How to Plant and Design a Knockout Rose Garden

Preparing for your rose gardening can help you handle the chore better. The first step in preparation is arming yourself with basic knowledge about the plant itself, the knockout roses. This include a little bit about its history, characteristics, advantages, availability, and the tools you needed to start your knockout rose garden.

Knockout Rose Gardening Basics


In the same year it was introduced, knockout roses received positive reviews from several homeowners and nursery owners alike. It also bagged the prestigious All-American Rose Selection award in that year. Nurseries and growers consider these roses as one of the most in-demand breeds in the country. The man behind this best-seller is no other than Wisconsin’s William Radler.


The flowers vary from red to pink with different darkness or lightness. As mentioned previously, they produce clusters of flowers. The average height and width of a typical knockout rose is 3 feet.


Radler’s main objective in creating the knockout rose is to create a rose that has high resistance to diseases that have infested and killed numerous rose breeds before. He succeeded in providing highly resistant rose breed though there are still plant problems such as pests and graver plant illnesses that can defeat the knockout rose. Because of its resistance, growing and maintaining it is more manageable. You don’t have to do much spraying to cure or prevent diseases.

Knockout roses are one of the few plants that can survive zones ranging from 4 to 9. Given the proper care, they can survive winter and get ready to bloom in the next seasons. Their sturdy stems make this possible.

When it comes to beauty, knockout roses make it to the top list. They can be grown under evergreens or on slopes matched with other bushes and other landscaping elements. Their flowers can be cut for display or the plant itself may be potted or hanged. Most of all, they bloom abundantly and continuously except in their dormancy period.


Sunny knockout roses (Rosa Radsunny), blushing knockout roses (Rosa Radyod), double knockout roses (Rosa Hybrida Radtko), rainbow knockout roses (Rosa Radcor), and pink knockout roses (Rosa Radcon) are the most in-demand types of knockout roses.

The sunny knockout roses are known for their golden-yellow petals that will become soft yellow eventually. Blue-green leaves and shell-pink colored petals best describe the blushing knockout roses. Even if their flowers receive only three hours of sunlight, blushing knockout roses can still bloom. Double knockout roses, on the other hand, have 18 to 24 petals that are deep cherry red in color.

They are also considered as self-cleaning roses. Though lacking in fragrance, rainbow knockout roses don’t fail in charming its witnesses. At the top of its densely bush that has round dark green foliage are coral pink colored roses and yellow in it the flower’s center. As the name suggests, pink knockout roses are pink in color though they may vary in the darkness or lightness of the color. The leaves of these knockout roses are dark green-colored highlighted by blue shades.

You can purchase knockout roses from nurseries and growers. They are also available at some supermarkets. You also have the option to shop online for these plants. Shopping online can even save you from travelling costs. However, some online sellers of knockout roses don’t ship plants to Alaska and Hawaii.


Even before you get hold of your knockout rose, make sure you have the necessary tools right away. While you are shopping, you can shop for these tools as well. These tools are bypass pruners, hand loppers, saw, shovel, rake, a soaking hose or watering wand, gloves, kneeling pads, and sharpener.

Having the right tools helps you give your roses the best care


There are several types of pruners for sale but bypass pruners are recommended for rose gardening. Bypass pruners facilitates even cutting of your roses unlike other pruners that cut unevenly. This feature is important because uneven cuts can attract plant diseases. This tool will be used in deadheading and pruning. After you purchase your pruned rose, you will prune again before you plant them.

Hand Loppers

Hand loppers simply have longer handles than the typical pruners. It has the same task as the pruners but hand loppers are intended for thicker and stronger plants. They are also used for pruning plants that are difficult to reach. While both of these tools can be used for pruning, it is still recommended to have both. It’s because the long handles of hand loppers can make it difficult to accurately cut the stem of short and thin plants. On the other hand, pruners are too short and too weak to cut thicker stems.


Unlike pruners and hand loppers, acquiring a saw can be optional. If you have sturdy plants and trees in your garden that you want to get rid of, then you will need a saw.  Otherwise, you can save the money for purchasing other tools.


Before and after you plant a knockout rose, you will remove and move soil. While you may do this task using your bare or gloved hands, having a shovel will make it easier and faster. They can also be used to mix rose food, fertilizer, and mulch afterwards. Aside from that, you can use this in case you want to move or remove your knockout roses. A pointed shovel is the best for rose gardening.


Rose gardening requires cleaning. A rake comes in handy in this task. This tool will help you remove leaves from other plants and debris in the ground. As a result, you are minimizing probable sources of plant illnesses.

Soaking Hose or Watering Wand

When it comes to watering demands, you should choose a hose or watering wand over a watering can. A hose and watering wand are used to direct water to the roots. On the other hand, using a watering can entails wetting the leaves. Wet leaves can lead to acquiring of diseases.


While roses are pleasant to the eyes, they can be hurtful to the hands because of their prickles. That is why you will need gloves in both planting and maintenance chores. When you shop for a pair of gloves, make sure its thick enough to protect you from thorns but flexible enough to allow you to use your hands. They should be long as well.

Kneeling Pads

Kneeling pads are just like gloves; they both provide comfort and protection to a gardener. As the name suggests, kneelers protect your knees in case a thorny stem is scattered while you are gardening. Unlike other tools, you don’t have to spend much for this one. You can use old pillows and boards to protect and to have a comfortable rest for your knees.


If there are tools for you and for the roses, there is a tool for the tools as well. This comes in the form of sharpener. When you use your pruners, hand loppers, or saw, they must be sharp. Due to extensive use, they may become dull. A sharpener can help you extend the life of these tools.

Setting Up a Rose Garden

Rose gardening is easier said than done. After acquiring the tools, you will need to start setting up your garden. This is best done before you actually purchase your rose. In this stage, there are five basic considerations namely the area, soil, irrigation, spacing, and companion plants.


Make sure your zone matches the requirements of the knockout rose you want to purchase. You can check the USDA Plant Hardiness Zone for this. You may be able to cultivate a rose that is not well-suited in your area but don’t expect that it will grow or bloom richly.

When it comes to its sunlight needs, 5 to 6 hours of direct morning sunlight is recommended by most rose growers. Choose an area in your garden that receives such in the morning but is shady during afternoons. Afternoon sunlight is usually warmer; thus, more damaging than helpful to knockout roses. However, if you don’t have the recommended area, you still have a few options of knockout roses. Other types can survive without receiving direct or continuous morning sunlight after all.

Once you decided where you will be setting up your rose garden, do some cleaning. Get rid of the pests and infected plants. Remove the weeds and grasses as well. If you are using pesticides, don’t overdo it. It may leave chemicals in the soil that may harm your plants and kill even the beneficial insects.


The appropriate pH level for the rose’s soil is usually within the range of 6.0 to 6.8. Roses, in general, prefer slightly acidic soil. But for knockout roses, make sure the ph of your soil falls into the range of 6.3 to 6.8 rather than 6.0 to 6.2. To know the soil pH, conduct a test.

Aside from soil pH, get to know the right soil amendments that will help your knockout roses grow and bloom better. Soil amendments are added to the soil to make it rich in nutrients; thus, benefiting the plants. Other soil amendments are also used to alter the pH of the soil.

Manure and compost form part of soil amendments. These elements add acidity to the soil. Oyster shell, pulverized crab, and bone meal are also advised. In contrast to manure and compost, bone meal has the ability to moderate soil pH. All of these ingredients provide additional nutrients to the soil such as nitrogen, calcium, phosphorous, and potassium.

The process of putting the soil amendments starts with mixing the ingredients.  Some prefer the technique called double-digging. This technique simply involves the mixing of the ingredients and two depths of shoveled soil. Your new soil mix should be one-third to half of soil amendments.


When you dig a hole for your plant, make sure you create a drainage system near the roots. In the hole, create a cone-like mound of soil surrounding the roots of your roses. If you want to know how good your drainage is, pour water into a hole. In case it drains too fast, you may need to enrich your soil with additional amendments.


Air circulation is also needed in rose gardening. The right measurement allows them to get sunlight. You can water them easier as well. Spacing is not also for the knockout roses but also for you. You can maintain the roses without bumping into other plants; hence, destroying them.

If you want to make a hedge out of your roses, 30 inches is the best spacing measurement for you. On the other hand, 6 feet is best for climbing roses.

Companion Planting

Knockout roses are enough to please you as well as passersby. But if you want more colorful scenery in your garden, you may consider companion planting. Aside from that, some companion plants can help you deal with rose problems. Companion plants for knockout roses can be divided into flowering plants, herbal plants, and Alliums.

Marigold, yarrow, and lavender live well with knockout roses. Aside from adding colors whenever they bloom, these companion plants can aid in preventing pest infestations and promoting strong growth. Marigolds are beneficial in pest prevention while yarrows draw aphid-eating ladybugs. Lavender, on the other hand, deters hares and rabbits alike.

Planting roses with companion plants can help protect them from pests

It is also good to plant herbal plants as companions for your knockout roses. You will directly benefit from such plants in case you need treatment to some illnesses. Some of these herbal companion plants are nicely scented as well. Most of all, they deter pests. These plants include geraniums, thyme, and parsley.

Alliums are simply members of the onion family. Pests are discouraged to go near the onions and their neighboring plants because of their pungent smell. Just like the flowering plants, some Alliums also produce flowers that can help add colors to your garden. Alliums are disease-preventing companion plants as well. Leeks, Ornamental Alliums, chives, garlic are just a few examples of Alliums.

Rose Garden Maintenance

Some rose breeds can grow even without any human intervention. But if you want a more pleasant-looking garden, you need to observe proper care and plant maintenance. As a budding gardener, you will need to hone skills such as pruning and deadheading. You also need to know the proper way to water the plants as well as usage of fertilizer and mulch.


Pruning is simply trimming off the rose. This is done to shape the plant and enhance air circulation. Furthermore, pruning promotes new growth as well as blooming.

Early spring is the best time to prune your knockout roses. Take a look at their buds first. If these swell, then it signals pruning time. These red-colored swollen buds are as small as a sunflower seed.

Make sure you will be using clean, sharp pruners or hand loppers in this task. Start from the plant’s base. Cut evenly and make sure the cuts are ¼ inch above a bud. Get rid of worn leaves and weak stems as you prune.


If pruning is the cutting of stems and leaves, deadheading refers to the elimination of drying and dried flowers. This is usually done during summer but in the case of knockout roses, it must be done when the flowers start to form seeds.

The main purpose of deadheading is to encourage more blooms and re-flowering. It also removes potential hiding places of pests. Deadheading helps in energy conservation of the knockout roses as well.


Once-a-week watering is recommended for knockout roses. You should slowly and deeply water the plant by directing a hose or a watering wand on the roots. Knockout roses prefer soil that is soaked with water. Avoid the foliage when you water.  If you used insecticides, they may run off the leaves when you water the leaves.

You should remember to water your knockout roses only in early morning. This gives them time to dry. Don’t water them during afternoons and evenings.

Fertilizer and Mulch Use

Knockout roses can bloom more abundantly just with the use of fertilizer. You can opt for knockout rose food if you still want more flowers. When you shop for fertilizers, you should look for the three basic elements namely nitrogen, phosphorous, and potassium. Keep in mind the acronym “NPK”. You can choose from granular fertilizers to liquid fertilizers. However, do not apply too much fertilizer. This actually pollutes the soil, making it less suitable for plant life.

In addition to fertilizer, you may want to cover up your rose’s roots with mulch. If you want to be more eco-friendly and economical, you can opt for organic mulch. Straw, shredded leaves, grass clippings, compost, manure, and tree barks are examples of organic mulches. You may also use your stack of old newspaper as mulch. You can get straw, shredded leaves, and shredded or pulverized tree barks for your knockout roses.

While straws are best known for vegetable plantations, they can also be a good option for roses. It’s easy to get rid of them afterwards. These serve as home for the good insects as well.

If you want free-of-charge organic mulch, shredded leaves are there for you. You can get them from your garden. However, make sure they are not leaves from infected plants.

Tree barks are the most popular organic mulch for roses of all types. It’s because their color blends well with the soil. You don’t have to dig to apply them as well. You can simply spread on the base of your roses.

Before you use fertilizers and mulch, you must wait for a year after you planted your rose. Fertilize in spring or early summer but not on late summer. When you fertilize or put organic mulch, make sure your roses are watered first.

Dealing With Pests and Diseases

Black spot disease is common to other rose breeds before knockout roses were introduced. Radler’s rose is highly resistant to the disease. However, knockout roses are not exempted to pest infestation and other diseases.

Know how to identify common rose afflictions in order to act fast


Knockout roses can be troubled by plant pests such as caterpillars, aphids, Japanese beetles, rose chafers, leaf-cutting bees, and rose scales. These are the usual pests that damage the plants and annoy gardeners.

There are several species of caterpillars that infest roses but “Lozotaenia Forsterana” is the most well-known species. They feed on leaves and bore into buds. The results are shot holes in buds and flowers as well as chewed leaves.

The next one is the aphids or greenflies. These pests prefer the budding roses. That is why they abound during the seasons of spring and summer. They cause retarded growth and cease the budding of the flowers.

Popillia Japonica is the scientific name of “Japanese beetles”. Brought to the US in 1912, these insects were used to stop the uncontrolled growth and expansion of some plants. However, when those plants were managed, the Japanese beetles looked for other plants to infest. One of which is the knockout roses.

Rose chafers or Macrodactylus subspinosus are native to the US. These pests eat up almost all parts of a knockout rose such as the flowers, buds, leaves, and fruits. Expect them during the months of May to June.

The damages left by leaf-cutting bees are not as great as those of the other pests. They only cause irregularly shaped foliage. However, the sight of such is still annoying for most gardeners.

Rose scales (Aulacaspis rosae) affect the stems, petioles, and flower stalks of knockout roses. As a result, plant growth is stunted and the stems are flaky and crusted.

Pest Prevention and Solutions

There are other things you can do to stop pests from ruining your rose garden. Aside from companion planting, you may also do the pull-and-squish method. You may use horticultural oil, insecticidal soap, and spray as well.

Take time to visit your rose garden and observe the foliage every day. If you see chewed edges, that is a sign that pests are already present in your garden. You can do the pull-and-squish method if the damages are still minimal. The advantage of this pest solution is it doesn’t entail the use of harsh chemicals and it is free. You will only need your hands and eyes.

If you find it hard to spot pests, you can opt for insecticidal soaps, horticultural oil, fungicide, and pesticide sprays. The good thing about this is that there are more pests killed. However, frequent use of these pest solutions can harm the plant and the soil. These may kill beneficial insects too. Homemade pest solution is possible provided that you have clean spray bottles and the necessary ingredients.

Diseases and Their Treatment

One of the common diseases of roses is downy mildew. Signs include purple-colored spots bordered with yellow colors on stems and leaves. This will soon result to defoliation.

Downy mildew is not something to be worried about. It can be treated using a dormant spray. It also fades as the weather clears up. Pruning and garden sanitation are preventive measures against downy mildew.

Another rose problem is the powdery mildew. Downy mildew and powdery mildew are both fungal diseases. Fungicide can help treat powdery mildew.

A sign of powdery mildew is the powder-coated bud and leaf surfaces. However, there are severe cases that manifest powdery thorns and stems. This will result to deformed buds and leaves as well as plant growth retardation.

It still pays to know the cure for black spots in knockout roses. This is because your knockout roses are still prone to rust infection. Such rose problem has the same treatment as those of black spots. Neem oil and dormant spray can cure and prevent rust infection.

Orange spots on the leaves’ undersides are signs of rust infection. This usually strikes on cool nights. It will eventually lead to defoliation.

Viral Diseases

One example of viral diseases of roses is the Mosaic Virus. Unlike the aforementioned diseases, there is no known cure for this disease. You can see deformed knockout roses with mottling leaves. You may have no choice but to replace your affected rose but the good things is it won’t affect your other roses.

Another viral disease is the Rose Rosette Disease (RRD). Just like Mosaic Virus, the treatment for RRD is yet to be discovered. However, once your roses are infected, you don’t have any choice but to get rid of all your roses. RRD spreads unlike Mosaic Virus.

RRD makes a rose more vulnerable to winter damage. You can expect brittle and crinkled foliage too. The most prominent sign of RRD is the red pigmentation that is apparent to the stems, leaves, and flowers of the plant. The worst thing about RRD is that you may not be able to plant on the same spots where your infected plants were once situated. But if you still want roses in your home, you can try potted or hanged plants.


After you prune, deadhead, and treated your plants, gather the garden waste. Then, secure your garden waste in a garbage bag. Some may be used to fertilize the soil but if you are not sure whether they are from infected plants, it’s best to dispose them away.

Enjoying Your Roses

Rose gardening can be a difficult chore. However, it is considered as a rewarding one. A rose garden provides beautiful scenery which you can enjoy outside or while overlooking it inside your home. You can also harvest the flowers for display. You may share it to your loved ones too.

Flower Arrangement and Displaying

When you get the flowers, make sure your pruners are clean and sharp. This is to avoid damaging the canes. Prune after 3 pm because they are well-fed during this time. Don’t prune the fully blooming flowers but pick those that are just starting to open to partially opened flowers. Make sure your pruned flowers have a minimum of three leaves and these leaves must be located above the water line. In addition, you should have a bucket of water nearby.

Aside from pruners, you will also need sharp blades or rose dethorners, floral preservatives, bleach-and-water solution, and container (preferably vase). You can choose sharp blades as alternative to rose dethorners. You may take advantage of flower frogs as well though this is not that necessary.

Cut and arrange your own rose harvest

After pruning, soak the stems into cold water. Cut a small portion off the bottom of the stem of the roses before placing them in the container or vases. The floral preservative will prolong the life of your roses; re-cut them afterwards to further extend their shelf life. Change the container’s water with fresh water after a day or several hours.

Some tips in your flower arrangements:

  • Make an orange-colored flower stood out by mixing it with sunny knockout roses.
  • Gather various pastel-colored flowers and pale knockout roses and group them.
  • Mix bright red roses with pale ones with varying saturation.
  • Pick up your double knockout roses and display them together with crimson-colored flowers, more preferably other rose breeds.

Rose Colors and Their Meanings

If you plan to give your roses as gifts, you may want to know the meaning of the various colors. Aside from colors and their meanings, here are the best times for you to give these:

  • Pink signifies appreciation, gratitude, and love. You may give your pink knockout roses, blushing knockout roses, and rainbow knockout roses to say thank you. It’s best to give them during graduations or when you achieve something in your life.
  • If your rainbow knockout rose has overwhelming yellow color, you may want to give them to your sick loved ones. Yellow-colored roses signify your desire to wish them well. It also means delight and friendship.
  • Some knockout roses are white. White symbolizes spirituality, sympathy, innocence, and purity. That is why it is often used in weddings as the bridal flower. In addition to wedding ceremonies, it is also preferred for memorials.
  • Nothing beats the red roses in popularity. Aside from being a symbol of love, red roses are considered as religious and political symbols. The fieriness of the color signifies courage and youthfulness as well.

Blue and black roses are available these days, but unfortunately all blue roses and some black roses are just artificially colored. If you look closely, some black roses are not actually black, just really deep red. Black roses are used for memorials just like the white ones. Blue roses, on the other hand, are for those hoping for miracles such as love. Other rose colors include orange (symbol for enthusiasm and desire), lavender and purple (majesty and enchantment), and many more. The meanings of rose colors may vary due to their lightness or darkness too.