When to Prune Knockout Rose Bushes

To have Knockout rose bushes in good condition, they should be pruned every year so that the Knockout rose bushes develop properly. In this article, we will explain when to prune Knockout rose bushes always to have the best Knockout roses.

Knockout rose bushes grow easily and very fast, a friend of mine has a 6 ft (1.8 m) Knockout rose bush in his garden!!!!! That is why Knockout rose bushes should be pruned every year for proper growth and to produce the best roses.

Knockout rose bushes are very cold hardy and can withstand temperatures as low as -25 °F (-32 °C). Caring for Knockout roses is not very difficult, and they adapt easily to any garden.

When to Prune Knockout Rose Bushes

It is recommended that your Knockout rose bushes maintain a size of 4 feet (1.2 m) tall and 4 feet (1.2 m) wide. That is why you should prune your Knockout rose bushes every year.

So, when to prune Knockout rose bushes? Late winter or early spring is the best time to prune Knockout rose bushes. When you begin to see new shoots on your Knockout rose bushes, it is a good time to start pruning.

As mentioned above, the best time to prune Knockout rose bushes is in the spring, from late February to mid-March (Northern Hemisphere). Be sure to prune your Knockout rose bushes after the frost is over.

Some gardeners prune their Knockout rose bushes in the fall but from my own experience I had better success pruning my Knockout rose bushes in the spring, I got better blooms.

If you live in USDA zone 5 we recommend our article about when to prune Knockout roses zone 5.

when to prune knockout rose bushes
Late winter or early spring is the best time to prune Knockout rose bushes.

When is the Best Time to Prune Knockout Rose Bushes

The best time to prune Knockout rose bushes is in spring. Once the frost is over is the right time to start pruning Knockout rose bushes. From the end of February to mid-March (Northern Hemisphere), you can prune your Knockout rose bushes without any problem, to get the best roses in your garden.

In previous years I pruned my Knockout rose bushes in the fall as I had been told, but one day another fellow gardener told me that he pruned his Knockout rose bushes in the spring and got better results. This article from the University of Illinois confirms that pruning roses in spring is the best time.

By pruning my Knockout rose bushes in spring I had better success with flowering and that is why I have only pruned my Knockout rose bushes in spring for several years now and recommend it to all my friends and readers.

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How to Prune Knockout Rose Bushes

To prune Knockout rose bushes, you will need hedge shears, hand pruners, and gardening gloves to protect yourself from rose thorns. Always disinfect the tools with which you prune Knockout rose bushes, you can disinfect the tools with alcohol.

Knockout rose bushes after pruning usually triple in size. That’s why if you prune your Knockout rose bushes to 12″ (30 cm) tall, then they will easily grow to 3 feet (90 cm) tall by the end of the season.

Begin by removing cross branches from your Knockout rose bushes. Prune branches that you notice are weak, diseased, very thin, or dead. You just want to have thick, strong stems on your Knockout rose bushes.

Always try to prune in such a way that the inside of the Knockout rose bush is aerated. When the bush is open and aerated, certain diseases are avoided in Knockout rose bushes.

Don’t be afraid to prune your Knockout rose bushes, they will grow fast and strong!!! Always remember to use sharp tools to make a perfect cut, this way the Knockout rose bush will heal faster.

Do not fertilize your Knockout rose bush after pruning, once new leaves begin to appear on your Knockout rose bush fertilize. Use 5-10-5 or 4-8-4 fertilizer for roses, the important thing to fertilize roses is that the fertilizer has a high potassium content. I recommend using gardening gloves and gardening sleeves when pruning Knockout roses.

how to prune knockout rose bushes
Always use sharp, disinfected tools when pruning Knockout rose bushes.

Rejuvenation Pruning of Knockout Rose Bushes

Rejuvenation pruning is when you prune your Knockout rose bush back to about 12″ (30 cm) tall, so the plant will grow very strongly from the large stems left on the Knockout rose bush.

If your Knockout rose bush did not grow properly last season or was attacked by disease or fungus, rejuvenation pruning is the best thing you can do for your Knockout rose bush.

This pruning will completely rejuvenate your Knockout rose bush and give it proper growth. It will probably take a little longer for the roses to bloom compared to regular pruning, but they will bloom.

rejuvenation pruning knockout roses
Rejuvenation pruning is ideal for roses that suffered from diseases or did not grow properly the previous season.
About Henry Morgan

We are the Morgan family, Henry, and Julia, both agronomists from the University of Michigan, where we met. We are experts in putting our hands in the soil and developing organic foods and improving production processes for decades. Likewise, we have worked for companies such as Mondelez International, BASF, Monsanto, etc. currently in our role as science writers for TheGardenStyle.com as well as advisors in promoting large scale food growing in urbanized areas. In this website, we share what we are most passionate about, gardening and farming. Enjoy and see real photos on our website.