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.
Growing Conditions For Cold Hardy Vegetables
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.
Best time of year to Plant Cold Weather Vegetables
The advantage to cool season vegetables is they can be planted twice! There are two growing seasons for cool season crops, spring and fall. Warm season vegetables like tomatoes, peppers, and cucumbers can only be planted one time in your gardening season.
It is so nice to be able to enjoy cold weather vegetables twice a year. They should be planted in the cool spring season but in early spring before it gets too hot. In early spring you can even warm up the soil to help your seeds germinate better. Learn how to do that in this article here.
The next season to start your cold season vegetables is in the fall. In order for you to get a nice fall harvest, most seeds need to be started in late summer in your garden. You may need to start your own seedlings inside in early summer so they are ready to be planted later in the summer.
When do you plant cool season vegetables?
Your cold hardy vegetables need to be planted early enough so they have enough time to mature and can be harvested before the heat of summer causes them to bolt and go to seed. You can start most cool season crops 4 to 6 weeks before your last frost date in the spring.
Cold weather vegetables can also be planted again in late summer for a nice fall harvest or for more cold hardy vegetables you can harvest through the winter. Look at your seed package to see the days to maturity. They need to be planted early so that the plant is mature enough to either be harvested through the winter or can be harvested in the late fall before winter sets in. This usually is 6 to 8 weeks before your first frost in the fall.
Many cold hardy vegetables can even grow during the winter months if you offer them protection from a hoop house or cold frame. Yes, you read that right you can harvest vegetables all winter. You really can have something fresh from your garden all year!! You can learn more about winter vegetable gardening from this series I wrote on the topic.
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, a light 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.
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 summertime! 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?