If you live in N. Texas, now through the end of January is the time to plant your onion sets and slips! Good onion production relys heavily on both soil temperature and day-length after emerging so it's crucial to plant them on schedule. In our region, you need to plant Short-day type varieties (in case you've been flipping through seed catalogs).
Plant your slips about 4-5" apart and about 3-4" deep (don't bury the green portion). Onion sets (bulblets) can be planted the same distance apart and about 2" deep. Onions are traditionally heavy Nitrogen feeders so about 3 weeks after planting (when you see green tops emerging from the sets) start feeding with a good veggie fertilizer. Sidedress your onions about every 2-3 weeks. When tops start to yellow in late spring, stop feeding and watering. Let the tops start to die down...and about 2-3 weeks later you'll harvest your onions.
Onions then need to "cure", after harvest which basically means to dry/harden off. You can of course use your freshly harvested onions in the kitchen for cooking, but if you plan to store them you need to cure them for 2-3 weeks before you bring them indoors or put them in a refrigerator. You can simply lay them out in flats in a dry covered area. The bulb will pull the remaining nutrients out of the top green foliage, which will turn completely brown and the neck will harden. At this point, you can cut off the tops and store your onions in mesh onion bags.
Visit your local independent garden centter for more growing information and to buy your slips/sets, pronto!
So sorry I missed this comment. Unfortunately, I've not seen any available in our area. Best bed would be starting them by seed.
Posted by: Leslie Finical Halleck | February 04, 2012 at 01:16 PM
Do you know where I can get some Potato Onions (aka Multiplier onions)? http://en.wikipedia.org/wiki/Potato_onion
Posted by: Stuart | January 06, 2012 at 01:34 PM