Why Is My Garlic Neck Rotting?

You store what looked like a sound bulb, then find it rotting and going soft from the neck down, sometimes with a grey mould. This is neck rot, a fungal disease that mostly shows up in storage and is closely tied to how the garlic was grown, harvested and cured. It is a frustrating way to lose a harvest after the hard work is done, but it is largely preventable. Let me explain.

What neck rot is

Neck rot is caused by a botrytis fungus that infects the neck of the bulb — the point where the leaves meet the bulb. It often gets in during the growing season or at harvest but stays hidden until storage, where the bulb begins to soften and rot from the neck downward, frequently with a grey, fuzzy mould and sometimes small black sclerotia developing. Because it shows up weeks after harvest, growers are often puzzled to find apparently good bulbs rotting in store. It is one of the main reasons garlic fails to keep.

Curing is the key

The biggest factor in neck rot is curing. The neck must be dried thoroughly after harvest so the fungus cannot establish — garlic that is poorly cured, with a damp neck, is highly prone to neck rot in storage. Cure garlic by drying it in a warm, airy, shaded place for a few weeks until the neck and skins are completely dry and papery. Good airflow during curing is essential. Rushing or skipping curing, or curing in damp conditions, is a direct route to neck rot. Proper curing seals the neck and is your main protection.

Growing and harvest factors

Conditions in the garden matter too. Wet weather near harvest, excess nitrogen producing soft growth, and damage to the neck all increase neck rot risk. Harvesting at the right time (not over-mature) and in dry conditions where possible, handling gently to avoid bruising the neck, and not leaving the bulbs in wet soil all help. Using clean, disease-free planting stock reduces the fungus carried over, and rotation limits build-up. Softneck types, which have tighter necks, can be more prone, so curing them especially well matters.

Preventing neck rot

To keep neck rot out of your stored garlic: grow in well-drained soil without excess nitrogen, harvest at the right time in dry conditions, handle gently, and above all cure the bulbs thoroughly in a warm, dry, airy place until the necks are bone dry. Then store cool, dry and airy. Inspect stored garlic and remove any showing softening at the neck before it spreads. With good curing and storage, neck rot becomes rare and your garlic keeps for months as it should.