Last Updated on October 9, 2026
How to Overwinter Strawberries: Mulch, Pots and Raised Beds
To overwinter strawberries, cover the plants with 4 to 6 inches of clean straw after two or three frosts have hardened them off, and get it on before temperatures drop below 20°F. In spring, rake the straw off when new growth starts and keep it close by in case frost comes back. Plants in pots need more than mulch: move them into an unheated garage or replant in spring.
The trigger is temperature, not a date. A strawberry crown can be killed at 15°F, which is why winter protection matters even though strawberries are perennials (University of Minnesota Extension). Below 20°F, unmulched plants can lose flower buds, roots and crowns, and repeated freezing and thawing can heave them out of the ground (Iowa State University Extension).
How to overwinter strawberries by setup
| Setup | Winter protection | Straw depth | Source |
|---|---|---|---|
| In the ground | Leave plants in place and cover them with straw once they have hardened off | 4 to 6 inches over the top of the plants | University of Minnesota Extension |
| Raised bed or strawberry pyramid | Needs more protection than ground level: temperatures in raised beds can be several degrees colder in winter | 6 to 8 inches of straw | Iowa State University Extension |
| Pot or strawberry jar | Likely to be seriously damaged or killed if left outdoors. Move it into an attached, unheated garage, or discard the plants, store the pot indoors and replant in spring | Not a mulch job; move the pot | Iowa State University Extension |
| Vertical tower or hanging planter | A container with roots above the ground, so treat it like a pot: into an unheated garage, or replant in spring | Not a mulch job; move it | Inferred from Iowa State’s “strawberry jar or other container” wording (towers aren’t named by any source) |
In a raised bed, my strawberry spacing page plants 1 per square foot, so a 4 x 4 bed of 16 plants takes one even blanket of straw across the whole bed.
When to mulch strawberries for winter
Wait for the plants to harden off first. Plants mulched too early are more likely to suffer winter injury than plants mulched after they have hardened (Iowa State Extension). Next season’s fruit buds develop during fall cold acclimation, acclimation needs photosynthesis, and plants mulched before it is complete will not be fully winter-hardy (Cornell’s berry blog, written for commercial growers).
These signs mean the plants are ready for mulch (Iowa State Extension):
- Leaf color. Dormant leaves lose their bright green and take on a grayish or sometimes reddish cast.
- Cold nights. Several nights in a row of around 20°F.
- Cold soil. Soil temperatures consistently below 40°F for several days in a row.
Put simply: cover the plants after 2 or 3 frosts have hardened them off (University of Minnesota Extension). To see when your first fall frost usually arrives, look up your frost dates on Plan My Garden by zip code. That date tells you when to start watching the plants, not when to mulch.
How to mulch strawberries for winter, step by step
- Clean up the bed. At the end of the season, remove all the runners, as my strawberry growing guide describes, and clear out dead leaves and plants.
- Get clean, weed-free straw. Oat, wheat or soybean straw all work (Iowa State Extension).
- Cover the whole plant. Spread the straw over the tops of the plants, not just around them: 4 to 6 inches in the ground (University of Minnesota), 6 to 8 inches in a raised bed (Iowa State).
- Hold it down in windy spots. Lay wire or plastic fencing over the straw and weight it with bricks (Iowa State Extension). In my winter garden prep, I find straw blows around less than leaves do.
- Let snow do the rest. Snow is an excellent insulator, and a good snow cover on top of the straw helps (University of Minnesota Extension). Straw matters most in late fall and early spring, when bitter cold can come with no snow on the ground.
Straw beats leaves here. Leaves are not a good winter mulch for strawberries: they mat together in layers, trap ice and hold excess moisture against the plants (Iowa State Extension). Over the crowns, use straw.
Overwintering strawberries in pots
Strawberries in a strawberry jar or other container will likely be seriously damaged or destroyed if left outdoors in winter (Iowa State Extension). You have two options: move the container into an attached, unheated garage, or discard the plants in fall, dump the potting soil, store the pot indoors and replant in spring. No garage? Colorado State Extension‘s advice for container perennials in general: sink the pot into garden soil and mulch heavily over it, or tuck pots against the house’s north or east side.
If you replant each spring, day-neutral and everbearing varieties do better in containers than June-bearing ones (Iowa State Extension). Wood Prairie sells organic potted strawberry plants, including Albion, Cabrillo and Seascape; code PMG5 takes 5 percent off.
When to remove straw from strawberries in spring
Pull it off when the plants start growing. Check the plants through spring and remove the mulch when about 25% of them show new growth, which is white or yellow (Iowa State Extension). Removing it too early can push the plants to bloom before the danger of frost is past.
Leaving it on too long hurts too. Mulch left on well into spring can lead to crown rot and starved plants that do not recover in time for harvest (Cornell’s berry blog, written for commercial growers).
When you take it off, rake the straw into the aisles or alongside the bed, and leave some at the base of the plants as summer mulch (University of Minnesota Extension). My growing guide gives the same spring routine: pull the straw back so the plants are exposed and leave the mulch between them to hold down weeds.
Frost risk after the straw comes off
A temperature of 32°F or lower may severely damage or destroy open flowers, and the first flowers make the largest berries (Iowa State Extension). So keep the straw handy.
- Rake it back over. If frost threatens during bloom, lightly rake the mulch back over the plants (Iowa State Extension).
- Or use row cover. If frost is predicted after flowering begins, re-cover the plants with straw or spun-bonded polyester row covers (University of Minnesota Extension). My guide on how to protect plants from frost covers row cover weights and how to anchor them for the night.
Strawberries are rated a hardy perennial on my vegetable frost tolerance chart, the planner’s hardy class applied to a perennial crop: they stay in the ground over winter and get mulched in fall. The rest of the bed is in my steps to prepare your garden for winter. Healthy plants kept tidy can produce for three to five years, so the bed is worth protecting every winter.
Quick questions
When should you mulch strawberries for winter?
After the plants harden off. University of Minnesota Extension covers them after 2 or 3 frosts. Iowa State University Extension looks for grayish or reddish leaves, several nights around 20°F and soil below 40°F for several days, and says to mulch before temperatures drop below 20°F.
How deep should straw mulch be on strawberries?
4 to 6 inches over the top of in-ground plants, as University of Minnesota Extension recommends. Iowa State University Extension says raised beds and strawberry pyramids run colder and need 6 to 8 inches.
When do I take the straw off strawberries in spring?
When about 25% of the plants show new growth, which Iowa State University Extension says is white or yellow. Rake the straw into the aisles and leave some at the base of the plants. If frost threatens during bloom, rake it back over them.
Can strawberries in pots stay outside over winter?
Usually not. Iowa State University Extension says strawberries in a strawberry jar or other container will likely be seriously damaged or destroyed if left outdoors. Move the pot into an attached, unheated garage, or replant in spring.
Can I use leaves instead of straw to mulch strawberries?
Straw is better. Iowa State University Extension says leaves are not a good winter mulch for strawberries because they mat together, trap ice and hold excess moisture against the plants.
Plan the strawberry bed
A strawberry bed stays put for years, so it is worth planning once. Plan My Garden is free to start: enter your zip code and it finds your frost dates, draw your beds, pick strawberries and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates.
Related: How to Grow Strawberries in Pots or a Raised Bed · How Many Strawberry Plants per Square Foot? · How to Protect Plants from Frost · Vegetable Frost Tolerance Chart
