Like every other aspect of Knockout Rose care, preparing Knockout roses for winter is simple and straightforward.
The Knock Out rose, introduced by Will Radler in 1989, is very hardy in mild climates. However, the drought, black spot disease resistant Knock out roses do require some special care in areas that experience very cold temperatures and/or high winds in the winter.
In USDA zones 5b-11, winter protection of Knock Out roses is very simple, indeed. A bit more caution and preparation are needed in zone 5a.
- How To Prepare Knockout Roses For Winter in Zones 5b-11
- how to winterize knockout rose bushes: Special Winter Protection Instructions For Zone 5a
- Winterizing Knockout Roses Optional Steps
- How many varieties of Knockout Roses are there?
- Do Knockouts Need Deadheading?
- How Much Sun Do Knockout Roses Need?
- What Pests and Diseases Do Knockout Roses Plants Have?
Here’s what you need to know about knockout rose bush winter care.
How To Prepare Knockout Roses For Winter in Zones 5b-11
- Prepare your Knock Out rose bush in advance of the first frost by raking the ground clear around each of the roses in your garden. Pull out your pruners and do a light pruning to tidy up unruly canes or branches.
- Provide your knockout roses in winter with a fungicide treatment. In cooler climates (e.g., 5a), use a powdered product. In warmer, drier areas, you can use a light treatment of liquid fungicide.
- Mulch around each of the Knock Out rose plants in your garden to help keep the soil temperature consistent. Two or three inches of good-quality mulch is advised. Be careful not to let the mulch touch the plant as this will encourage rotting.
- As spring approaches, begin to prune. You want to perform your spring pruning while your roses are still dormant.
Pruning knockout roses for winter is essential for lots of spring blooms.
Your late winter/early spring pruning should be fairly aggressive.
Here’s how to prune roses for winter:
- Remove damaged limbs
- Cut out dead wood
- Remove interior stems for better air circulation
This is also an excellent time to shape your rose bushes, as you will have a clear view of the “skeleton” of each plant.
Related: Learn more about Pruning Knock Out Roses
how to winterize knockout rose bushes: Special Winter Protection Instructions For Zone 5a
Rake and prune your bushes as in steps 1 and 2 above. Watch out for the thorns! Have some plastic foam rose cones on hand to protect your roses against both cold and high winds.
After you have done your initial trimming, try fitting the cones over your bushes. If they don’t fit, more pruning is necessary.
Once you have your bushes properly trimmed to be fitted with rose cones, you can apply a fungicide. In zone 5a, you must use a powdered product because liquid products tend to freeze.
After applying fungicide powder to all of your plants, shape the soil at the base of each plant into a sloping mound. It should be eight or ten inches high and should make contact with the lower stems of the bushes.
With trimming done, fungicide treatment complete, and soil in place, you can fit your cones to each bush.
Next, mulch around the bushes with leaves or straw. You should add several inches of mulch to each of your soil mounds. This will provide extra insulation and protection against cold.
Don’t forget to consider the knockout roses temperature tolerance. Knockout roses have a relatively high cold tolerance and can withstand a wide range of temperatures.
While they are more resilient than other types of roses, they may still require some winter protection to stay in top condition.
Winterizing Knockout Roses Optional Steps
Remember that wildlife gets hungry in the wintertime. If there are deer in your neighborhood, you may want to take the added step of covering the tops of your shrubs with burlap sacks. This will prevent deer from nibbling during lean and hungry times.
There is an alternative if you don’t have plastic foam rose cones. Wrap a length of rope around each shrub very lightly. You’ll want to work your way from the bottom of the bush to the top. The aim is to prevent individual limbs from being broken by high winds.
This method doesn’t protect rose shrubs against cold.
If you are using the rope method to defend against the wind, you will definitely want to add some other sort of protection against cold (e.g., pine needles, extra straw or foliage, and a burlap bag).
Once your roses are covered for the winter, you shouldn’t need to do much to them. Make sure they are well watered in advance of the first freeze.
After the first freeze, they will go dormant for the winter and will not need much care until spring.
Taking these steps, you can look forward to preparing your hardy Knock Out rose for the upcoming blooming season of flowers.
Related: More on flowering with When do Knock Out Roses bloom?
Knockout Rose FAQs
How many varieties of Knockout Roses are there?
There are single and double Knock Out Rose varieties. Both single and double Knockout varieties come in an array of colors. Knockouts also come in both shrub and tree varieties.
Below is a list of Knockouts that make it easy to plant them in your landscape no matter how much space you have to work with.
- Original Knock Out (Rosa Radrazz) – Bright red blooms turn deeper red in the hot summer months
- Pink Knock Out (Rosa Radcon) – Deep, unscented light pink blooms that deepen in color as the growing season progresses.
- Peachy Knock Out (Rosa Radgor) – They look peachy due to their pink petals and yellow centers.
- White Knock Out (Rosa Radwhite) – These are white with a light floral scent and dark green leaves.
- Petite Knock Out (Rosa meibendino) – In a bright red color, these miniature roses are easy to care for and are great for pots.
- Pink Double Knock Out (Rosa Radtkopink) – Bright pink double flowers that are drought tolerant.
- Blushing Knock Out (Rosa Radyod) – Mossy green foliage, single, light pink flowers fading over time to a very soft pink.
- Rainbow Knock Out (Rosa Radcor)– is more compact and has a mix of coral/pink flowers with yellow centers.
- Sunny Knock Out (Rosa Radsunny)– is one of the most popular due to its citrus fragrance.
- Coral Knock Out (Rosa Radal) – These roses start out red and fade to coral, and they have a slightly clean aroma.
Do Knockouts Need Deadheading?
Knockout rose bushes are self-cleaning. They do not need deadheading. However, removing fading flowers helps the plant put more energy into producing new growth and new blooms.
How Much Sun Do Knockout Roses Need?
Most knockout roses like full sun and do best with 6-8 hours of sunlight. How much light you give your roses will affect how quickly they grow and their overall health. The more sun, the better!
Knockouts can tolerate different conditions but prefer full sun to partial shade. In addition, these hearty roses are drought-tolerant but are very sensitive to extreme heat.
What Pests and Diseases Do Knockout Roses Plants Have?
Besides black spots, here are a few others:
- Rose slugs can cause significant damage to Knockout roses. The “slugs” eat the leaves, resulting in a skeletonized appearance.
- Fungal Diseases – Knock Out roses are typically resistant to most diseases. But they can still be susceptible to some leaf spot infections, rust, and more.
- Japanese Beetles are common pests that feed on the leaves and flowers, creating a threat to the roses’ health.
- Powdery Mildew, a common fungal disease, appears as a white or gray powder on leaves and stems and can stunt growth.
- Sawflies, of which rose slugs are a type. Their larvae consume rose leaves, causing significant damage.
- Neem Oil is a natural pesticide and fungicide used to treat various pests and diseases. From fungal disease issues to the insects that plague these roses.
- Horticultural Oil is often used to control a variety of pests, including Japanese beetles and sawflies.