Organic Onion Transplant Growing Guide

When your transplants arrive, promptly open up box. Unpack them and store them in a cool, dry place until it is time to plant. You can lay them out on a paper towel spreading them out so they do not touch, this deters moldy build-up. Do not worry that your plants seem dry. They will “shoot” new roots and new, green tops as soon as they are planted.

Onions demand light, loose soil and do their best in sandy loam. Amend heavier ground with compost or manure. This is usually best done the previous autumn. The important thing is to encourage them to grow tops as rapidly as possible. This means lots of fertilizer early on. Onions have coarse, small root systems. So place the fertilizer close to the plants and side-dress and/or foliar feed them. Once bulbing begins there is no point in fertilizing them anymore; the bulb’s size is already determined by the size of the top.

Onions have small, inefficient root system and need moist soil. Keep them constantly well-watered. But when the plants approach maturity their bulbs stop enlarging and begin to form skins. When this happens, withhold further irrigation and hope it does not rain much. Ideally, the bulbs will mature in very dry soil. This helps the skins to cure and makes your bulbs keep better. 

After most of the tops have “gone down,” lift the bulbs. It may help to gently loosen them with a shovel first. Allow them to lie in the sun for a day or so, then cure and store them like garlic bulbs or shallots.