Red Double Knock Out® Rose

Rosa 'Radtko'

4 Reviews

Red Double Knock Out® Rose

Rosa 'Radtko'

4 Reviews

This product is currently out of stock and unavailable.


How are the heights measured?

All tree, and nothin' but the tree! We measure from the top of the soil to the top of the tree; the height of the container or the root system is never included in our measurements.

What is a gallon container?

Nursery containers come in a variety of different sizes, and old-school nursery slang has stuck. While the industry-standard terminology is to call the sizes "Gallon Containers", that doesn't exactly translate to the traditional liquid "gallon" size we think of. You'll find we carry young 1-gallons, up to more mature 7-gallons ranging anywhere from 6 inches to 6ft.

How does the delivery process work?

All of our orders ship via FedEx Ground! Once your order is placed online, our magic elves get right to work picking, staging, boxing and shipping your trees. Orders typically ship out within 2 business days. You will receive email notifications along the way on the progress of your order, as well as tracking information to track your plants all the way to their new home!

Why are some states excluded from shipping?

The short & sweet answer is: "United States Department of Agriculture Restrictions." Every state has their own unique USDA restrictions on which plants they allow to come into their state. While we wish we could serve everyone, it's for the safety of native species and helps prevent the spread of invasive disease & pests. We've gotta protect good ole' Mother Nature, after all.

About Me


The Double Knockout Rose is covered with beautiful fully-double flowers in a stunning fire-engine red color. It comes into bloom around the end of May and will still be blooming when the first frost hits it – three seasons of bloom. It forms a full bush up to 4 feet high and as much across. Unlike other roses it is resistant to black-spot and most other rose diseases.

  • Large and brilliant bright-red blossoms
  • Real rose form on a tough and easy bush
  • Continuous bloom from May to frost
  • Drought and heat resistant
  • Disease-resistant so always beautiful

Right across America, from the north to Florida and California, this rose has taken the garden world by storm. It is happy in all kinds of soil and needs just the most basic care. If you only grow one rose, this is the one to grow. Whether you plant it as a gorgeous specimen, or make a beautiful row of them along your drive, property line or around your terrace, this rose will bring color and joy to every garden.

Plant Hardiness Zones 5-10
Mature Width 3-4
Mature Height 3-4
Zones 5-10

When it comes to growing roses, despite their great beauty they have a reputation for being difficult plants to grow. Many roses need lots of skilled-care, are subject to pests and diseases and are very particular about soil and climate. If that is how you feel, then the Double Knockout Rose will change your mind; it is as easy to grow as a plant can be. It requires only the most basic care and is hardy across a whole range of climates and soils. The Red Double Knockout Rose will reward you with three seasons of stunning rich-pink blooms that will light up your garden and have your friends congratulating you on your ‘green thumb’.

You can plant Red Double Knockout Roses all over your garden, among shrubs or flowers, in a group or a row. Use it wherever you want three seasons of fabulous, trouble-free color. This vigorous plant will grow to its full height of around three feet in just a few weeks in spring, and then continue to bloom until frost.

Most roses are subject to a long list of problems. They start off well in the spring, but rapidly the leaves begin to turn black and fall off (black spot), or become covered in white powder (mildew) or black blisters (rust). Not the Knockout Rose – it knocks those diseases right out with its amazing resistance which is the result of years of careful breeding. Like other roses it may attract a few insect pests, but it is so hardy and vigorous that you will not even notice them. They will be ignored by your Knockout Rose as it blooms away all summer.

Growing Red Double Knockout Roses

Double Knockout Rose forms a bush 3 to 4 feet tall and 3 to 4 feet across, or even more in milder areas. It has healthy, glossy leaves right to the ground, and the large, rich red flowers float over the foliage all spring, summer and fall. The base has numerous woody twigs which store the strength needed to throw up many strong new sprouts in spring as the weather begins to warm. The flowers are produced continuously and unlike other roses, when they die they just fall off, leaving the plant constantly fresh and clean.


Double Knockout Rose is hardy in zones 5 to 10, so it will grow in all but the coldest states. Even in zone 4 it will survive if just before the first snow-fall you take a bucket, cut out the bottom, put it over your plant and fill it with dry peat moss. Remove it when the snow has gone and your Knockout Rose will be alive, happy and ready to go.

Planting and Initial Care

Your Double Knockout Rose will do best is a sunny location and should not get completely dry. It will easily handle regular summer conditions, but not drought. It will grow well in all kinds of soils, including heavy clays.

Because the Double Knockout Rose grows so strongly all the time, it will benefit from plenty of organic material, such as compost or rotted manure, dug into the ground where you are planting it. You need to feed that vigorous growth with rose food, which should be added when planting, and again each spring and in mid-summer. Dig a wide hole and put your rose in to the same depth as the container. Put back most of the soil, firm it down well and fill the hole with water. When the water has drained away, put back the rest of the soil. For planting in groups or in a row, place the plants 18 inches to 2 feet apart.


Each spring, before the new growth starts, cut back the stems to 6 to 12 inches above the ground. Cut out any weak or old stems. Not only does this encourage the strong growth that will produce all those flowers, but it protects against diseases and pests.

History and Origins of the Red Double Knockout Rose

The original Knockout Rose took the gardening world by storm when it was introduced by rose breeder Will Radler. He had worked for years to make a rose that was disease-resistant and so hardy it would grow in all climate zones. His original variety won the coveted All-America Rose Selections prize in 2000. This prize is not just awarded on looks, but on the results of growing the rose in gardens all across the country – so it has to be good. Literally millions of plants of this rose were sold across America every year – more than any other rose – and millions of gardeners can’t be wrong.

But the first Knockout was a single rose with just a few petals, so Will went back to work and bred the Double Knockout Rose, with up to 24 full red petals creating that classic ‘rose’ look. Not only were the flowers so much fuller, the plant was just as disease resistant and even hardier than the original.

Buying Red Double Knockout Roses at The Tree Center

Double Knockout Rose is such a special plant that it is protected by patent. So it must be produced directly from trees absolutely known to be right. Our trees are grown the correct way, from grafts of these special trees. That way every tree is identical to the original. However these take longer to produce, so avoid other cheaper roses that will only be a disappointment. If it doesn’t say ‘Knockout’ it isn’t the amazing Double Knockout Rose.

We sell only trees that are true to the original form and we have a wide range of sizes to give you the best plant for your purpose. However, we are constantly renewing our stock so our customers get fresh, healthy plants, so supplies of this tree may be limited. To avoid disappointment order now or check out other unique varieties from the series, like the Double Pink Knockout Rose and the Pink Knockout Rose.

Back to top

Red Double Knock Out® Rose

Rosa 'Radtko'

4 Reviews