Cool Weather Vegetable Crops: Facts and Planting

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Cool Season Vegetable Crops: Facts and Planting

by Gary Pilarchik

A  Mix of Cool Weather Vegetables: The Rusted Garden

What Makes A  Vegetable a Cool Weather Vegetable?
The cell structures of vegetables differ in that some vegetables have plant cells that will burst if they freeze or get frosted. Cool weather vegetables tend to have the ability to freeze without celldamage. They are designed for the cooler temperatures.

Fully Frozen and Survived: The Rusted Garden

Cool season vegetables prefer the cooler weather. This group of vegetables grows best and tastes their best with 40-50 degree (F) nights and 60-70 degree (F) days. Cool weather vegetables can bebroken into two sub-categories which are Hardy and Semi-Hardy.


Why Can’t I Plant Them When It Is Hot??
Many of the cool weather vegetables try and set seed when it gets warm. Lettuces, for example, don’t mature to full heads and grow quickly to flower and set seeds when the warmth comes. This is aprocess called ‘bolting’. Most lettuces will also become bitter tasting when it is get regularly warm.


Radishes become woody and also ‘bolt’. The cool weather allows vegetables time to mature slowly and it inhibits (slows) the ‘bolting’ process. Kale is a hardy cool weather crop that tastes sweeter when‘cool grown’ but it can be grown through the whole season in many locations.


Hardy Cool Weather Vegetables: This group of vegetables can manage with 40 degree days and can survive a good frost or two. Many vegetables in this group can over-winter in your garden and bring you early spring greens. Vegetables in this group can be planted up to 4 weeks before the average last frost date in your area. You can probably even get away with 6 weeks if you like pushing garden limits.


Semi-Hardy Cool Weather Vegetables: This group of vegetables doesn’t fare as well with frost although they can handle a light frosting with minimal damage. They prefer day time temperatures in the 50’s and nights that don’t fall below 40 degrees, although they can handle the cold 30’s. Vegetables in this group can be planted up to 2 weeks before the average last frost date in your area.


A Cool Weather Tip
In places with warm to hot summers, you actually have two cool weather seasons. I plant in Maryland Zone 7. I can start my cool weather planting March 1st and I can plant them again mid August for a fall cool season. I actually plant at this time to also establish vegetables that I will let over-winter.


Different Types of Cool Weather Vegetables

The exact split, between hardy (H) and semi-hardy (SH), and where to place a vegetable in the sub-categories is debated. It is best used for general planting guidelines and understanding they simply like the cool weather. My guidelines for each vegetable is based on my growing area (Zone 7). I am giving you the general range for first planting of these vegetables. You can plant successive crops every 2 weeks as you wish based on you planting zone.

Some Cool Weather Vegetable Crops: The Rusted Garden

Asparagus (H) (Perennial) It takes about 3 years to establish a viable crop. It is a perennial plant that will start sending up stalks in March when planted the previous year. If you are planting it for the first time to establish it your garden, it is best to use transplants. You can grow them from seed in cell trays. They should be planting in the garden in May.


Arugula (SH) It can be started indoors and planted in the garden 2 weeks before last frost date. You can also plant seeds at the same time.


Beets (SH) It can be planted as seeds 2 weeks before last frost date. I have had success growing transplants.


Bok Choy (Pak Choi) (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Broccoli (H) It is best planted as a transplant 4 weeks before last frost date. I would not recommend starting it as seeds in the ground in Zone 7.


Brussels sprouts (SH) It is best planted as a transplant 2 weeks before last frost date. I would not recommend starting it as seeds in the ground in Zone 7.


Cabbage (H) It is best planted as a transplant 4 weeks before last frost date. I would not recommend starting it as seeds in the ground in Zone 7.


Carrots (SH) Carrots should not be grown as transplants. They can be seeded in your garden 2-4 weeks before last frost date.


Cauliflower (H) It is best planted as a transplant 2-4 weeks before last frost date. I would not recommend starting it as seeds in the ground in Zone 7.


Celery (SH) It is best planted as a transplant 2 weeks before last frost date. I would not recommend starting it as seeds in the ground in Zone 7.


Cilantro (SH) It can be planted as seeds directly in the garden 2-4 weeks before last frost date.


Collard Greens (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Fennel (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Kale (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Kohlrabi (H) It can be started indoors and planted in the garden 2 weeks before last frost date. You can also plant seeds at the same time.


Lettuce (H) It can be started indoors and planted in the garden 4 weeks before last frost date. You can also plant seeds at the same time.


Mustard Greens (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Onions (H) If you are using bulbs you can plant them 6 weeks before last frost date. I have not used seeds.


Parsley (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Peas (H) They should be planted directly in the ground 4 weeks before last frost date. Peas do not like soggy cold soil.


Potatoes (SH) They should be planted directly in the ground 4 weeks before last frost date.


Radishes (H) They should be planted directly in the ground 4 weeks before last frost date.


Spinach (H) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Chard (SH) It can be planted as seeds directly in the garden 2-4 weeks before last frost date. I do recommend growing it indoors and transplanting it into the garden 2-4 weeks before last frost date.


Turnips (H) They should be planted directly in the ground 4 weeks before last frost date

More Cool Weather Vegetable Crops: The Rusted Garden

Please let me know what other cool weather vegetables I missed. I would be glad to add them to the list.