Have your crops been VERNALIZED?

Today as the sun shines, in what has been the driest, sunniest most beautiful wind free winter in our 9 years on the northern coast of California, I feel myself wanting to get a jump start on the planting season.

I am reminded however of an incident that took place this past summer, whose beginnings were rooted early in the season last year.

In mid August several farms in our area were lamenting the fact that a large portion of their onion crops were bolting (going to seed) instead of bulbing. A very sad event, unless you love the large globe shaped flowers that ensued. I had remembered reading something about that the previous winter but the particulars had slipped my mind so I rummaged through my stack of books and found the answer to our dilemma.

Frank Tozer in his book “The Vegetable Growers Handbook” states that when onion starts are subjected to temperatures lower than 50 degrees Fahrenheit for 2 consecutive weeks, such as in an unheated greenhouse during an unexpected cold snap (exactly what happened here last spring), and then exposed to warmer temperatures again, the plants think they have gone through a winter and therefore decide it’s time to set seed.

It seems that this problem usually only affects the plants that are 1/4 inch in diameter or larger at the time of the exposure to the cold temperatures. Vernalized defined. Seeding, size and temperature are all important considerations when raising onions.

I bought Frank Tozer’s book after reading a review from a fellow Freshman Farmer a few years ago.  I had always wanted to get my many snippets of growing information organized and in one place. Frank’s book did the job for me. For example six pages are dedicated to ONIONS. Topics covered include an introduction, nutrition content, growing facts, rotations, seeds, sets, sowing, care, problems, harvest, seed saving, a recipe and so much more.  I love this book!

So even though the sun is bright and warm today, I will exercise patience and wait to sow seed for a few more weeks.