Tuesday, April 24, 2007

What Does It Mean When Your Onions Start To Bolt?

Failure in onion production comes in two forms - - complete annihilation of the young seedlings during a cold winter or an abundance of spring onion flowers which decrease bulb size, weight and storage ability. Onion plants which are small and rapidly growing when the cold temperatures of winter arrive will probably not survive. Yet, if you plant earlier and the stem of onion plants are larger than a pencil when exposed to cold temperatures, the onion will initiate and produce a flower during the following spring. This flowering is termed bolting. Bolting requires low temperatures. Most rapid bolting is caused by temperatures of 40-45 degrees F. or below. Fall seeded crops are susceptible to bolting the following spring if warm fall temperatures, allowing excessive growth, are followed by low winter temperatures and slowed growth. Many gardeners believe that early removal of the onion flower stalk will cause onion bulb enlargement but this has not proven to be the case. Flowering causes a decrease in bulb size as well as a central flower stalk which enhances decay during storage. This is exactly what will happen to those who are planting onion transplants or sets in October or November with the hope of large onions next spring. The onion bulbs which produce a flower stalk may be large but they will be light-weight (one-half the weight of a comparable size, non-flowered onion bulb) and prone to decay. Obviously, what you see is not always what you get! The best way to insure success is to either plant the onion seed from October 1 until November 15 or plant transplants from January through February in Texas Zones III - V (USDA Zones 8 and 9). Read more here.

Spring onion flower in my garden. At first, I thought these were the "onions".

No comments: