Have you tried growing onions yet? Growing onions in Dallas is easy with a bit of preparation. Here are the most frequently asked questions I get about growing onions:
Q: Why aren’t my onions bulbing?
A: Onions fail to bulb for two reasons: it’s too early in the season or the onion variety selected is wrong for the area. Dallas gardeners can grow short-day and intermediate-day onions.
Short-day onions begin bulbing when daylight reaches 10-12 hours. Intermediate-day onions begin bulbing when daylight reaches 12-14 hours. If you accidentally plant long-day onions, the onions will never start to bulb because long-day onions require 14-16 hours of daylight. Here in North Texas our longest day of the year is only 13.5 hours.
Dixondale Farms is my preferred source for short-day and intermediate-day onion plants.
Q: Why are my onions turning yellow?
A: Onions will turn yellow due to overwatering or a lack of nitrogen. To prevent overwatering, only water when the soil is dry up to your first knuckle. To prevent nitrogen deficiencies, apply a balanced
Q: Why are my onion bulbs so small?
The number of leaves on an onion plant when it starts to bulb will determine the final size of the bulb. More leaves, bigger bulb. The top two reasons onion bulbs are small are:
- Onions were planted too late. The longer onion plants are in the ground before bulbing starts, the more time they have to grow leaves. Here in North Texas, I plant my onions in late January.
- Onions weren’t fertilized enough. As previously mentioned, a deficiency of nitrogen can make onions turn yellow, but it also reduces leaf growth. To grow as many leaves as possible, onions need to be fertilized consistently during growing with a high-nitrogen
fertilizer . - Onions didn’t get enough sun. Always plant onions in full sun locations. Onions planted in part-shade to shady locations won’t grow enough leaves to support large bulbs.
Q: How do I know when my onions are ready to harvest?
Harvest onions in Dallas when the tops begin to yellow and flop over. When finally flopped, the tops of the onions will be at a 90-degree angle to the bulb. Still unsure? Squeeze the neck of the onion. It should be soft.
Q: How do I cure my onions?
Onions must be cured unless they are used right away. There are a number of ways to cure onions, but here is the method that works best for my Dallas garden:
- Pull onions and let dry in the sun for 4-6 hours to remove all traces of water. If it is a particularly hot and sunny day, shade the bulbs with the onion tops. (Note: You might have read that onions should lie in the garden for 1-2 days after pulling. Beware that I left my onions in the garden for two days to test this theory, and my onions COOKED in their skins. In our warm climate, onions will dry just fine indoors. Better safe than sorry.)
- Once onions are dry move into a protected area that is well-ventilated. I move my onions into my attached garage once they are dry. I spread them out on mesh screens in a single layer. An oscillating
fan provides good air-flow. Some gardeners leave onions to cure on a covered porch. - Leave for 3-4 weeks until onions are fully cured. Curing time will vary depending on the temperature in your protected location. Keep an eye on them.
Q: How do I know when my onions are fully cured?
Onions are fully cured when the necks are tight and dry. Once cured, cut off roots and trim necks down to within 1″ of the bulb. Onions store best at 32 degrees, but if you don’t have a cold storage option, leave them in a dark, cool area of your home. Store in mesh bags or boxes with holes.
Learn more about growing onions in Dallas and beyond with:
The Complete Guide to Growing Onions in North Texas
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