To maintain a size of 3-4’ wide by 3-4’ high, Knock Out® Roses should be cut back once a year to 12” high. Check your rose bush from time to time in late winter/early spring, and when you start to see new shoots growing from the canes on your rose bush, that’s a good sign that it’s time to prune.
Gather your tools
You will need a few basic tools when the time comes to cut back your roses: gloves, hedge shears, and hand pruners.
Decide where to cut
Determining where to cut depends on what size you want your rose bush to finish. Your Knock Out® Rose will usually triple in size after cutting it back to about 12” tall, so you can expect it to grow to about 3’ by the end of the season.
Trim out smaller canes
After you cut back, check your rose bush for any smaller or damaged canes that may need to be removed to promote better growth and air flow in between branches. Remove these with your hand pruners.
Discard the debris
Once you have finished, be sure to gather and discard the debris.
Petite Knock Out® pruning steps
If you want your plant to maintain a size of less than 18” high, Petite Knock Out® should be cut back once a year to 4-6” high in late winter/early spring. Check your rose bush from time to time in late winter/early spring, and when you start to see new shoots growing from the canes on your rose bush, that’s a good sign that it’s time to prune.
If you want to cut back your plant less frequently, you can certainly do so, as Petite Knock Out® should maintain its height of about 18”. In this case, we recommend cutting back to 6” high once every two years. Check your rose bush from time to time in late winter/early spring, and when you start to see new shoots growing from the canes on your rose bush, that’s a good sign that it’s time to prune.
Gather your tools (Petite section)
You will need a few basic tools when the time comes to cut back your roses: gloves and hand pruners.
Decide where to Cut (Petite section)
Determining where to cut depends on what size you want your rose bush to finish. Your Petite Knock Out® will usually triple in size by the end of the season after cutting it back.
Trim your Rose (Petite section)
Using your hand pruners, trim each cane to the desired height.
The broader pruning context: general principles and timing
The pruning of rose bushes can be confusing, especially when you start talking about hybrid teas, old garden roses, shrub roses, once-blooming roses, and English roses. The class of rose and the time of year it blooms influence the type and amount of pruning. General pruning principles apply to all roses, but there are differences between classes. The closer one gets to species roses the less severe the pruning. Because of the variety of rose types available, one may need to have an understanding of how the rose flowers. Pruning should also be looked at as applying a few common sense principles to accomplish several tasks.
The majority of pruning is done in the spring. The goal of spring pruning is to produce an open centered plant. We cultivated our rose bushes in the spring with thorough cleanup, tidy pruning, and just the right start of fertilizer. We sat back all Summer enjoying our reward of blooms. Apply the last measure of fertilizer by mid-August. Use a general purpose fertilizer, low in Nitrogen, but higher in Potassium and Phosphorus. A good choice would be an 8-12-6 or a similar combination. You do not want high nitrogen to stimulate a lot of top growth. You can use a rose fertilizer, but most of those have a systemic insecticide added which you do not need. Also, they may be very slow release, still feeding the plants two months or more later, which the roses do not need.
Rate of Application: About 4 ounces per plant. This need not be measured out to each plant if you have groups of plants. By mid-Sept., in many areas plants tend to bloom into October and beyond if the weather holds. But you want them to stop. You can still cut a rose here and there for a bouquet. That is an ongoing basic question. In early November, prune the top third out of plants to reduce and eliminate snow damage if we receive an early, wet snow. Leave until spring.
Fall (the latter part of October), after the plants are dormant, is a good time to move roses. Make sure your roses (and all of your plants) go into winter with the soil moist. Fall rains may do this for you. Late Summer to early Fall and in the Spring are probably the only times during the year when you will go through your roses thoroughly. Most of the year you will visit them randomly, dead heading, cutting bouquets, etc. This makes fall an excellent time to make notes about the condition of plants, possible additions, removals, potential problems, possible companion plants to be added, etc.
Timing and regional considerations
Timing varies by region and rose type. Late winter (February or March) is often a good time for pruning roses, but see the individual rose profiles for more specific timing. For warm climates, pruning windows may shift, and Provence-style guidelines suggest pruning hybrids in early spring when buds swell. In colder climates, protect hybrid teas, grands, and floribundas by pruning the entire plant to a smaller size and shielding it for winter. For climbing roses, avoid heavy pruning in the first years; later, prune to two or three buds or about six inches for later bloom.
Pruning cuts: how to do them well
- Cuts should be no more than 5 mm (¼ in) above a bud and should slope downwards away from it to prevent water from collecting on the bud.
- Cut to an outward-facing bud to encourage an open-centered shape; for spreading habit, some stems can be shortened to inward-facing buds to promote upright growth.
- Cut to the appropriate height if a bud is not visible; cuts must be clean, so keep your secateurs sharp. For larger stems, use loppers or a pruning saw.
- Prune dieback to healthy white pith. Remove dead and diseased stems and spindly or crossing stems. Aim for well-spaced stems to allow free air flow.
- On established roses, remove poorly flowering old wood and saw away old stubs that have failed to produce new shoots. Except for climbing and shrub roses, prune newly planted roses hard to encourage vigorous shoots.
- Trace suckers back to their roots and pull them away.
Climbing and special-case pruning
Climbing or rambling roses: If your rose has long arching stems, is very tall, or needs support, it is likely a climber or rambler. Shorten by a third to a half on one thick old stem; for multi-stemmed roses, remove one or two of the oldest stems to near the base. If the response next season is a lot of strong but barren shoots, chances are a rambler; a less vigorous, flowering growth suggests a climber.
7 Rules for Pruning Roses
Feed all pruned roses with a general purpose or rose fertilizer in spring, and monitor soil moisture. After pruning, clean up leaves to reduce disease and pests for the next season.