Garden beds covered in loose straw mulch beside a row of leeks

Hold the winter mulch until the cold sets in

Soil and compost
October 27, 2026

The first cold snap makes you want to tuck every bed in with straw. Wait. Mulch put down too early can delay dormancy and raise the risk of winter injury.

Mulch is for the freeze, not the cold

Winter mulch does not stop the ground freezing. Wisconsin Extension says it is to avoid freezing and thawing cycles. Iowa State says those cycles push shallow-rooted perennials up and expose crowns and roots to cold and drying wind. Wisconsin adds that snow cover does this job from December through March.

Strawberries are prone to heaving, along with coral bells, mums and shasta daisies, per Iowa State.

Wait until plants are dormant and the cold has set in, then mulch.

Timing by state:

A wooden raised bed covered in loose straw with a light frost, small green leaves poking through Straw laid over the plants helps avoid the freeze and thaw cycles that heave them.

What to use, and how deep

Straw and marsh hay lead the list, along with evergreen boughs. Leaves tend to mat down and may smother plants, says Wisconsin.

Depth varies, so check your own state's advice. Iowa State says 3 to 4 inches over the crown. Illinois Extension says 3 to 4 inches of clean, seed-free wheat straw on strawberries. Colorado says 1 to 2 inches.

Water first. Wisconsin says plants should not enter winter under drought stress, so water until the ground freezes.

Take it off in spring

Pull the mulch back gradually, not all at once. Iowa State says to start once the soil begins to thaw, around mid-March there. Illinois says wait until soil stays at 40 F for three or four days, and push the extra straw between the rows.

Colorado says to leave the mulch on as long as possible to hold back early growth, then remove it gradually, leaving as much as possible around the plants, and to rake it back over them if a late frost is coming.

Bottom line

  • Mulch strawberries and shallow-rooted perennials after the ground freezes, not before, per Iowa State.
  • Use straw, marsh hay or evergreen boughs, not matted leaves, per Wisconsin Extension.
  • Remove it gradually in spring, and keep it handy for a late frost, per Colorado State Extension.

Your zone

  • Zone 3-4: Wisconsin Extension says to mulch around Thanksgiving, once soil has just started to freeze.
  • Zone 5-6: Iowa State says late November and UNH Extension mid to late November, after the ground freezes.
  • Zone 7-8: In Oklahoma, OSU Extension says to mulch strawberries in early to mid-December, but if warm weather continues, wait for several hard frosts so plants become hardy.
  • Zone 9-10: LSU AgCenter in Louisiana says to mulch with loose, dry pine straw or leaves before a freeze and to remove a complete cover within three or four days.
  • Zone 11+: [VERIFY: zone 11+ guidance]

Sources

helpzone 3-4zone 5-6zone 7-8zone 9-10zone 11+
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Garden Hero

We have killed more plants than you have grown. Rooted is what we learned, sourced to the extension office and written by your zone.

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