Should onions be harvested immediately when tops fall over?
Written by
Benjamin Miller
Reviewed by
Prof. Charles Hartman, Ph.D.Don't resist harvesting onions just because the tops are falling over - they need another 7/10 days before they should be harvested. In that time, they will have grown an additional twenty-five percent in size, the protective scales will have formed properly, and the necks will close naturally - no thick necks that retain moisture and cause rotting.
Bulb Expansion
- Carbohydrates transfer from foliage to bulb
- Diameter increases significantly
- Firmness develops fully
Neck Transformation
- Stems dry from fleshy to papery texture
- Forms natural seal against moisture
- Prevents pathogen entry during storage
Skin Development
- Outer layers form protective papery coating
- Color intensifies in red and yellow varieties
- Creates barrier against bruising
Immediate harvesting causes thick necks that trap moisture and promote the growth of rot fungi; bulbs lack protective scales. I learned this when half of my early harvest of onions went bad due to mold. I mark the fallover dates religiously on my calendar. Patience gives you over-winterable onions.
Watch your bulbs daily while they lie in the waiting phase. Test the neck for flexibility with the roll test described above. Protect from rain with row covers, if necessary, and make sure the earth underneath is kept completely dry. The roots must shrivel, natural-like, for no new growth is desired: this takes sugar.
The longer you keep an onion, the more valuable your onion. When onions are stored correctly, they will store until at least the spring months. They will caramelize much better when cooked. You will also not have the unfortunate experience of rotten onions. For the best possible harvesting experience, follow these recommendations.
Read the full article: When to Harvest Onions: Ultimate Guide
