How And When To Harvest Onions

Knowing how and when to harvest onions is the final, crucial step to enjoying your homegrown crop. Get it right, and you’ll have firm, flavorful bulbs that store for months. Get it wrong, and you might end up with soft onions that rot quickly. This guide gives you the clear signs and simple techniques for a perfect harvest every time.

The timing isn’t a fixed date on the calendar. It depends on the type of onion you planted and what you see happening in your garden. Paying attention to your plants is the best strategy.

Signs Your Onions Are Ready for Harvest

Onions send clear signals when they’re done growing. Look for these three key indicators:

Neck Softening: The area where the leaves meet the bulb (the neck) will start to feel soft and lose its rigidity.
Foliage Toppling: About half to three-quarters of the green tops will yellow, brown, and flop over. This is the plant directing its final energy into bulbing up.
Papery Skin: The outer skin of the bulb begins to develop a dry, papery texture. You might even see it start to glisten in the sun.

When most of your crop shows these signs, it’s time to think about harvesting. Don’t wait for every single top to fall over, as some varieties are more stubborn than others.

The Two-Stage Harvest: A Crucial Technique

For the best storage onions, the harvest is a two-part process: lifting and then curing.

Step 1: Lifting the Bulbs

Choose a dry, sunny day if possible. Wet soil can complicate things and lead to rot later.

Gently loosen the soil around each bulb with a garden fork, being careful not to pierce them. Insert the fork a few inches away from the bulb and lever it up.
Lift the onions out of the ground. Avoid pulling hard by the stems, as this can damage the neck.
Shake off any loose, clumpy soil, but don’t wash them or remove the outer papery layers.

Step 2: Curing for Long-Term Storage

Curing is the process of drying the onions to seal the neck and outer skin. This is non-negotiable for storage success.

Location: Lay them out in a single layer in a warm, dry, well-ventilated spot. A covered porch, garage, or greenhouse is ideal. Avoid direct, harsh sunlight which can actually scald them.
Method: Spread them on a screen, rack, or even on the dry ground. Good air circulation on all sides is key.
Duration: Let them cure for about two to three weeks. The process is complete when the necks are completely tight and dry, and the outer skins rustle like paper.

Special Cases: Green Onions and Thick-Necked Onions

Not all onions follow the main rules. Here’s what to do with these exceptions.

Green Onions (Scallions): These are harvested young, well before they form a bulb. Simply pull them as you need them in the kitchen. Their window of harvest is wide and flexible.

Onions with Thick, Green Necks: Sometimes, an onion’s top refuses to fall over. If the rest of the crop is ready, you can encourage it. Gently bend the tops over horizontally or use the back of a rake to press them down. This stops growth and starts the curing process on the plant. Harvest them about a week later.

Common Harvesting Mistakes to Avoid

A few simple errors can ruin your hard work. Steer clear of these pitfalls.

Harvesting Too Early: Bulbs harvested before maturity have thick, moist necks and won’t cure properly. They’re best used quickly.
Harvesting Too Late: Overly mature bulbs, especially in wet conditions, may start to rot in the ground or develop secondary root growth.
Bruising the Bulbs: Rough handling during lifting causes bruises that lead to spoilage in storage. Be gentle.
Skipping the Cure: Putting uncured onions into storage is a recipe for mold and mush. Patience here pays off.

After the Cure: Trimming and Storing Your Onions

Once cured, your onions need a little prep for their long rest.

Trim the roots off close to the bulb with sharp scissors or pruners.
Cut the dried tops down to about 1-2 inches above the bulb. You can also braid the tops if they are still flexible enough.
Sort your onions. Use any with thick necks, soft spots, or damage first, as they won’t store well.

For storage, choose a cool, dark, and dry place with good air flow. A basement, cellar, or unheated garage often works well. Mesh bags, woven baskets, or slatted crates are perfect containers. Check them every few weeks and remove any that show signs of softening.

FAQ: Your Onion Harvest Questions Answered

What happens if you leave onions in the ground too long?

If left in damp soil, they can rot. In general, they may become over-mature, the outer skin can split, or they might even start growing again, which ruins them for storage.

Can you eat onions right after harvest?

Absolutely! Fresh, uncured onions are often juicier and more pungent. They are perfectly edible but should be used within a week or two as they lack the protective dry skin for long keeping.

How long do cured onions last in storage?

Properly cured and stored onions can last from 6 to 12 months, depending on the variety. Good storage conditions are just as important as the harvest technique.

Should you water onions before harvesting?

No. Stop watering once the tops begin to yellow and fall over. This helps the bulbs firm up and the outer skins start to dry, preparing them for the curing process.

Can you harvest onions after a rain?

It’s not ideal. If you must, let them dry on the soil surface for a day or two before moving them to cure. Wet bulbs are much more suseptible to fungal and bacterial issues during curing.

Mastering how and when to harvest onions is a satisfying conclusion to your growing season. By watching for the plant’s natural cues and following the simple steps for lifting and curing, you’ll ensure a bountiful, long-lasting supply of homegrown onions. Your patience and care will be rewarded every time you reach for a firm, flavorful bulb from your storage.