Why is my garlic small with tiny cloves?

Garlic is one of the few crops where the harvest is decided months before you see it. The bulb is built out of the leaves the plant made in spring, so anything that limits leaf growth between February and May limits the bulb, and by the time you notice in July nothing can be done about it.

Step by step

1. Plant in autumn, not spring.Garlic needs several weeks below about 10°C — vernalisation — to split into cloves at all. Autumn planting gives it that cold naturally and a long root-building period. Spring-planted garlic in the UK routinely produces a single round bulb with no cloves.
2. Use bulbs sold for planting, not supermarket garlic.Culinary garlic is often imported from warmer climates, is not adapted to a British winter, and can carry virus and white rot. Certified planting stock costs more once and performs every year.
3. Plant the largest cloves from the outside of the bulb.Clove size directly influences bulb size. Use the big outer cloves for planting and cook the small inner ones.
4. Space it properly.Roughly 15cm apart in rows about 30cm apart. Garlic crowded at 8cm will grow, but every plant limits every other and you get a row of small bulbs.
5. Keep it absolutely weed free.Garlic has thin upright leaves and no ability to shade out competition. A weedy row is the commonest cause of small bulbs on an allotment. Hoe carefully and often, or mulch.
6. Water through spring if it is dry.The plant builds its leaves from late winter to late spring, and that is when water matters. A dry April costs you bulb size. Stop watering once the foliage begins to yellow.
7. Feed nitrogen early, then stop.A nitrogen feed in late winter and early spring supports leaf growth. Feeding after about May pushes soft growth that stores badly. Nothing after the bulb starts swelling.
8. Remove scapes on hardneck varieties.Hardneck garlic sends up a curling flower stem in early summer. Cutting it out redirects energy into the bulb and is worth a noticeable size difference. The scapes themselves are excellent eating.
9. Do not lift too early.Lifting when the leaves are still mostly green costs you the last and largest increment of growth. Wait until roughly a third to a half of the leaves have yellowed.

Tips

• Every green leaf on a garlic plant corresponds to a wrapper layer on the bulb, so the plant with the most leaves in May makes the biggest bulb in July.
• On heavy wet soil, plant into a ridge or a raised bed. Garlic sitting in winter wet rots or grows poorly.
• Hardneck varieties generally have larger, fewer cloves and better flavour but store less well; softnecks store far longer and are the ones that plait.
• If your autumn planting failed and you are starting in spring, choose a variety sold specifically for spring planting and expect a smaller bulb.
• A single round bulb with no cloves is still perfectly good garlic — use it in the kitchen, or replant it in autumn and it will usually clove up the following year.

Common mistakes

• Planting supermarket garlic in spring — Wrong climate adaptation, wrong timing and no cold period. It is the most common reason for a row of tiny undivided bulbs.
• Leaving weeds because 'it's only garlic' — Garlic competes badly. Weed competition in spring is worth a large fraction of the final bulb size.
• Watering right up to harvest — Late water swells the neck, delays curing and encourages rot in store. Stop as the foliage yellows.
• Planting cloves too shallow — Frost heave lifts them out over winter and the plant never establishes a proper root system. Cover with about 5cm of soil above the tip.

Questions people ask