What Temperature Can Strawberry Plants Tolerate

If you grow strawberries, you know protecting them from temperature swings is key. One of the most common questions gardeners ask is what temperature can strawberry plants tolerate. The answer isn’t simple, as it depends on the type of plant, its stage of growth, and how well you prepare it. This guide will give you the clear, practical information you need to keep your plants safe through the cold months and ensure a strong harvest.

Strawberries are surprisingly tough, but their cold tolerance has clear limits. In general, dormant, well-established strawberry plants in the winter can survive temperatures down to about 20°F (-6°C) without protection. However, the real danger often comes from spring frosts that damage new flowers and fruit.

Here’s a quick breakdown of critical temperature thresholds:

Dormant Crowns & Leaves: Can tolerate brief periods as low as 10-15°F (-9 to -12°C) when properly hardened off.
New Spring Growth (Leaves): Damage can occur at 28-30°F (-2 to -1°C).
Open Flowers: Are killed at 30°F (-1°C).
Tiny Developing Fruit: Can be damaged at 28°F (-2°C).

Understanding the Different Types of Strawberries

Not all strawberry varieties handle cold the same way. Knowing which type you have is the first step to proper protection.

June-Bearing Strawberries: These are typically the most cold-hardy. They establish strong roots and go fully dormant, making them best for regions with severe winters. Popular hardy varieties include ‘Jewel,’ ‘Allstar,’ and ‘Sparkle.’
Everbearing & Day-Neutral Strawberries: These are less cold-tolerant. They produce fruit throughout the season and don’t go into as deep a dormancy. They often need more careful winter protection and are sometimes grown as annuals in very cold climates. Examples are ‘Albion’ and ‘Seascape.’

The Role of Plant Dormancy in Cold Survival

Dormancy is a strawberry plant’s winter survival strategy. As daylight shortens and temperatures drop in fall, the plant slows its growth and focuses energy into its crown and roots. This process, called hardening off, is crucial. A sudden, early freeze before dormancy can be devastating.

You can encourage dormancy by:

Stopping fertilizer applications in late summer.
Reducing water slightly in early fall (but don’t let them dry out completely).
Allowing the plants to experience those first light frosts without covering them immediately.

Why Spring Frost is Often More Damaging Than Winter Cold

It seems counterintuitive, but a late spring frost can do more harm to your harvest than deep winter cold. In winter, the plant is safely dormant. In spring, it’s actively producing vulnerable flowers. A single night at 30°F when plants are in full bloom can wipe out your entire berry crop for that cycle, even though the plant itself will survive.

Step-by-Step Winter Protection for Strawberry Beds

Proper winter care ensures your plants survive and thrive. Here’s what to do, step by step.

Choose the Right Time: Apply winter protection after the first few hard frosts (when temps are consistently around 20°F at night). This allows the plants to fully harden off. Applying mulch to early can smother them.
Clean the Bed: Remove any dead leaves, weeds, and old straw to reduce disease and pest hiding spots. You can mow or shear back the foliage to about 1 inch above the crowns, but be careful not to damage the crowns themselves.
Water Deeply: Give the bed a thorough watering before the ground freezes. Hydrated plants are more resilient against winter desiccation.
Apply Insulating Mulch: This is the most critical step. Use 3-4 inches of loose, weed-free straw, pine needles, or shredded leaves. The goal is not to smother, but to trap insulating air pockets. Avoid using whole leaves, as they mat down and can rot the plants.
Monitor in Spring: As temperatures consistently warm above freezing in early spring, begin gradually removing the mulch. Spread it between the rows to keep weeds down and protect against late frosts. Keep some handy to re-cover if a late frost is forcasted.

Emergency Frost Protection in Spring

When a late frost threatens your blooming plants, you need to act fast. Here are your best options:

Floating Row Covers (Frost Blankets): This is the most effective method. Drape a lightweight (0.5 oz) row cover over the plants before sunset to trap ground heat. It can provide 2-8°F of protection. Remember to remove it during the day.
Straw Mulch: If you still have straw from winter, you can gently pile a little around the base of flowering plants overnight. It’s less effective for flowers but can protect the crown.
Watering: Irrigating the soil before a frost can help, as wet soil holds heat better than dry soil. However, avoid getting the blossoms wet if possible.

Never use plastic sheeting directly on plants without support, as it can transfer cold and damage leaves where it touches.

Signs of Cold Damage and How to Respond

Even with protection, damage can occur. Here’s how to identify it and what to do.

Blackened or Mushy Crown: This is severe winter kill, often from extreme cold or wet, soggy mulch. The plant likely will not recover and should be removed.
Dark, Water-Soaked Leaves or Flowers: Classic frost damage. The damaged tissue will turn brown and crisp. Gently prune away the damaged leaves and blossoms. The plant will usually send out new growth if the crown is okay.
Stunted or Misshapen Young Fruit: This is from frost damage to the flower’s pistil. The fruit that does develop may be small or odd-shaped. There’s no fix, but the plant will produce more flowers later.

Selecting the Most Cold-Hardy Varieties

If you live in a cold zone (USDA zones 3-5), starting with tough varieties is your best bet. Look for these proven performers:

‘Winona’: Extremely hardy for northern gardens with good disease resistance.
‘Mesabi’: Developed in Minnesota, known for exceptional cold tolerance and great flavor.
‘Fort Laramie’: A very hardy everbearing type that’s a good choice for those wanting a longer harvest season in cooler areas.
‘Cavendish’: A June-bearer from Canada, excellent for hardiness and productivity.

Always check with your local extension service for varieties that perform best in your specific microclimate.

Growing Strawberries in Containers in Cold Climates

Potted strawberries are far more vulnerable because their roots are exposed to the cold air on all sides. They cannot survive freezing temperatures in containers without major intervention.

Your options are:

Move Containers to an Unheated Garage or Shed: After the plants go dormant, water them well and move the pots to a sheltered, unheated space. Check soil moisture monthly; it should be barely damp.
Bury the Pots: Dig a hole in a garden bed and sink the entire container into the ground. Cover with mulch just like an in-ground bed.
Insulate Heavily: If moving isn’t possible, group pots together against a sheltered wall, wrap the pots in bubble wrap or burlap, and pile mulch over the top of the soil.

FAQ: Strawberry Cold Tolerance

Q: At what temperature do strawberry plants freeze?
A: The plant tissue itself freezes around 28-30°F, but dormant plants can survive much colder air temperatures (down to 10-15°F) because of the insulating effect of snow and mulch protecting the crown.

Q: Can strawberry plants survive a frost?
A: Yes, dormant plants survive frost easily. The big risk is a frost after spring growth and blooming has begun, which can damage flowers and young fruit.

Q: Should I cover my strawberry plants at 32 degrees?
A> If your plants have open flowers or small fruit, yes, you should cover them. At 32°F, frost can form and damage these sensitive parts. If the plants are dormant or only have leaves, covering is usually not necessary at that temperature.

Q: How cold is too cold for strawberry plants?
A> For unprotected, dormant plants in the ground, sustained temperatures below 15°F can be risky. For plants in active growth, anything below 32°F is a threat. With proper mulch, strawberry crowns can survive winter temperatures well below zero.

Q: Do strawberries come back after a freeze?
A> The plant itself often will if the crown survived. However, the flowers and fruit killed by a freeze will not recover for that season. The plant may produce new blossoms later, depending on the variety and the timing of the freeze.

By understanding what temperature can strawberry plants tolerate and taking the right steps at the right time, you can enjoy healthy plants and a succesful harvest year after year, no matter where you garden. Paying attention to the weather and your plants’ specific needs is the ultimate key to success.