Cabbage is a nutrient-rich, cheap, and versatile vegetable with a long shelf life. In addition, cabbage is a hardy plant and can tolerate frost; a light frost could even improve its flavor. However, a severe freeze can affect it and if you don’t save a freezing cabbage plant quickly, it can suffer irreversible damage.
You can save a freezing cabbage plant by watering the leaves and soil around it and pulling out any damaged parts later. You could also put a layer of mulch around it or cover it with a sheet to insulate it. After the cold period, you can feed the plant with fertilizer to boost its growth.
Frozen plants are a common problem for US gardeners in some states north of the frost line, such as Minnesota. However, while leaving the plant this way for too long will cause irreversible damage, there are ways to fix the problem before it’s too late.
Also Read: How To Get Seed From Cabbage Plant
A sudden and intense drop in temperature can affect your cabbage plants regardless of their growth stage.
A freeze occurs when the ground and air temperatures fall below the freezing point, and the air becomes dry. A particularly bad one like the February 2021 Texas winter storm could ultimately damage your cabbage plants.
Cabbage are hardy plants and generally, it’s OK to leave them in the ground over winter. However, they are only safe to temperatures as low as 21.2℉(-6℃). Sustained temperatures below that will eventually be a problem.
If you notice that your cabbage plants are freezing, it’s best to give them some water immediately.
When a cabbage plant freezes, ice forms between and within the cell walls of its tissue. As this happens, moisture is sucked from the leaf tissue, thus dehydrating the plant.
So, if you don’t do something immediately, the cabbage plant could die as it needs water to survive. Here’s how to water a frozen cabbage plant to save it:
- Water the soil around the plant: When there is a freeze, the cabbage plant and the ground around it freeze. The ice around the plant prevents water from penetrating its roots, which could cause dehydration and nutrient deficiencies. Therefore, it’s best to water the soil around the plant as the water will unfreeze the ground, and hydrate the roots.
- Pour lukewarm water on top of the plant: It could also be a good idea to pour water on top of the freezing cabbage plant to help melt the ice.
Cabbage is a hardy plant and can therefore withstand a bit of freezing. However, if a freeze continues for hours, it could damage your plants. After the freeze, the cabbage plants thaw, and you can then tell if there is any severe damage to the plants.
If the freeze seriously damages any cabbage plants, pulling them out is best as the damage is usually irreversible. Below is how to identify cabbage plants seriously injured by a freeze:
- After thawing, the leaves look limp and translucent (water-soaked).
- After thawing, the leaves may become brittle and curl up.
- The plant might have blackened foliage because a freeze also burns the plant’s tissue.
- If the plant has already formed a head, the head may split.
- If any of the plants have any of the above signs, it is most likely that the freeze severely damaged them. You should therefore pull out such plants and throw them away.
- However, if the cabbages have already formed heads, you can still use them even if the leaves look loosely wrapped around the head.
Here’s what to do with the freeze-damaged cabbage heads you pull out of your garden:
- Remove all the damaged leaves from the cabbage.
- Store the cabbages in a cold environment.
There might be some blackening on the outer layer of the cabbage heads. These cabbages are safe for eating as all you have to do peel off the damaged parts.
Check out: How Do I Know if My Cabbage Plant Is Dying?
Another way to save a freezing cabbage plant is by putting a heavy layer of mulch around it. Mulch is soil cover for plants and it could be in the form of seaweed, cardboard, wood chips, rotted manure, or compost. While it’s a temporary measure to reduce damage, it goes a long way during temperature drops.
After watering your freezing cabbage plants, the soil around the plants and the foliage of the plant thaws. After watering the plant, you can help it further by putting a heavy layer of mulch around it.
Here is how the mulch saves your freezing cabbage plant:
- It keeps the ground around the plants from freezing. The plant is, therefore, able to absorb moisture and survive.
- Mulch traps heat and increases the soil’s temperature. This prevents the cabbage plant from freezing.
After watering the freezing cabbage plants and pulling out the damaged ones, the plants will have a much better chance of surviving.
However, hard frost is unpredictable and can easily happen during the early morning hours when you are fast asleep. Therefore, it’s best to take preventive measures during cold months to protect the plant and enable it to grow to maturity.
Some of the ways you can protect the cabbage plant from further hard frost include:
A frost cover is a material that covers cabbages and other plants during cold seasons to prevent them from freezing. Frost covers can either be of lightweight or heavy-weight materials. Since cabbages are hardy crops, choosing a lightweight freeze cover like the WYRJXYB Plant Covers Freeze Protection kit (available at Amazon.com) is best.
This kind of frost cover is ideal for protecting your cabbage plants from further damage since it has quite a few benefits:
- It creates heat and retains warmth, thus preventing your cabbage plants from freezing again.
- It’s made of non-woven polypropylene fabric and is thus lightweight, allowing water and air to reach your plants.
- It’s a complete set. It comes with a frost cover, garden hoops, and garden clips, thus enabling you to create a simple, mini-greenhouse for your cabbage plants.
NOTE:Remember to remove the frost covers when temperatures rise so that they don’t overheat your cabbage plants. Overheating could do as much damage as the frost would.
Suppose you wake up and find that your cabbage plants are freezing and you don’t have commercial freeze covers. If this happens, you can cover the plants using old sheets from your home.
Although these may not work as efficiently as the commercial frost covers, they will provide some basic insulation and it’s better to have them than leave your crops completely exposed.
The bed sheets can help your freezing cabbage plants in the following ways:
- Trap in some heat to keep the plants warmer and protect them from freezing.
- Help the soil to maintain some moisture, preventing your plants from getting dehydrated.
- Allow some light and water to reach your plants for survival.
Since you might not have ready-made hoops and clips to put up the sheets, you can improvise with sticks. Here’s how to use the sheets to cover cabbage plants:
- Put stakes around the cabbage section of the garden.
- Put the sheets on top of the stakes and cover all the cabbage plants.
- Ensure the sheets extend to the ground to create a dome of insulation.
- Anchor the sheets to the ground using stones or bricks to prevent them from being blown off by the wind.
- Ensure that the sheets don’t touch any foliage of the plant so that there is proper air circulation
- Remove the sheets when the temperatures increase to prevent the plants from overheating.
Have a look: Homemade Bug Spray for Cabbage Plants
Once your cabbage plants have overcome the freeze, they can continue to grow to maturity. When the cold season is over, it’s good to boost the growth of the cabbage plants by feeding them with a liquid fertilizer. The fertilizer makes up for any nutritional deficiencies in your plants and increases their growth rate.
Below are some things to note about feeding the cabbage plants with fertilizer:
- Feed the plants when they present with two to four true leaves to prepare them for the next growth stage.
- Avoid feeding after the plants begin to form heads as this could lead to rapid growth that can cause cracked or split heads.
- When feeding the plant, always follow the manufacturer’s instructions.
Additionally, you may like some more gardening articles:
- Why Is My Cabbage Plant Giving Tall Sprouts?
- Why Are My Cabbage Leaves Turning Purple?
- Why Are My Cabbage Leaves Turning Yellow?
- Holes in Cabbage Plant Leaves? [What needs to do]
- Cabbage Leaves Turning Brown? [Causes & Cares]
Cabbage is a hardy plant and can withstand most climates. However, winter can be unpredictable; the temperatures can shift to extremes within a few hours. Such temperature shifts can freeze a cabbage plant, and if you are not careful, it could damage the plant.
A little watering can go a long way for a quick solution. If the freeze comes suddenly or lasts longer than safe, a plant cover could save your plants.
I’m Elsa, and I love gardening. I started GardeningElsa.com as a resource for other gardeners, and I offer expert advice on gardening topics such as plants, flowers, herbs, and vegetable gardening. On my website, I share my latest tips and tricks for creating beautiful gardens. When I’m not working on my website, you can find me in my own garden, tending to my plants and flowers. Read more about me.