Why Is My Garlic Bulb Small?

You wait the better part of a year for garlic, dig it up, and find disappointingly small bulbs. It is one of the most common garlic letdowns, and the good news is that bulb size is the sum of several manageable factors — get them right and you grow fat, generous heads. Small bulbs are almost always telling you about planting time, spacing, feeding, or the cloves you started with. Let me run through the key levers.

Planting time and the cold requirement

The biggest factor is planting at the right time so the garlic gets a long enough growing season and the cold it needs. Garlic planted too late (or in spring, missing the winter cold) has less time to build a big plant and may not vernalise properly, giving small bulbs. Autumn planting, several weeks before hard cold, lets the cloves root down and then grow a large plant through spring that bulbs up fat. The longer the leafy growth period before bulbing, the bigger the bulb — which is why timing matters so much.

Spacing and weed competition

Crowded garlic makes small bulbs. Planted too close, the plants compete and none size up, so give cloves proper spacing — around 15 cm apart. Weeds are an even bigger thief: garlic has sparse, upright foliage and competes poorly with weeds, which steal the water and nutrients the bulb needs. A weedy bed is a classic cause of small garlic. Keep the bed scrupulously weed-free all season, and the bulbs have the resources to grow large.

Feeding and water

Garlic needs good nutrition and steady moisture during its leafy growth in spring to build big bulbs — each leaf corresponds to a bulb wrapper, so strong leafy growth means a bigger bulb. Feed with nitrogen in early spring to drive that growth, and keep the soil evenly moist during active growth, then ease off water as the bulb matures. Poor, hungry soil or drought during spring growth gives small bulbs. Then stop feeding and watering as harvest approaches so the bulb finishes and cures well.

Start with big cloves

Bulb size starts with clove size: big cloves grow big bulbs, small cloves grow small ones. So plant only the largest, plumpest cloves from the outside of a good bulb, and use the small inner cloves in the kitchen rather than planting them. Starting with quality seed garlic of a variety suited to your climate also matters. Put it together — plant good big cloves in autumn, space them well, keep the bed weed-free, feed and water through spring growth, and let them mature — and your garlic will size up into the big bulbs you were hoping for.