When to sow:
warm temperate areas - generally speaking, it can be planted in autumn through to early winter. Under warm temperate climatic conditions autumn planted garlic will remain dormant for a few weeks, then develop roots and a shoot. With the onset of the cold of winter growth is fairly slow until temperatures warm in
spring. The cold of winter is needed to initiate the side buds that will ultimately grow and swell to become cloves (and in some types, to initiate the
flower bud). The lengthening days of
spring are the signal for the initiated but undeveloped side buds to start forming into cloves. It is possible to sow in early
spring and get a reasonably good harvest, but everything is against you - wet, difficult to work soil; no early root growth; less exposure to winter chill. Early
spring is possible, but definitely a second choice.
Temperate areas-
plant after the first good frosts of autumn.
spring planting is possible in the higher latitudes, as the longer day lengths promote bulbing, but the shorter season means the bulbs are often smaller. Autumn garlic will produce roots, but either no, or short, top growth. If the garlic sprouts have emerged, they will survive freezes and snowfalls, but they should be mulched heavily (about 15 cm/6 inches) to prevent heaving. Pull the mulch aside in
spring. Autumn planted garlic will have strong roots by winters icy grip, and these roots will help prevent the '
seed' being pushed out of the ground as the soil alternately freezes and thaws ('frost heave').
How to sow:
Choose the biggest and fattest
seed cloves, and sow them root end down, standing erect, and far enough in the soil that they are anything from just buried to being 25 mm/an inch or so under the soil surface. Put them about 100 mm/4 inches apart.
Harvesting:
The
plants are ready to harvest when the foliage has died off, or mostly died off. If it is very wet near harvest time, consider lifting them a bit earlier and drying them under cover. Left in wet soil, the outer parchment often rots. And if there is disease in the root plate, it may develop too far and cause the bulb to fall apart when it is lifted.