Why Did My Garlic Split Through the Wrapper?

You dig up your garlic and find the bulbs have burst their papery wrappers, with the cloves splaying apart or the skin split open. Split bulbs are a quality problem — they do not store well and let in dirt and rot — and the cause is almost always one simple thing: the garlic was left in the ground a little too long. Let me explain and help you time the harvest right.

The cause: over-mature in the ground

Garlic bulbs split when they are left in the soil past their proper harvest point. As the bulb over-matures, the wrapper skins that hold the cloves together break down and the cloves swell and push apart, bursting through the protective wrappers. Once those wrappers are broken, the bulb cannot be stored well — it dries out, lets in soil and moisture, and is prone to rot. So split bulbs are essentially a harvest-timing problem: the garlic was ready earlier and stayed in too long.

Knowing when to harvest

The art is lifting garlic at the right moment. The classic signal is the leaves: harvest when the lower few leaves have yellowed and browned but several upper leaves (around five or six) are still green. Each green leaf corresponds to an intact wrapper layer on the bulb, so harvesting while some leaves are still green ensures the bulb has good protective wrappers and has not yet started to split. If you wait until all the leaves have died down, as you might with onions, the garlic is over-mature and the wrappers degrade — which is exactly what causes splitting. Garlic is harvested earlier in its dieback than onions.

Check before lifting the whole crop

Because timing is critical and varies with season and variety, dig up one or two test bulbs as the lower leaves start to brown, and check them: a good bulb is plump, well-divided, with intact tight wrappers. If the wrappers are still sound and the cloves well-formed, harvest the crop; if you see the wrappers starting to loosen or split, harvest immediately, as it is on the edge of over-maturity. This test-dig habit prevents both harvesting too early (small, poorly wrapped bulbs) and too late (split bulbs).

Using split bulbs and harvesting well

Split bulbs are still perfectly edible — use them fresh promptly, since they will not keep. To avoid splitting next time: watch the leaves, test-dig as the lower leaves brown, and lift the crop while several upper leaves are still green and the wrappers are intact. Then cure the bulbs properly in a warm, airy place. Good harvest timing gives you tight, well-wrapped bulbs that store for months instead of split ones that must be used at once.