So, you want to grow collard greens in the winter.
Did you know the cold is actually good for collard leaves?
You can get sweeter yields and softer foliage from chill time.
But some people that are in colder climates will need to take special precaution.
The timing of the planting matters more than anything else if you’re in zones 6-8.
Collard greens are a biennial plant. But if you’re somewhere cold, it’s only an annual unless you take extreme measures.
Let’s dive in and see what you can do to keep this plant producing the sweetest greens ever.
Do collard greens need winterizing?
Collard greens come in a variety of different species, but the majority of them are considered to be winter hardy.
Therefore, you may not need to stop enjoying the delicious taste of collards during the winter!
Though, don’t get too excited.
It completely depends on your hardiness zone. You may be able to get away with doing absolutely nothing.
And you’ll still be able to enjoy the delicious sweet flavor during the winter.
But if you’re somewhere colder and prone to temperature dips, you may want to do something to protect them.
How to care for collard greens over the winter
Cold temperatures will kill the plant- no matter how cold hardy you think they are.
So yes, some collard greens will need to be winterized during the winter to protect them. Others (most people) won’t have to do anything that is in milder regions.
It completely depends on:
- Your location
- The type of collard you’re growing
A mixture of these two variables determines what you’ll need to do to ensure your plant handles the cold and continues growing those tasty leaves.
Let’s dive in and find out.
Find out your local frost date
This is critical information that you should take note of before you do anything else. Knowing the first and last frost dates of the current season will let you gauge when to winterize your plants.
The point is to sow the seeds early enough so that you can harvest it after a few light touches of frost for that flavor and texture, but not late enough before the first “real” freeze which kills it.
Choosing when to sow the seeds is imperative for a successful harvest. Hopefully, you didn’t throw the seed packet away.
Check your packet for details on the specific type of collar green you’re growing and the days until maturity.
With these two pieces of info, you can figure out when to plant the seeds.
So now you should know:
- The estimated first frost date
- The days until the harvest of your green
- The cultivar (type) of collard green you have
Sow the seeds based on the frost date
The trick is to plant the seeds so that they grow to a full crop before the first frost.
You want them to go through at least one or two light touches of frost so they get some exposure to the cold. Then you want them to continue growing to a harvestable state before the real first frost. Count backward.
For example, if your first frost is estimated to be in 80 days, and your days to maturity is 55 days, then you should plant now.
This will allow your collard greens to fully grow to a harvestable state and it’ll be done before the first frost.
If it’s too early, there’s usually no harm in planting. Though, they won’t be as tasty or tender since they didn’t subject to a light frost or two before you harvested them.
If it’s too late, you shouldn’t risk it.
This is means for killing your plant unless you can provide the right protection for it to sustain the cold winter. If you’re in a mild area, this is OK as even your first frost probably won’t be enough to do any major damage.
But if you’re in a cold zone (6-8), you’ll want to either wait until the frost is over or winterize your plant accordingly.
It’s not always easy to find out what you need to do, but don’t overthink it. Focus on the first frost date and plant as necessary.
Where to plant
If you’re in a temperate area, you can sow your seedlings inside your home and keep them there.
Choose an area that receives about 5 hours of direct sunlight daily. Collard greens aren’t picky about the sun, so there’s no need to blast them with beams of UV light.
They like cold more than heat. That’s what gives them the prime flavor!
When to transplant
Move the collards outside around 8 weeks before your first frost.
The goal is to give them some cold exposure to sweeten their taste and soften their flavor.
This should work for warm locations and depends on your type of collard green and the soil/weather conditions.
Collard greens appreciate watering with well-draining soil.
Their needs are minimal and don’t need to be overdone. Water when the soil gets dry at the first few inches.
Collard greens can benefit from some 10-10-10 fertilizer over the area you wish to plant. Sprinkle some and mix it into the soil within the top 3-4 inches.
They’re not needy so you don’t need to worry too much about it.
Use a high-quality fertilizer if possible- opt for organics since you’ll be eating these greens.
You can use a rake to mix in the fertilizer to your plant plot. 1 cup should be enough for about 10 feet of collard greens, but you should apply as directed by the instructions on the back of the package.
Brassicas are the best tasting after they’ve been exposed to some degree of chill time.
Collard leaves can be harvested when they reach a good size and are the tastiest after 1-2 light touches of frost and when still young.
A good size is around 8 inches and dark green in coloration.
Typically, this is around 85 days if you sow from seed and 75 days from transplants.
Avoid harvesting older leavers which are larger than 10” in size as they’ll be chewy, tough, and stringy to the bite.
Bolted greens are also sub-par in flavor and texture. If you’re picky about your collard leaves and want to only taste the best, let them get some cold and harvest them before they turn.
Should you harvest after bolting?
There’s no harm in harvesting after the plant has bolted, but the flavor is usually bitter.
The leaves also become tough so unless you want a sub-par harvest, you should compost those greens and just start over.
Bolting occurs when the spring comes and the temperatures pick up. They bolt because they’re biennials. This allows them to set seed for future generations of collards.
Again, you can still eat them if you wish. But don’t assume you’ll get the best flavor.
Best types of collard greens for cold temperatures
The hardiest cultivar is the Brassica oleracea var. acephala, which can tolerate temperature dips as low as 20F. This species is also very common and easy to find for cheap.
So if you want to do the least amount of maintenance possible and enjoy your greens all winter long, consider planting this specific variant.
Most gardeners will swear by saying that cold exposure helps improve their taste by helping the plant produce more sugar rather than store plant starch.
You’ll often find greens that have been exposed to a chill period will produce sweeter and tender leaves compared to bitter and chewy foliage.
But even the acephala can’t handle temperature that drops into the low teens. This will kill the plant.
So it’s a fine line between producing the best collard greens you’ve ever tasted or killing the harvest entirely.
Either way, this is a beginner-friendly plant and allows room for mistakes.
Even collard greens that have been completely weathered and frozen can still be harvested, thawed, and cooked for eating!
Does frost damage collard greens?
Frost is good for the flavor of collard leaves, often making them taste sweeter. So frosts are good.
But if you’re somewhere that’s prone to cold snaps, you’ll have to take them indoors or mulch them outdoors.
Those in warmer winters should be fine with leaving them outside, however, the time to plant should be timed so that the leaves are harvested before the first hard frost.
What hardiness zones grow collard greens best?
Collard greens have a wide temperature tolerance and thus do well in different hardiness zones.
They can be grown in zones 6-10 and will overwinter by themselves in most warmer areas.
Mild winters will benefit the texture of the leaves and they don’t require any additional measures to keep them warm.
However, extremely cold hardiness zones or areas known for severe cold snaps will require some protective assistance to help them keep warm.
This is especially true in zones 6 and 7, which can be cold enough to kill the plant.
How to protect collard greens from cold snaps
You can protect your plants from dips in the weather by adding mulch to insulate them. There are many different types of mulch you can use, but straw mulch should be fine.
Add a thick layer around the stem and keep it tidy.
Scrape off any snow that builds upon the mulch surface- do NOT let it sit there. The snow buildup will make it extremely cold under the layer of it.
So you’ll need to remove it every time it snows. Remove the mulch layer entirely after you harvest or when temperatures pick up again in the spring.
You can also add row covers to keep snow out and add another layer of protection against the elements.
Floating row covers are awesome and serve their purpose. This is how people overwinter their collard greens in colder zones like 6.
Should I bring them inside my house in the winter?
This is detrimental to their established systems underground. You should avoid moving your collards indoors to winterize them unless you have them growing in containers.
If they’re grown in soil, avoid moving them and use outdoor protective measures (mulch, row covers, etc.).
But if you grew them in pots or planters, you can move them indoors. It’s important to still give them cold exposure though if you want to get the most flavor possible.
A temperature-controlled environment like your garage can help expose them to cold temps, but not to the point where it kills them.
Cold climate harvesting
There are some things you can do to help your collard greens maximize their texture and flavor.
Winter harvesting is the idea of keeping your greens in the cold as long as possible before you harvest. This will help get them flavorful and on the tender side.
Here are some tips for winter harvesting:
Use cold frames
These help to protect your greens from cold, but allow them to get cold exposure at the same time.
There are plenty of online blueprints you can follow, such as this video:
Cold frames can be made from old window frames or scrap wood.
Use a greenhouse
A greenhouse can regulate the temps and keep them stable. It prevents temperature dips and spikes by elongating the time to heat up or cool down.
Some are temperature controlled so you can set it as you wish.
You can add mulch around the perimeter of your plants to help protect them against the elements. This will add a layer of insulation.
You can use leaves, straw, or even shredded newspaper.
Just be careful about rot and mildew from trapped moisture.
When the snow builds up on top of the mulch, you’ll need to clean it off so it doesn’t kill the plant from the cold temperatures.
Use row covers
You can install basic, cheap, floating row covers to help keep the mulch from blowing away and keep debris out.
These will also help guard the collard greens against some degree of cold and snow exposure. This will help maximize your cold exposure and get you sweeter tasting greens when you harvest them.
Other FAQs about winter growing
Here are some other common FAQs about collard greens.
Do collard greens come back every year?
Collard greens are biennials and known as a “cut and come again vegetable.”
In other words, these are just veggies that are harvested in a different way than most people are used to.
The leaves grow in a “rosette” which means they circulate from the inside out. The new younger leaves come from the center of the stalk with the older ones outside.
You can keep your collards growing all year long if you cut from the outside in. Avoid cutting from the inside of the rosette so you have a continuous supply of leaves during the season.
Protecting through the winter is just one thing you need to do to keep the plant producing.
For those in warmer regions, this plant continues to produce over and over. You can use bolted seeds to plant even more collards if you want.
Colder regions may end up being an annual event.
Warmer regions cause collard greens to bolt. The heated weather makes the leaves start to produce seeds and are often not edible after they bolt because of poor texture.
How cold can collards tolerate?
Most collards are cold hardy and can tolerate temperatures as low as 26F, but not for extended periods.
Temperatures in the low 20s and high teens will burn the foliage and damage the plant.
Some cultivars aren’t made to withstand cold snaps and should be protected during the winter.
Cold hardy types (such as var. Champion ) do well in colder temperatures and handle multiple touches of frost without any problems.
What can you NOT plant near collard greens?
Avoid planting collard leaves with similar plants in the same family because they’ll compete for the same nutrients.
Don’t plant collards with kale, cauliflower, cabbage, or broccoli. If you have no space, consider using separate containers for each plant type.
With the right protection, you can grow collard leaves well into winter. Zones 8 and higher will net the juiciest crop possible by planting in the autumn for a winter harvest.
What month do you plant collards?
This depends on your hardiness zone.
Collards are a cold-loving plant and should be planted in spring, summer, or fall if you have a quick to harvest variety or live in a higher hardiness zone.
Transplants should be planted in spring or summer
Seeds should be sown based on their time to harvest and planted accordingly.
How late can you plant them?
The latest you can plant collards is about 60-80 days before the first frost date.
Avoid having the plant’s maturity date after the first frost.
If you can time it to mature right around the first frost date, that’s perfect. This is especially critical in zones 6-7 because this will kill the plant if it’s too cold.
For those in warmer regions, you have the freedom of planting almost anytime you want since it rarely gets cold enough to damage the leaves.
Growing collard greens in summer or fall
Collard greens can be sown and grown in the summer and fall for a winter harvest in southern states.
For northern areas, they need to be planted a bit earlier for a fall harvest, as the chill of winter will kill the plant.
The best piece of advice is to check the days to maturity on the package of seeds or transplants you bought and estimate the best time to plant by counting backward from the average first frost date.
Here are some additional references you may find useful:
Enjoy your collards during the winter!
You should now have some tidbits of knowledge to get the most out of your collard greens over the cold season!
Let them “chill out” and get some cold, but just watch out for any extreme temperature dips where you’ll need to get out there and protect them.
What do you think?
Are you going to give them a few touches of frost to get the most flavor? Post a comment and let us know!
Thanks for reading.
I took interest into microflora and microgreens before it became mainstream. The idea of growing an entire ecosystem on a tiny scale simply was astounding. That’s where I discovered that I actually like raising plants and wasn’t as much of a black thumb as I thought. Now, I’m relaying what I’ve learned to others who are getting into the hobby in a way that anyone can understand.