Heat- Versus Cool-Loving Crops

In my simplistic view of vegetable gardening, there are two kinds of crops: heat-loving and cool-loving.  When I say cool-loving, I don't mean winter.  Although I have had Swiss chard and mustard greens that overwintered in the ground, I do not plan on anything making through snow.  The point I am trying to make is that some crops do better in summer's hot temperatures, such as tomatoes, peppers, beans and corn.  Others prefer the cool temperatures of spring and fall, like lettuce, celery, peas, cabbage, spinach, broccoli and cauliflower.  (Broccoli and cauliflower are classified as "Cole crops" which is often mispronounced "Cold crops" because these plants happen to prefer cool weather.)

With this in mind, I view the planting season in two phases, a cool weather phase followed by the warmer summer season.  The planting of seedlings  is staggered, with the cool-loving ones planted indoors as early as February.  Warmer plants are seeded six weeks before May.  The first group should go in the ground 4-8 weeks before the second.  If you have the time and energy, you can repeat the spring crops in the fall.

In our mid-Atlantic region each group of plants has its challenges.  Either can perish in a late snow or frost and may need to be covered at night.  Cold-loving plants that are kept in a greenhouse, hoop house, or cold frame are susceptible to too much heat, even when the outside temperatures are chilly.  Today our hoop house reached 90 degrees by ten o'clock while the outside air was in the low 40s.

How does one deal with excessive greenhouse temperatures?  Open the windows, doors, and vents.  Water the plants early in the morning.  Cover the greenhouse with shade cloth, if available.  The same techniques can be used in the garden to keep your crops going as seasonal temperatures rise.  This is probably a gross oversimplification of things, but thinking in terms of these two groups--cool and warm--has helped me execute my vegetable gardening throughout the year.

Bok Choi in front of artichoke.