The growing season has started for some plants. I get lots of questions about onions so here is some information that you might find helpful.

Although soil, temperature and water are important when growing onions, hours of daylight is the magic ingredient to growing onions. Roots and foliage start to grow immediately but it isn’t until day length reaches 12-14 hours that the onion bulb starts to grow.

There are 3 onion categories: long-day, short-day and intermediate-day. For our area intermediate types grow the best and should be planted in the early spring. This is established by latitude. The northern states grow long-day types and the southernmost states grow short-day types.

We can grow most onions in Burke County but not all will make bulbs because of the day-length requirements. If you just want green onions, then planting time is not important nor is the type but if you want large bulbs you do need to choose an intermediate day length variety. When purchasing onion seeds, sets or plants be sure they are the intermediate category. Some popular intermediate category onions are:

Calibra-red
Zoey-yellow
Monastrell-red
Cabernet-red
Sierra Blanca-white
Candy-yellow (sweet Walla Walla type)

These are just a few. Many more cultivars are available.