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Cool and Warm Season Crops: Spring Picks

Springtime in the garden is dynamic and full of transitions! The days continue to lengthen and the soil and air temperatures are gradually beginning to warm. You may find yourself wondering if it is too late to seed some crops, and if it is too early to plant other vegetables. A helpful way to think about your choices is to learn if you are planting a cool season or a warm season crop.

Cool season crops are the ones we typically plant on the bookends of the year, in the spring and in the fall. On the other hand, warm season crops are the ones we often plant in mid-late spring for a summer harvest. Here are a few notes that may help you decide when to plant different crops.

Cool Season Crops…

  • can get started growing when ambient temperatures are fairly low, about 40-60°.
  • can also grow when temperatures are warmer (especially heat-tolerant varieties), but will thrive when it is still moderately cool outside or in the shade during warmer summer months. 
  • include leafy greens (such as lettuce, spinach, mustards, chard, kale), peas, cilantro and many roots (such as beets, carrots, radishes).

Warm Season Crops…

  • need warmer ambient temperatures, about 60° or higher, to grow and they need even warmer temperatures to develop and ripen their fruits.
  • cannot grow when temperatures are too cool. If planted too early, they may experience shock or failure to thrive, and if planted too late, they may not have enough time to fully mature. 
  • include fruiting vegetables such as tomatoes, beans, cucumbers, peppers, corn, eggplant and squash.
  • Are typically planted out in the garden in May and June.

In spring, most cool season crops are typically planted March through May, and warm season crops are planted in May and June. However, every year is a little different. During a wet spring, you may be waiting for windows of dry weather to get out in the garden to sow your cool season seeds. During a warm and dry spring, you may decide to plant your warm season crops out as early as possible. However, during a cool spring, you may decide to delay your warm season crops until the weather warms — or you might add some kind of season extension device, such as a cloche covering to warm your plants while the temperatures are low.

As you are journeying through this transitional time of year, consider not only the date in the calendar but also pay careful attention to the weather and how long it will take for that crop to mature. Short-season varieties are ready to harvest in 65 days or less, and long season varieties can take 90 or more days to mature. Keep good notes about what you are growing, and the weather conditions that you are growing them in. Have fun!