Are Knock Out Roses Amazing Shrubs or All Hype?

You’ve probably noticed the prevalence of Knock Out roses. They are a landscaper favorite and have popped up everywhere, from your neighbor’s yards to your local strip mall, and even your dental office’s parking lot. 

These tough, low-maintenance shrubs are the most popular roses in America. However, some rose fans argue that they’re not really roses at all. Why all the fuss?

While popular, their overuse has made some enemies. Whether appreciated for their ease of care and long bloom season or hated for their lack of fragrance and ubiquity, Knock Out roses always spark discussion in the rose-growing community.

Before you snag a Knock Out rose from your garden center, let’s learn about them and evaluate whether they’re the best choice for your landscape. In this article, I’ll explain some pros and cons of growing Knock Outs, offer some alternatives, and give you my opinion on the debate.

About Knock Out Roses

Knock Out roses are perennial woody shrubs that bloom in flushes from spring through frost in USDA zones 5-11. They began in the basement of hobby hybridizer William Radler in the 1970s. Radler was a big rose fan but was unsettled by the chemical spray regimens used by the industry and many home gardeners. 

With the goal of making an eco-friendly rose that would be resistant to disease, cold hardy, and healthy without sprays, he worked for 15 years to develop seedlings.

In 1989, after extensive research and trials in his Wisconsin garden, Radler achieved his goal of making an easy-care, environmentally friendly rose. 

Knock Outs were durable, hardy, and bloomed throughout the summer season. They didn’t need the pampering and chemical interventions common to the most popular roses of that time, the hybrid teas.

Since their Star ⓇRoses and Plants nursery debut in 2000, Knock Out roses have risen in popularity and expanded to a variety of colors and bloom forms. These vigorous shrubs come in single and semi-double flowers, and colors ranging from white to bright red, with pinks, yellows, and multicolor varieties in between.

So, what’s not to love? Let’s explore the pros and cons of these hotly debated shrubs.

Pros & Cons

Here’s a quick look at the pros & cons of planting Knock Out roses in your garden. While these popular roses can be absolutely stunning in the right garden setting, their more aggressive growth habits can make them a turn off for some gardeners.

Why Gardeners Love Them

 Knock Out roses earned the Earth-KindⓇ designation for offering an environmentally responsible blooming shrub to gardeners. Unlike fussy hybrid teas, they don’t need complicated spray regimens to perform. In fact, many growers say they grow in the poorest of soils and conditions, and still bloom all summer!

This type of rose is easy to find. In fact, they are so heavily marketed and stocked by retailers that they are sometimes the only roses on offer!

Landscapers love to use them en masse or as long hedges in corporate environments because they provide lots of color for little effort. Less watering and pampering are appealing to the home gardener as well.

When looking for a new shrub for the home garden, they provide a colorful, long-flowering option that provides more interest than your average green foliage.

In addition, gardeners who’ve been timid in trying out roses due to their reported fussiness can have growing success. They might then be tempted to explore more varieties, and that’s always a good thing.

Why Some Gardeners Avoid Them

What could be the problem with an eco-friendly, easy-care rose? Well, depending on who you ask, quite a lot. Some gardeners complain that Knock Outs don’t look like real roses. Their loose blooms shatter easily and don’t hold up in the vase. They don’t have the luscious, intoxicating smell we love.

Another is that the marketing for this type of rose has been a bit misleading. While they are drought-tolerant and black spot resistant once established, they are not disease free. They are still susceptible to many insect and disease problems. Knock Outs struggle with infestations of Japanese Beetles and Rose Slugs and can also be prone to powdery mildew.

They also need maintenance to look good. Unless you like the look of brown, withered blooms, they need deadheading. Without pruning, they can grow to an ungainly size. They need fertilization to produce the expected swath of blooms.

Though the species are not themselves responsible for the deadly Rose Rosette Disease, their wide use and treatment have contributed to its spread. When treated as a plant-it-and-forget-it species, Rose Rosette’s symptoms are left unnoticed.

Worse, landscapers inexperienced with roses shear the bushes and blow infected debris into surrounding areas. When planted en masse and not often inspected, the disease spreads easily, killing the Knock Outs and infecting other roses nearby.

Their popularity and overuse have stolen the spotlight from many heirloom roses with unique beauty and history that are just as hardy, disease-resistant, and easy care.

When Knock Outs become all that we buy, stores stop carrying more unique varieties. Thus, the prevalence of this type of rose leads to difficulty finding and preserving beautiful roses that will thrive just as easily, without the uniform parking-lot look.

Knock Out Rose Alternatives

Whether you love or hate them, it’s important to know that Knock Out roses aren’t the only easy-care varieties available. If you want something just as tolerant and hardy, with a bit more unique appeal, consider one of the following varieties.

This list is just a tiny sample of easy-to-grow roses. If you don’t see one that speaks to you, there are hundreds more that might! Always look at the recommended growing zones to ensure that they will thrive in your area.

‘Easy on the Eyes’

	botanical name Rosa ‘WEKswechefy’
	plant type Perennial
	sun requirements Perennial
	height Perennial
	hardiness zones 5 to 9

‘Easy on the Eyes’ is floriferous, beautiful, and disease-resistant. This member of Weeks Roses’ Easy to Love collection is a winner for beginner gardeners. ‘Easy on the Eyes’ is an attractively rounded shrub, with lavender-pink, wavy petals that have a deep purple center and golden eye.

‘Easy on the Eyes’ makes a great cut flower, and has a lovely citrus and spice scent. It’s vigorous, healthy, and requires no sprays or pampering to shine.

‘Iceberg’

	botanical name Rosa ‘KORbin’
	plant type Perennial
	sun requirements Full Sun
	height 4- 12’
	hardiness zones 4-10

‘Iceberg’ an all-summer white rose bloom machine, is one of the world’s most popular roses. This rose is effortless and more cold-hardy than Knock Outs, making it a great option for northern gardeners.

‘Iceberg’s’ bloom quantity, health, and adaptability won it the Royal Horticultural Society’s Award of Garden Merit for its quantity of blooms and adaptability. If you want more color, check out ‘Burgundy Iceberg’.

‘The Fairy’

	botanical name Rosa ‘The Fairy’
	plant type Perennial
	sun requirements Full Sun- Part shade
	height 2’ –4’
	hardiness zones 5-11

‘The Fairy’ is also an Earth-Kind Ⓡ landscape rose that grows quickly to form large blankets of color or a pretty hedge.  A hardy polyantha, this rose has an abundance of tiny pink pompon flowers in abundant sprays all summer.

It’s hardy, cold-tolerant, and no fuss. Lean in close for a sweet apple scent.

‘Suñorita’

	botanical name Rosa ‘Chewgewest’
	plant type Perennial
	sun requirements Full Sun
	height 3’ – 4’
	hardiness zones 5- 9

This easy-to-grow multicolor rose was Proven Winners 2022 Rose of the Year.  The cheerful blooms of ‘Suñorita’ begin orange and fade to shades of yellow, apricot, and pink. ‘Suñorita’ received the American Rose Society’s Award of Excellence for outstanding disease resistance and repeat bloom.

Sunorita has a tidy mounding habit and black spot resistance. It performs especially well in humid climates. 

‘Marie Daly’

	botanical name Rosa ‘Marie Daly’
	plant type Perennial
	sun requirements Full Sun-Part Shade
	height 3’-4’
	hardiness zones 6-11

‘Marie Daly’ is a super tough polyantha rose that will defy even the most inept of gardeners with all-season blooms. It has clusters of soft mauve-pink rose flowers and a lovely musk fragrance.

Another recipient of the Earth-Kind Ⓡ designation ‘Marie’ resists spider mite problems and doesn’t need sprays to look its best. This rose can also handle some shade. Best of all, ‘Marie’ is nearly thornless!

‘William Baffin’

	botanical name Rosa ‘William Baffin’
	plant type Perennial
	sun requirements Full Sun
	height 7’-10’
	hardiness zones 2- 9

Knock Outs are far from the hardiest roses around. In fact, there are a huge variety of roses that are cold hardy down to -30 or even -50 ℉! Check out ‘William Baffin’, part of the reliable and tough Canadian Explorer Series, resistant to both blackspot and mildew.

This multi-award winner is a vibrant strawberry pink with a yellow eye. It wows with constant semi-double blooms all summer, and pretty red hips to provide winter interest. 

‘Emily Carr’

	botanical name Rosa ‘Emily Carr’
	plant type Perennial
	sun requirements Full Sun
	height 3’-4’
	hardiness zones 3 – 9

“Emily Carr’ is a head-turning classic red rose, disease-resistant and dependable to zone 3. Part of the Canadian Artist series, this rose has a nice, upright growing habit.

‘Emily’s’ constant blooms are beautiful in the vase. She’ll produce lovely, semi-double deep crimson roses all summer long.