How do I grow onions and garlic?
Planting from sets and cloves, the cold period garlic needs, and drying the crop so it stores.
- Difficulty
- beginner
- Time
- 1 hr
- Read
- 2 min
Short answer
Plant garlic in autumn — it needs a cold period to form bulbs — and onion sets in autumn or early spring. Both need sun, free-draining soil and no competition from weeds, and both must be dried properly to store.
Onions and garlic are among the easiest crops and among the most rewarding to store. The two things that matter are the timing of planting and drying the harvest thoroughly, which determines whether they keep for months or rot in weeks.
What you'll need
- Onion sets or garlic bulbs
- Sunny well-drained bed
- Netting against birds (optional)
Step by step
- Plant garlic in autumn.It needs several weeks below about 10°C to split into cloves. Spring-planted garlic often produces a single undivided bulb.
- Use bulbs sold for planting, not supermarket garlic.Culinary garlic may be treated to prevent sprouting and is often a variety unsuited to your climate.
- Plant cloves pointed end up, 15cm apart, 5cm deep.Split the bulb just before planting. Deeper in light soil, shallower in heavy soil.
- Plant onion sets with the tip just showing.Autumn or early spring depending on the variety. Firm them in, and check after a few days — birds pull them out and they need pushing back.
- Choose a sunny spot with free-draining soil.Both dislike sitting wet. On heavy soil, plant into a raised ridge or a raised bed.
- Keep them weed free.Both compete poorly with weeds because their foliage is sparse. Hand weeding or a shallow hoe, carefully, since the roots are near the surface.
- Stop watering as the foliage yellows.They are finishing and ripening. Continued watering at that stage encourages rot in storage.
- Lift when the foliage flops, then dry thoroughly.Lift on a dry day and dry in an airy place for two to three weeks until the necks are papery. This step determines whether they store.
Tips
- Garlic scapes — the flower stems on hardneck varieties — should be removed to direct energy into the bulb, and they are excellent to eat.
- Do not store onions with soft or thick necks. Use those first; they will not keep.
- Rotate alliums around the garden. White rot persists in soil for many years once established.
Common mistakes
- Planting garlic in spring — It needs a cold period to split into cloves. Spring planting commonly gives a single round bulb instead.
- Not drying the harvest properly — Bulbs stored before the necks are papery rot within weeks. Two to three weeks in an airy place is the difference between months of storage and none.
- Planting supermarket garlic — It may be treated to suppress sprouting and is often a variety unsuited to the local climate.
Questions people ask
When should I plant garlic?
Autumn, so it experiences several weeks of cold. That cold period is what makes the bulb split into cloves — spring-planted garlic often produces a single round bulb.
How do I store onions and garlic?
Dry them for two to three weeks after lifting, until the necks are papery, then keep them somewhere cool, dark and airy. Use any with soft or thick necks first.