Protection from frost is important to the health of your roses. If temperatures dip below 10℉ (-12℃), your roses will not survive unless you intervene to protect them. Once your roses freeze, the best course of action is to keep in freezing temperatures, because temperature fluctuations can eventually ruin rose bushes beyond repair. Through techniques such as mounding, bundling, and “hardening off,” you can protect your rose bushes from frost damage and keep them healthy throughout multiple seasons.
3 Ways to Protect Roses from Frost
If you have taken the time to plant and care for rose bushes, the last thing you want is a frost to come along and kill them. Fortunately, there are ways to prevent this from happening. Below are three innovative ways to protect roses from frost.
Protect Your Roses Through Mounding
Mounding is a great way to protect your roses from frost. This technique is implemented by using a shovel to pile soil around the base of your rose bushes. Use a rose collar to help keep the mound’s shape and insulate your roses.
- Trim your rose bushes in fall, so the canes are 10–15 inches tall (25–38 cm)
- Fit this rose collar around the canes at the base of each of your rose bushes.
- Mix together equal parts soil and wood mulch.
- Use a shovel to fill each rose collar with the soil-and-mulch mixture.
- Make sure the mound of soil is 8–12 inches (20–30 cm) high.
- When cold temperatures end, spread the soil out evenly around the base of your roses.
If you don’t want to use collars, you can make your own out of chicken wire or newspaper. No matter what you use, pile up the soil until you’ve covered the lower portion of your rose canes with 8–12 inches (20–30 cm) of soil. Once the danger of frost is past, spread the soil evenly around the base of your plants.
Bundle Your Roses Over Winter
Bundling is a great technique to protect roses during winter. This is accomplished by tying 2 to 3 canes together at a time in bundles with cotton string. Loosely pack the bundles with dry straw. Then, wrap the entire bundle with burlap or a similar fabric.
- Use this cotton string to tie 2–3 rose canes together into loose bundles.
- Wrap the string around the rose canes several times, to a height of at least 12 inches (30 cm).
- Stuff straw into the string bundle to form an insulating barrier around the canes.
- Wrap the bundle with this burlap gardening cloth to keep the canes dry and protected.
- If you wish, you can mound dirt around the canes after bundling to provide extra insulation.
Make sure you don’t tie the bundles together too tightly or abrade the canes with zip ties or rough-textured fasteners. Leave the bundles in place until temperatures begin to warm up. Make sure you do not untie them prematurely, since this will expose them to potential fluctuations in temperature, which could destroy your rose bushes.
Reduce Watering and Stop Providing Fertilizer
An easy-to-implement technique to protect roses from frost is to reduce both their fertilizer and their water approximately 6 weeks before the first average fall frost. This is sometimes referred to as “hardening off.”
- Stop providing fertilizer 6 weeks before the first fall frost.
- Cut watering by approximately 50 percent at the same time you stop fertilizing your roses in the fall.
- This technique thickens the cell walls of the plants, creating a protective barrier for the canes.
Hardening off your roses triggers the plant to thicken its cell walls. These thick cell walls give roses natural protection from frost. This sometimes gives the canes a purplish color, but rest assured this is normal and not a sign of disease.
Does Frost Hurt Roses?
Roses are fairly cold-tolerant, but frost can definitely hurt them, depending on the average temperature where you live during winter. Also, as the weather gets cold and temperatures begin to fluctuate, it can confuse your roses. Roses are more likely to be damaged by temperature fluctuations than by cold, which is why insulating your roses is essential. A layer of insulating dirt, mulch, or straw keeps roses from experiencing a deadly freeze-and-thaw cycle.
- Rose bushes are cold-tolerant overall, but frost can harm them.
- When temperatures fluctuate, roses get confused and can be harmed by cold.
- After a single frost, your roses may think it is spring again and try to bloom.
- When additional frosts occur, the shock can kill your roses.
- Protect roses against temperature fluctuations through mounding and insulating the canes.
When a single frost is over, your roses may think the weather is warming up and it’s time for them to bud. Then, the shock of the next frost comes and the roses may die. Roses have little chance of surviving temperatures below 10℉ (-12℃).
When Should You Protect Roses from Frost?
Be prepared to protect your roses from frost as soon as temperatures begin to drop. The key is to prevent your roses from being exposed to weather that shifts between frost and warmth. Steady cold or steady warmth are safe for roses, but repeated changes in temperature can destroy your plants.
- Offer your roses protection at the first sign of frost.
- Protect roses from temperature fluctuations to prevent serious damage.
- Climbing rose varieties are more adaptable to temperature fluctuations.
You can wait a little bit longer to protect climbing rose varieties than you will with rose bushes. Climbing roses are more adaptable to fluctuations in temperatures than other varieties. However, it is always best to err on the side of caution and give any type of rose protection at the first sign of frost.
How to Cover Roses from Frost
Roses survive winter best when they are insulated from frost. To keep your roses safe all winter, use these strategies:
- In temperatures lower than 10℉ (-12℃), roses may not survive on their own.
- Temperature fluctuations can eventually kill your rose bushes.
- Trim rose canes and mound soil around the canes to protect them from cold.
- Bundling rose canes with twine, straw, and burlap is another great way to keep them safe through winter.
- Reduce water and fertilizer for your roses 6 weeks before the first frost to “harden them off,” and help them survive winter.
Although cold weather can be tough for your roses, many rose varieties are hardy plants that can survive freezing temperatures for an extended period of time. If you are worried about the effects winter weather may have on your roses, consider planting a cold-hardy variety or naturally resilient climbing roses.