Garlic has many health benefits, and growing our own is easy when you know how. Homegrown garlic has only the chemicals you apply, and you can eat the leaves and flower-stems when they are young. Planting garlic in a tunnel or glasshouse now can give you bigger and earlier bulbs than outdoor crops, but even starting a crop in modules or pots under cover and planting it out later gives some benefit. It stops the birds pulling them up too.
The ideal soil for garlic is light, well drained, moderately fertile and neutral or alkaline. Wet sticky clay can rot the bulbs and very rich soil encourages leafy growth at the expense of the bulbs. A good supply of potash helps, so dig in some wood ashes before planting. Garlic needs a long, cool growing season and a cold spell to stimulate maturity, so autumn planting is ideal. However, you need to choose your material carefully.
Do not plant shop-bought garlic and expect a decent crop; you may be lucky but it is sold for eating rather than planting and may be treated to inhibit growth, or carry plant diseases that will persist in your soil for many years. Get disease-free sets of varieties suitable for autumn planting from a garden shop or centre. Gently split them into cloves, and plant the bigger ones 2-5cm deep into the soil 15cm apart, in rows about 30cm apart, with the pointy end up and the flat base down. Plant the small cloves close together to produce leaves like chives. Water the crop lightly and let it dry out between waterings to prevent rotting. Dig up the bulbs gently when harvesting, and avoid pulling them. They bruise easily and then will not keep. Dry and store them in a cool, airy place.