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Can Potato Plants Survive Frost? Only If You Protect Them

Learn the minimum temperature levels for potatoes and how to protect them from frost.

By
Sean Stratton | Updated January 4, 2023
Potato Plant

Think of a hearty cold-weather meal that doesn’t include potatoes. It’s hard, right? Winter is fast approaching, and potatoes are the perfect root vegetable to complement any meal, either as a side or as the main course!

But how does the freezing weather affect the potatoes in your garden? In this guide, we will give you lots of chilly information about potatoes in frosty weather. So, let’s dig in.

Can Potato Plants Survive Frost?

Potatoes will survive light frosts with temperatures between 29 and 32 degrees Fahrenheit. If temperatures drop below 28 degrees, tuber tissues near the surface can freeze, and the potato plants are more likely to experience damage.

How to Protect Potatoes from Frost

  1. Plant your potatoes 3 inches deep in mounded rows. This will help warm the soil faster.
  2. Place straw mulch or dry organic materials around your potato plants. This will work as insulation and keep the soil’s warmth locked inside.
  3. Use plastic, paper, or fabric row covers. Fabric row covers are the most effective.

Do Potatoes Recover from Frost Damage?

Temperatures below 28 degrees Fahrenheit can damage your potato plants. As a result of freezing cold, you may notice blackening around the leaf margins, the foliage can become limp, and in the worst case, your potato plant can fall to the ground.

Are you thinking this is the end? Surprisingly, ‘No’! According to Horticulture and Home Pest News, and Iowa State University Extension and Outreach, you should see new growth in 10 to 14 days. They said that this is true for severely damaged plants as well.

So, if you were thinking of replanting the potatoes after frost damage, you can take a step back now and wait for a few days to see new shoots come out.

Next Read: Need Fertilizers for Your Potato Plants?

Do Potatoes Need to Be Covered for Frost?

Yes, it’s better to cover your potatoes for frost. In some years, spring weather becomes quite aggressive to young potato plants. Your plants may face late frost or the “killing frost”. This late frost can really damage your plants.

If you fear killing frost this year, covering potatoes with organic materials can be a wise decision. Since frost damages the leaves and stems of the tinder plants, you can gently cover the entire plant with soil or organic materials, namely mulch, sphagnum moss, or straw. This will help keep the plants safe from late frost.

Not only for frost, ‘hilling up’ or covering potatoes with organic materials is beneficial for many reasons. Covering the potatoes with organic material can help tubers grow deep, allowing new tubers to grow.

This technique is also useful if you want to beat weeds around the potato roots. Plus, the depth of the soil and darkness impact the taste of the potatoes. Potatoes grown deep down in the soil will have a better flavor.

Also Read: Keeping Ants Out of Potato Garden

Saving Potato Plants after a Late Freeze

You can follow the steps below to save your potato plants after a late freeze.

1. Pruning Damaged Leaves:

First, cut off all the damaged leaves. Pruning them will make space for the new, healthy leaves.

2. Adding Mulch:

Add organic mulch around the plants. This will lock the ground warmth inside and reduce the chances of further damage. Plus, it will protect the young tubers from direct sunlight.

3. Tying with a Supporting Stick:

Your potato plants can become weak after frost damage. If the plant goes limp, you need to tie the plant with a supporting stick quickly. Hammer a strong stick into the soil near the plant and gently tie your plant to it.

4. Fertilizing:

Finally, you need to fertilize your late frost-affected plants. Do not apply the fertilizer immediately after the freeze. It can cause plant shock. Apply a good potato fertilizer two weeks after the frost.

The fertilizer should be rich in phosphorus but low in nitrogen. You can go for 8-24-24 or 6-24-24 or any other blend recommended by your local experts.

When to Cover Potato Plants

The process of ‘covering’ is a continuous process. You will need to cover your potato plants with loose organic materials multiple times, as described below.

When planting potato plant seeds, place them under 6 to 8 inches (15 to 20 cm) of soil. Then cover the seeds with rich soil or nutritious organic materials such as mulch, sphagnum moss, or straw.

When the potato plants reach a height of approximately 6 to 8 inches (15 to 20 cm), you need to hill up or cover the seedlings with organic materials. Remember, allowing only the top leaves to enjoy the sunlight is sufficient.

After the plants grow another 6 to 8 inches (15 to 20 cm), you need to gently cover the plants again. If you are growing potatoes in a small barrel or a bag, you must continue the process until you reach the top. You can also cover your tinder plants if you fear late frost.

Important Read: Why Do You Need 18-18-18 Fertilizer?

Frequently Asked Questions

How Long Can You Leave Potatoes in the Ground after Frost?

You can allow the potatoes to sit under the ground for only up to 2 weeks after the foliage starts to die.

Will Frost Kill Potatoes?

If the temperature drops to a level of 25 to 28 degrees Fahrenheit, your potatoes can be severely damaged. But when the temperature gets below 24 degrees Fahrenheit (-4.44 °C), your potato plants can no longer survive and will likely die.

What Does Frost Damage on Potatoes Look Like?

You can easily identify frost-damaged potatoes. The first thing you would notice with your bare eyes is that the skin is wrinkled and discolored. You may find some dark spots on the skin as well. If you split some damaged potatoes into halves, you may find the internal flesh has turned brownish and soft.

Written by Sean Stratton

Sean Stratton

Hi, I'm Sean, the senior editor here at Fertilizer Pick. I grew up on a farm in North Carolina and have grown fruits, vegetables, and trees since childhood. While I no longer live on a farm today, I still enjoy spending time on my garden and sharing my knowledge with friends and fellow garden enthusiasts.