing larvae to attack aphids on all plants round about, and also attract pollinating insects to assist 'setting' on Beans, Courgettes and Squashes.• Pumpkins with Sweet corn and Climbing Beans.Traditionally these have been grown together to maximise the use of space, but also those prickly pumpkin stems deter raccoons! Whilst these particular pests have not yet reached our shores, the rats and badgers which enjoy our sweetcorn will be equally put off (hopefully).