Garlic prefers a light, well-drained soil in full sun, it won’t tolerate wet and heavy soils. If this is your soil you can plant in modules in the autumn and plant out in Spring as the weather improves. Garlic can only be grown from bulbs because viable seed is extremely difficult to produce at present.
There are two types of garlic, ‘hardneck’ and ‘softneck’ referring to the way they grow. The hardneck varieties produce a flower stem known as a scape which can be used in soups, curries and stirfries and has a more delicate flavour than the bulb. The softneck varieties don’t produce a scape but have a longer shelf life.
Garlic needs a cold period to grow successfully so the best time to plant is the autumn though there are spring planting varieties available. The bulb should be carefully split into it’s separate cloves and each clove planted 2.5cm below the surface with the root scar facing down, the clove should be sitting just below the surface. They should be planted 10cm apart in rows that are 30cm apart. Addition of compost at the planting stage will help the soil structure keeping it light and feed the cloves as they grow.
Garlic needs limited maintenance except for keeping it weed free, watering during long dry spells and protection from birds who’ll be tempted to pull the bulbs out of the ground. There are two diseases to look out for which are white spot which will rot the roots and eventually the bulb too and rust which shows up as rusty spots on the leaves. There is no cure for either and you should avoid growing garlic in the same spot for at least 3 years if you have either of these problems. Crop rotation will help to discourage these pathogens.
Autumn planted garlic can be harvested around June or July the following year. You know when it’s ready to harvest when the leaves start to turn yellow, don’t put this job off or you may find the bulb re-sprouts causing it to rot later and thereby reduce its shelf life. Take care when lifting the bulbs out of the ground not to damage them with your trowel as this too will compromise their keeping qualities.