7 Best Knockout Rose Companion Plants (With Photos)

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By Arthur Mbanefo

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Knockout Rose is known for being nearly impossible to please with other plants. So, when landscaping with these roses, there isn’t much room for mistakes. 

This is why most gardeners have the complete knockout rose companion plants checklist memorized. 

Because one wrong invitee and your rose will be tormented to death. 

But don’t despair if you are clueless about the pairing plants.

Just follow my lead! 

7 Best Knockout Rose Companion Plants

If homeowners were to choose just one out of the dozen species of roses for their landscape, it would likely be the Knockout rose. 

They are one of the lowest-maintenance and last-longing bloomers. 

Knockouts are also the most pest and disease-resistance roses. And are remarkably immune to black spot disease —the scourge of rose growers.

However, they are sensitive to surrounding plants. And I was a victim of this —pairing fuchsias with Knockout rose. 

This shrub is undeniably attractive. The bold hanging blooms and drooping growth complement my rose cups.

However, like most hydrangeas, they require lots of shade and moisture —two unbearable conditions for roses. 

It made my Knockout rose to suffer a lot!

Not after I made an in-depth entry about the knockout rose companion plants were my rose able to socialize. 

Some of the pairs I tried were coneflowers, Shasta daisies, delphinium, and other classic cottage plants. They are complementary to my Knockouts and have formed a good partnership. 

Let’s look at a  few more others (in detail) and why they work SO well with knockout roses: 

1. Lady’s Mantle

Another knockout rose companion plant is the Lady’s mantle. 

This Alchemilla mollis can quickly grow and thrive in different soils and conditions. 

This dang leafy plant might seem old-school, but it still has a place in the ornamental garden due to its stunning foliage. 

The Lady’s mantle forms a great bond with the rose since it adapts to full sun and shady areas in hot climates. 

The scallop-shaped leaves with greenish-yellow flowers make this plant an absolute beauty.

And you can grow them as border plants since they are elegant and low-maintenance, and the short-growing stem will sometimes shade your roses. 

But generally, their profile suits any cottage garden. 

2. Sage

Sage brings a lot to the table —even more than it is appreciated. 

The contrast of the oval greenish-grey leaves that is wrinkled and downy adds qualifies it as a knockout rose companion plant, let alone the showy blue and purplish flowers. 

Aside from the flavors and several promising health benefits it brings to your recipes; sage attracts the interest of beneficial insects.  

Pollinators like honey bees and butterflies are drawn to the blooms, while the robust and intense fragrance drives away unwanted pests.  

They also work well with other Mediterranean herbs, like thyme, with similar dry and free-draining growing conditions. 

And the best time to sow sage is in spring or fall, after the pass over of frost. 

3. Shasta Daisy

You can not count the Shasta Daisy out! They sit prevalently amongst the most noticeable flower. 

Furthermore, they are deer and drought-resistant perennials that shine throughout your garden. 

The brilliant white petals and yellow center pop of fresh, vibrant summer hues attract butterflies and other pollinators. 

However, the best time to plant them is early spring or summer. While this Daisy is little maintenance, you MUST pay attention to the soil. 

A rich, well-draining, and moist soil is the perfect breeding ground. 

Don’t worry. They thrive in both full sun to partial shade but boom in summer. 

4. Snapdragons

Snapdragons are short-lived perennials famous for their bright colors. 

They are favorites to classic cottage gardens and much appreciated standing beside the knockout rose. And they have long-lasting blooms.

Snapdragons have infinite uses –from edible flower boxes to mixed border gardens to patio containers. 

Hence, you can’t go wrong with this beauty. 

They bloom at the bottom of the stalk with intensely saturated color, then work their way up, making them stand out in any garden.  

5. Parsley

If you grow a lot of herbs in your garden for garnish, condiment, food, and flavoring, Persley is one you can consider occupying those spaces between your knockout rose. 

These low-growing foliage herbs benefit your culinary uses and add aesthetics to your roses. 

Parsley isn’t a fancy plant. However, the aromatic scent is a repellent to harmful bugs. 

Hence, parsley serves as a watchdog and  KEEP-OFF warning sign while boosting the smell of your garden. 

Moreover, it takes almost nothing to grow this herb. They require nutrient-rich and moderately moist soil with a slightly acidic pH. 

You can mix compost throughout the growing season for better yield. And they appreciate the partial shade your knockout rose provides. 

6. Breckland Thyme

You can call it elfin thyme or creeping thyme. But this member of the mint family is a low-growing shrub of about eight millimeters long with evergreen leave. 

They produce little showy flowers in clusters that can complement your rose. 

The contrast between both heights is also refreshing to see. And because they grow so low to the ground, they can double up as groundcovers for your Knockout rose. 

In addition, they appreciate fun sun like roses do but can thrive in lightly shaded areas. Soils with neutral to alkaline pH favor them the most. But it should be well-drained and moist soil.  

Avoid waterlogging by all means possible, as it results in root drowning and rot. 

But the best time to plant your thyme is early to late spring (March to May) and autumn (September and November).

7. Baby’s Breath

The baby’s breath plant can also co-exist with your knockout rose. 

They are the perfect filler for cottage gardens, doubling as flowering mulch and preventing weeds from overcrowding other plants. 

They offer several flushes of bloom-attracting pollinators from late spring to fall. 

And like roses, they crave at least six hours of sunlight each day while resting on well-drained soil. 

The pairing of both plants MUST be organized to match your garden’s aesthetic. 

But I have noticed the baby’s breath pairs best with dark-colored Rose flowers, like pink or orange.  

So if you are tagging this plant along with knockout roses, the species should come in a dark hue. That way, the contrast will be more profound.

Frequently Asked Questions

What Is The Most Beautiful Rose Type?

Roses are among the most beautiful flowers that evoke romance, love, and affection. 

There are way too many species of roses to count, and all are beautiful. 

However, some of the MOST beautiful rose with standout elegance are:

  • The Victor Hugo Rose.
  • The Winchester Cathedral Rose.
  • The Michelangelo Rose.
  • The Gold Medal Rose.
  • The Black Baccara Rose.
  • Rose By Sara Verdier.

What Is The Rarest Color Of Rose?

Have you ever seen a blue rose? 

That sh*t is SO rare! It is the rarest color of the rose because it wasn’t a naturally occurring rose. 

It has to be created through genetic engineering. 

Due to its genetic makeup, significance in the flower world, and rarity, it will definitely cost you an arm and a leg. 

And ordering a bouquet can be challenging as only few florists can access this mysterious flower. 

What Color Roses Smell The Strongest?

The scent might transport you to sweet memories of love and romance. 

There is a saying that “Stop Rushing Through Life…Take Time To Smell The Roses… Life is too Short Not to!”

And it is SO true! 

They are one of the most luxurious fragrances. A scent might transport you to a dream world of love and romance. 

Sadly, not every species of rose has that enchanting and long-lasting fragrance. 

But here are the few with the strongest scents:

  • Rose St Ethelburga
  • Rose The Generous Gardener
  • Rose Boscobel
  • Rose rugosa Roseraie de l’Hay
  • Rose Charles de Mills
  • Rose Compassion
  • Rose ‘Desdemona’
  • Rose ‘Francis E. Leicester’
  • Rose ‘Ambridge Rose
  • Rose ‘Golden Celebration
  • Rose ‘The Poet’s Wife
  • Rose ‘Kew Rambler
  • Rose ‘Lady Emma Hamilton 
  • Rose ‘Munstead Wood
  • Rose ‘Paul Noël’
  • Rose ‘Strawberry Hill’
  • Rose ‘The Country Parson’
  • Rose ‘Wallerton Old Hall’
  • Rose ‘Honey Perfume’ 
  • Rose ‘Fragrant Plum’ 
  • Rose ‘Harlow Carr’
  • Rose ‘Gabriel Oak’ 
  • Rose ‘Gertrude Jeckyll’

NOTE: All of the robust blooms rose has a lot in common. They have more petals—the more the petals, the more substantial the smell. 

Thicker petals tend to contain more fragrance. That is just how it is. 

But in general, darker-colored roses tend to have more fragrant than lighter ones. 


Other knockout rose companion plants include Lavenders, Marigolds, Alliums, Verbenas, and whatnot. 

But most homeowners generally avoid the drama of pairing their roses. They let their Knockout roses live in peace ALONE, which is totally understandable.

However, a stand-alone rose looks bland. But experiencing your space with a couple of companion plants adds contrast and gives your landscaping idea a voice.  

NOTE: You have to pay close attention to the color of your Rose and choose respectively. 

Also, your soil type, pH level, and moisture content play a significant role. Timing is crucial, too –especially during the planting season because you want them to thrive together.