UK crop guide
Garlic is planted as cloves, not sown as fine seed. Most varieties need a cold spell to split into a proper bulb, which is why the main planting time in the UK is mid-autumn to early winter. Some varieties are sold for late winter and early spring if you missed that window.
Buy named stock from a garden supplier. The RHS does not recommend supermarket bulbs: they may be unsuited to the British climate, and planting them can bring in disease.
Choose a sunny, free-draining spot. Wet winter soil invites rot. If your ground lies wet, start cloves in modules in autumn, keep them in a cold frame or an unheated greenhouse, and plant them out in spring.
Split the bulb into cloves just before planting. Set them pointed end up, 15cm apart, with the tip about 2.5cm below the surface. Space rows 30cm apart. In light soil the RHS notes that planting a little deeper can give larger bulbs. Birds sometimes tug new cloves out, so cover the bed with netting or fleece until they have rooted.
Most varieties need one to two months at 0 to 10°C to bulb up. That is the point of an autumn planting. Gardeners' World also repeats the tradition of planting garlic around the shortest day.
Module-raised cloves go out in spring, at the same 15cm spacing, once you are happy with the drainage. Do not wait for the tender-plant dates used for tomatoes. Garlic is hardy.
Water in dry spells in spring and early summer if you want fatter bulbs, but stop once the bulbs are well formed and the leaves are yellowing. Extra water then encourages rot. Snip off any flower stem as soon as it appears, and eat the young scape if you like.
Lift when the leaves have turned yellow. Autumn plantings are ready from late spring into early summer. Spring plantings are ready from mid-summer into early autumn. Do not leave them until the bulbs have split open, or they will not store as long.
Dry the bulbs in a single layer somewhere airy, out of very high heat. A greenhouse or a shed is fine. Initial drying takes two to four weeks. Softneck garlic stores longer than hardneck, which the RHS puts at about four to six months.
The bulb did not get enough cold. Autumn planting, or a variety sold for spring, is the way to avoid a lone round clove. Elephant garlic, which is closer to a leek, is also more likely to stay as one clove if it is planted late. The RHS suggests October for that one.
Garlic gets the same rust as leeks and onions: bright orange spots on the leaves. It is worse if the foliage stays wet. Rot is a drainage problem. On heavy soil, use modules rather than a wet winter bed.
Green cloves usually mean the planting was too shallow. They are edible but store poorly. Bulbs that open up were usually lifted too late.
Kit for this crop, based on the method above.
Dug or mulched in before planting. Do not use fresh manure.
For crops started under cover. Deep pots suit peas, beans and sweetcorn.
For pots, modules and containers once seedlings need more body.
For early sowings and for covering tender plants if a late frost is forecast.
Birds pull up new garlic and onion sets, and they take strawberries and sweetcorn.
For lifting roots and potatoes without spearing the crop.
Not if the variety is meant for it. The main season is mid-autumn to early winter, because most garlic needs a cold period to form a bulb. Suppliers also sell varieties for late winter and early spring, and those are the ones to use if you are planting after Christmas.
Softneck. The RHS says hardneck garlic stores for about four to six months, while softneck can keep much longer, potentially towards a year if it was autumn-planted and dried properly.