Did you know that some vegetables thrive in cool weather and really won’t do well in the summer heat? Cool season vegetables love to grow in the cool of spring and fall.
Understanding the difference between Cool Season Vegetables and Warm Season Vegetables is very important. This is something that many new gardeners don’t understand, and it leads to some frustrations and problems.
Cool season veggies prefer to grow in temperatures that are at least 15 degrees below those preferred by warm season crops. Most cool season vegetables do best when the temperatures are in the 70s (20 to 26° Celsius). Warmer temperatures, those above 80 degrees (26° Celsius) will start to affect the quality of the plant. Warm temperatures are a signal for cool season vegetables to bolt (start producing seeds). This will cause most cool season vegetables to become bitter and have a tougher texture.
Most cool season veggies are grown for their leaves (lettuces), immature flowers (broccoli), roots (carrots) or in one case seeds (peas). The cool temperatures enhance the flavor and texture of these plants.
Frost is Okay for Cool Season Vegetables
Cool season crops can also withstand brief periods of frost at night and most will continue to do well when temperatures at night drop into the 30s (0° to 5° Celsius). In fact, frost will actually improve the flavor of many cool season vegetables like broccoli, spinach, kale, and even carrots.
If your weather forecast predicts some extended periods of frost you might consider protecting your crops from that frost. Fabric row covers placed on your plants in the evening and removed during the day will do a great job at keeping frost damage at bay.
Plant in Spring & Fall
One thing to keep in mind is that unlike their warm season cousins cool season veggies can be planted twice. There are two growing seasons for cool season crops, spring and fall. You can start most cool season crops 4 to 6 weeks before your last frost in the spring and you can plant them again 6 to 8 weeks before you first frost in the fall.
Many cool season vegetables can even grow during the winter months if you offer them protection from a hoop house or cold frame. You can learn more about winter gardening from this series I wrote on the topic.
Complete List of Cool Season Vegetables
- Garlic (Plant in the Fall)
- Bunching Onions
- Arugula (Rocket)
- Swiss Chard
- Mustard Greens
- Asian Greens
- Pak choi (Bok choy)
- Tot Soy
Cabbage Family Crops
- Brussels Sprouts
- Sprouting Broccoli
- Celery and Celeriac
What is a cool season vegetable?
Cool season vegetables are crops that grow better in the cool times of the year. Most prefer to grow in temperatures under 75 degrees. Examples include lettuce, onions, carrots, broccoli, and cabbage.
What are some cool weather crops?
Examples of cool weather crops include leafy greens (lettuce, spinach, Swiss chard), root crops (carrots, radishes, turnips) and cabbage family crops (broccoli, cabbage, cauliflower).
Is 40 degrees too cold for vegetable plants?
Night time temperatures of 40 degrees will be fine for most cool season crops, but if your daytime temperatures are around 40 degrees then you will find it hard to grow even cool season crops because nighttime temperatures will be well below freezing.
What temperature is too cold for vegetables?
The hardiest of the cool season vegetables will hold up to temperatures at or slightly below freezing (32° F, 0° C). But if your temperatures are going to be much colder than freezing for several nights in a row you should protect your vegetables with fabric row covers or a cold frame.
Which plants grow in cold climates?
Cool season vegetables like lettuce, broccoli, carrots and many more will grow well in the late spring and summer in cold climates.
Gardening isn’t just for the summer time! These cool season crops will grow well in cooler temperatures and extend your harvest into the spring and fall! Which of these crops will you be trying out this year?