How to Winterize Perennials in Oregon Successfully

As the weather turns cooler in Southern Oregon, now is the perfect time to help your perennial plants transition into dormancy and emerge next spring healthy and vigorous. At Hilton Landscape Supply, we’ve been serving the region’s gardeners and landscapers since 1956, and we understand the local climate, soils, and plant needs here in the Rogue Valley. In this essay, we’ll walk you through key steps to winterize perennials in Oregon, paying special attention to our local conditions and how you can use quality materials to protect your plants through the winter.

1. Understand Southern Oregon’s growing conditions

Southern Oregon presents a mix of climate features: relatively mild winters compared to colder inland valleys, but still with freeze-thaw cycles, variable rainfall, and sometimes dry soils under dormant plants. As temperatures begin to cool in the fall, it’s time to put your perennials to bed for the winter by watering and mulching them appropriately. Roots need to be supported, and crowns require protection from temperature fluctuations, soil drying, and frost heave cycles.

At Hilton Landscape Supply, we offer a wide range of mulch, soil conditioners, topsoil, and other materials designed to help perennials survive dormancy.

2. Clean up and prepare your perennial beds

The first step in how to winterize perennials in Oregon is to tidy up the garden: remove diseased or dead foliage, clear weeds, and trim spent stems. Cutting back perennials like Shasta daisies, mums, and rudbeckias after they finish blooming reduces disease carryover.

However, not all plants should be cut to the ground. Leaving seed heads and stems helps provide wildlife habitat and protects crowns. In Southern Oregon landscapes, leaving ornamentals like grasses or echinacea standing through winter adds texture, interest, and ecological benefit.

3. Water deeply before dormancy sets in

Even though the plants are going dormant, root zones still benefit from soil moisture. Dry soil can lead to root desiccation or reduce the resilience of plants when temperatures vary. A good deep watering in the fall ensures that perennials enter winter well-hydrated.

At Hilton Landscape Supply, we encourage the use of quality soils or amendments to help the root systems develop good structure and drainage. A well-amended bed retains moisture and supports healthy perennials through dormancy.

4. Mulch smart: Insulate but avoid pitfalls

One of the most reliable strategies to help you winterize perennials in Oregon is mulching. Mulch moderates soil temperature, reduces the risk of frost heave, prevents soil drying, and suppresses weeds.

Here are our recommendations:

Once the soil has cooled (after the first hard freeze or daily frost), apply a 2–4 inch layer of mulch, such as shredded bark, leaves, or wood chips.
Avoid placing mulch directly against the plant crown—leave a small gap to prevent rot or fungus.
Ensure good drainage: mulch helps insulation, but if water sits, perennials may suffer root rot or heaving due to freezing and thawing.
Hilton Landscape Supply offers bark mulch and decorative bark that serve both aesthetic and functional roles in winter protection.

5. Protect from freeze-thaw and frost heave risks

In Southern Oregon’s variable winters, one of the biggest enemies of perennials is not necessarily extreme cold, but the freeze-thaw cycle that causes the soil to heave, expose roots, or damage the crown.

To reduce these risks:

A consistent layer of mulch helps keep the soil temperature more stable and prevents repeated freezing and thawing near the root zone.
Avoid disturbing soil aggressively in late fall—work when the soil is still slightly warm and not saturated or frozen.
For perennials with shallow root systems or those in newer plantings, consider adding an extra layer of protection, such as burlap, a windscreen, or a temporary row cover, to block cold winds and ice crystals.

6. Use the right products and local expertise

Because every garden is unique, leveraging quality materials and local guidance can make the difference between success and struggle. Hilton Landscape Supply has been serving Southern Oregon homeowners and professionals for decades, and our inventory of soils, mulches, and amendments is tailored for the local climate.

Tips for choosing materials:

Select mulch or bark that is free of weed seeds, well-aged, and suitable for insulation tasks. Our decorative bark options are ideal for both function and form.
Consider using soil conditioners and compost blends to improve drainage and root health ahead of winter—our topsoil and soil amendment offerings can help.
If you’re unsure how much material you’ll need, our yardage calculator and staff expertise at our Central Point location can guide you.

7. Springtime reset and what to avoid now

While you’re working now to winterize perennials in Oregon, also keep in mind what not to do:

Avoid fertilizing late in the season, as encouraging new growth just before dormancy can expose plants to winter damage.
Don’t remove all foliage in every case—some plants benefit from a layer of dead stems and seed heads for insulation and wildlife habitat.
Wait until spring to remove mulch gradually so the crowns don’t suddenly face freezing conditions after insulation is pulled away.

Then, in early spring, once soil temperatures are stable and around the growing threshold, gently remove or relocate the mulch, clean up any remaining debris, and inspect for signs of crown heave or damage.

Commit now to a healthier garden next spring

Winterizing your perennials doesn’t have to be a burdensome task, but it does require a thoughtful approach aligned with Southern Oregon’s unique climate. By following these steps—cleaning up your beds, watering deeply, applying the right mulch, guarding against freeze-thaw cycles, and using quality products from Hilton Landscape Supply—you’ll give your perennial plants the best chance to bounce back strong and vibrant come spring.

If you’re looking for local resources or need help picking the right mulch, soil, or amendments, visit us at our Central Point yard or give us a call. We’re proud to support Southern Oregon gardeners with trusted products and expertise.

Now is the time to prepare—so you can look forward to a flourishing garden next season. Let’s winterize those perennials right.