When to plant vegetables

March 18, 2011

My NCAA men’s tournament bracket choices are showing to be less than stellar.  The sun is shining and I am itching to plant garden vegetables. I just can’t plant through the snow that is still covering my garden spot.  When is the appropriate time to plant?  Below is my personal guide with my reasons.

Early crops

Onions, peas, radishes, and most cole crops can be planted very early.  They are very hardy and can withstand a frost.  Many of these plants have inherent tolerance to light frosts.  Potatoes will freeze but they will regenerate if frostbitten and continue to grow well.  Transplanted crops like broccoli and cabbage must be acclimatized to cold weather or they will freeze.  I planted potatoes on March 17 in OH and was eating small potatoes in mid June.  I will plant the above crops as soon as I can reasonably till the soil and get the seed in without having to plant in mud.

Mid season crops

Several vegetables grow quite well in cool weather but can’t be frozen.  These are carrots, lettuce, sweet corn, red beets, swiss chard, and sometimes tomatoes and beans.  Some crops like beans can be seeded before frost ends but they germinate very slowly in cold weather and may not emerge until the threat of frost is over.  The difference is they take 3 weeks to germinate in cold weather but can germinate and emerge in 5 days in warm weather.  Sweet corn and garden peas have growing points that stay below the soil for a long time and can regenerate the plant if it freezes.  Still, any frost isn’t really good for the plant.

Late season crops

Many people would put tomatoes with this group along with sweet potatoes, okra, all melons, cucumbers, squash, pumpkins, and beans also fall into this category.  If a seed grows by pushing the seed up and the two parts of the seed become the two first leaves, it is probably a late season crop.  The growing point is above the soil line and may freeze easily. 

Most seeds, if planted very late in the fal,l would germinate and grow based on when the soil temperature is right.  The soil temperature corresponds to the season and often will allow the crop to either avoid frosts or the crop will be able to tolerate a light frost.  Vegetables that can’t tolerate frost will germinate late enough that they usually don’t emerge until after the threat of frost is over. 

Early crops grow rapidly in cool temperatures and continue to grow well in warm weather.  Late season crops stagnate in cool temperatures and grow very rapidly in warm weather.  In fact, corn in hot humid weather can grow so fast you can hear squeaking as the expanding leaves slide by the other leaves coming out of the whorl.

My plans are well laid in my head, may yours be also.