BLog

Some plants are simply not as tough as others—and in Minnesota, that reality can be hard to accept. We pour time, effort, and money into our gardens, only to watch certain plants struggle when winter arrives. Between fluctuating temperatures, drying winds, and inconsistent snow cover, even well-established plants can suffer. The good news? With the right winter protection, many tender plants can make it through and come back stronger in spring.

Winter mulching is one of the simplest and most effective ways to protect vulnerable plants in our Midwest climate.

Why Winter Mulch Matters

Winter mulch is not about keeping plants warm—it’s about keeping them stable. In our topsy-turvy winters, repeated freezing and thawing of the soil can be especially damaging. As soil expands and contracts, plant roots can be heaved out of the ground, exposed to cold air, and ultimately killed.

A proper layer of mulch:

• Insulates soil temperatures
• Prevents damaging freeze–thaw cycles
• Protects roots from drying winter winds
• Reduces moisture loss during cold, snowless periods

When to Apply Winter Mulch

Timing is critical. Mulching too early can encourage rodents or cause plants to retain too much moisture.

Best timing:

• Apply mulch after the ground has frozen and will stay frozen
• In the Twin Cities, this is typically mid to late November, depending on the year

Once the soil is frozen, plants are dormant and ready for protection.

What to Use for Winter Mulch

Not all mulch materials perform the same in winter. The goal is insulation—not compaction.

Straw

• Light, airy, and an excellent insulator
• Golden in color and does not pack down
• Ideal for perennials, roses, and tender plants

Leaves

• A readily available and eco-friendly option
• Shredded leaves work best to prevent matting
• Can be used alone or layered with straw

How Much Mulch to Apply

Depth matters:

• Apply 4–6 inches of mulch around the base of plants
• Cover the root zone thoroughly
• Avoid piling mulch directly against woody stems or crowns

The goal is even coverage that stays in place through winter storms and wind.

Which Plants Need Winter Mulch

Focus your efforts where they matter most:

• Newly planted perennials (first-year plants are especially vulnerable)
• Tender perennials, even some rated for Zone 4
• Plants known to suffer winter damage
• Marginally hardy plants grown near the edge of their zone

What About Zone 5 Plants?

The immediate Twin Cities area is classified as USDA Zone 4. If you are growing Zone 5 plants, they will need extra protection to survive.

For best results:

• Create a simple fence or enclosure around the plant
• Fill the enclosed area with mulch
• Make sure the mulch stays in place all winter

This added insulation can make the difference between winter loss and spring success.

Protecting Plants from Rabbits and Other Critters

Sometimes winter damage doesn’t come from cold—it comes from hungry wildlife. Rabbits, in particular, will feed on shrubs, perennials, and young trees throughout winter.

If rabbits are a concern:

• Surround plants with chicken wire or hardware cloth
• Combine physical barriers with repellents such as:
  • Liquid Fence
  • Shake Away
  • Pepper-based sprays

Using both barriers and repellents provides the most reliable protection.

A Little Effort Now, A Better Garden Later

Winter mulching may not be glamorous, but it’s one of the most impactful things you can do for your garden. A thoughtful layer of protection helps plants rest, recover, and return ready to grow when spring finally arrives.

If you’re unsure which plants need extra care or which mulch is best for your space, our team at Sunnyside Gardens is always happy to help you plan for winter success.