Knockout Rose Companion Plants, have several benefits they provide the plant. While Roses can be grown independently, growing companion plants around them give them a more luscious and fuller look.

Best Rose Companion Plants for Gardening

It is important to note that the type of plants you choose as companions for your Knockout Roses determines the overall look of your Rose garden. Let’s get into the best knockout Rose Companion Plants for your garden.

List of Knockout Rose Companion Plants

Roses are delicate and fragile plants. As a result, paying attention to the types of plants you grow with them is crucial, so placing the ultimate companion plants should be ones with very similar requirements. 

1. Baby’s Breath

Is it any wonder that baby’s breath plant can co-exist beautifully with the Roses in your garden when they pair perfectly with the Roses in flower arrangements? These white and sometimes pink flowers are the perfect rose companion plants, as they add the perfect soft aesthetic to your Rose bushes.

– Pairings

Baby’s breath plants, or gypsophila repens, are best paired with Rose plants with dark-colored flowers, like orange or pink. If you’re looking for what to plant with pink Knockout roses, baby’s breath is a great option. Remember that pairing them with roses gives off a beautiful contrast in the colors.

– Growing Season

There are several species of Baby’s breath, some of which are annual plants, while others are perennial flowers. The flowers bloom in the summer, from June to August, attracting butterflies and other harmless insects.

Baby’s Breath on a Wooden Table

These blooms last for many weeks, livening up the space in which they’re planted. Baby’s breath is best planted in early spring, ahead of the flowering season.

– Growth Requirements

Baby’s breath plants are easy to care for and grow. They require very little upkeep or maintenance as long as all their growth requirements are met. Baby’s breath flowers do well in sunny areas. However, they can adapt to places with a little shade for short periods.

It’s essential to consider the type of soil you have in your garden if you’re thinking about adding Baby’s Breath as a rose companion. Soils with good drainage and a slightly alkaline pH are ideal for planting baby’s breath. 

A quick soil pH test will go a long way in saving you from stress. If your soil is acidic, you can fix it easily by adding garden lime to balance the pH. You don’t need to worry about watering your baby’s breath daily, as they do well in dry soils.

2. Foxgloves

Foxgloves are tall plants with tubular flowers. There are different varieties of Foxgloves, most of which plants grow up to six feet in height, it is also called the digitalis purpurea. 

– Features

They are the perfect evergreens to plant with knockout roses for aesthetic purposes. Their tubular flowers, which come in different shades of yellow, white, pink, apricot, purple, and red, create a striking view when paired with the rose plant.

– Growing Season

Foxgloves are biennial and sometimes short-term perennial plants. Their flowers bloom between late spring and early summer. So basically this means you can have their blooms among your rose bushes between May and June.

The Colorful Foxgloves Flower in the Garden

– Growth Requirements

Foxglove companion plant is hardy and grows abundantly in zones four to 10. Like the Baby’s Breath Plant, Foxgloves require well-draining soils to grow properly. As long as the soil in your garden isn’t too dry or water-logged, your Foxglove plants stand a chance of surviving.

Foxgloves grow well in full sun or partial shade areas. Their light requirements vary in different climates. In cooler weather, they prefer the full sun, and in hotter temperatures, they prefer shaded areas. While Foxgloves do well in full sun, they might become stunted on prolonged exposure to the sun, so this is an aspect to fixate on.

Overall, note that as long as these growing conditions are met, foxgloves will thrive as companion plants in your rose gardens.

3. Breckland Thyme (Thymus serpyllum)

Breckland Thyme, also known as wild thyme and thymus serpyllum scientifically, creeping thyme, or elfin thyme, is an angiosperm in the mint family. It is indigenous to some parts of Europe and Northern Africa. 

– Features

Breckland thyme is a low-growing shrub. It has tiny evergreen leaves that grow up to eight millimeters long. It produces brightly colored flowers that grow in clusters.

The contrast between the heights of Breckland Thyme and the sunny Knockout Rose makes Breckland Thyme a perfect option for companion planting. Also, because of how close they grow to the ground, they can double as groundcovers for your rose garden.

Wild Purple Breckland Thyme

– Growing Season

Breckland Thyme can be planted during two separate periods of the year. It can be planted between March and May meaning in early spring to late spring and till September and November, which is autumn time.

– Growth Requirements

Breckland Thyme is easy to grow and maintain, as it can thrive in a variety of soil types. However, it grows best in lightly-packed soils that are well-drained. Breckland thyme should be grown in moist soil. It’s best to be careful about waterlogging the soil in a bid to make it moist, as these plants could become stunted as a result of root drowning.

The plant does well in full sun or lightly shaded areas. Breckland Thyme does fantastic in soils with neutral to alkaline pH. These will pair well with Knockout roses for your backyard garden, as both plants repel insects and most pests, hence they will keep the environment free of danger. 

4. Lady’s Mantle

Lady’s Mantle is a very interesting choice of Companion plant. It is the perfect border plant because of its shorter growing stems that will cover up the taller stems of your roses. They are the ideal addition to cottage gardens as they are elegant and low-maintenance.

– Features

The plant produces wide and scallop-shaped leaves with hardly noticeable greenish-yellow flowers in its season. The size of the flowers makes them a perfect addition to most bouquets. One interesting fact about Lady’s Mantle is that it was used as a medical herb in the past. Its leave and roots were boiled as tea to ease menstrual pain.

Dew Drop on Ladys Mantle Leaves

– Growing Season 

Lady’s Mantle, or alchemillia mollis, is a perennial plant with over 600 different species. They do well in hardiness zones between 3 and 8. The perfect time to plant them to yield maximum bloom is early spring or fall. Remember that you would need to exercise a certain level of patience with these plants, as they may take a while to grow for the first time.

– Growth Requirements

Lady’s Mantle will do well in partially shaded areas. Although it can be planted in full sunlight, it must be monitored. In additio, note that it would grow in almost any soil type as long as it is well-drained and not flooded with water.

5. Shasta Daisy

Like its name, Shasta Daisy looks like a daisy, however is also known as the Leucanthemum x superbum. 

– Features

It has an arrangement of white petals surrounding a large yellow bud, much like how a daisy looks. The Shasta daisy is a favorite garden plant because of its bright white and yellow colors. As a result of how simple they look, they pair well with the bolder petals of Knockout Roses when they are in the same garden together.

Shasta Daisies in Blossoms

– Growing Season 

Shasta Daisy are perennial flowers, and they grow and flower during summer meaning between the months of July and September. They grow well in hardiness Zones four to nine.

– Growth Requirements

Shasta Daisy requires very little maintenance. These plants prefer to stay in full sun to partial shade for optimum growth, hence they bloom in summer. If you desire brilliant white petals with yellow centers, plant the flowers in full view of the sun or under a little shade in extremely hot weather.

It’s crucial to pay close attention to the soil and ensure that it is well-draining and its moisture content is not too much.

6. Snapdragons

Snapdragons are popularly known as dragon flowers or dog flowers, and scientifically they are also known as the antirrhinum. 

– Features

They are known as dragon flowers because their flowers look like the mouth of a dragon. These dragon mouth-shaped flowers are suitable companion plants for knockout Roses because of the impressive contrast they add to the landscape. Snapdragon blooms come in various colors that are suitable to be paired with different shades of Roses. 

Close View of Beautiful Snapdragons

– Growing Season

Snapdragons grow well in cool weather and reach peak bloom season in early spring through fall. The flowers bloom in such a way that there’s always a pop of color somewhere on the stem all through fall, in contrast with Roses that go inactive during this period.

– Growing Conditions 

It’s best to grow Snapdragons in rich, well-draining soils with a neutral or alkaline pH. The plants require full to partial shade and require more water than other perennials.

7. Sage (Salvia officinalis)

Sage is another plant to consider when thinking of plants to pair with your roses, because these plants are the perfect evergreens to plant with knockout roses. 

– Features

They are shrubby perennials, and they have characteristic greenish-grey leaves that produce blue and sometimes purplish flowers. In addition, their flowers are mostly ornamental.

Blooming sage Flowers in Garden

– Growing Seasons

The best time to plant sage is during the cooler seasons, which are spring or fall, especially after the threat of snow has passed.

– Growth Requirements

It’s best to grow Sage in full view of the sun. However, a little shade will be best when the weather gets too hot. The plant grows well in sandy or well-drained loamy soils. Note that sage does not do well in water-logged soil, so be careful when watering your plant. Soils with slightly acidic or neutral pH are also best for planting sage.

8. Parsley

Parsley is usually grown as a herb, so it might be the last thing on your mind when considering companion plants. 

– Advantageous Companion Plant

However, these low-growing foliage plants are perfect companions for Knockout Roses foundation planting. You can get a two-in-one benefit from growing Parsley and Roses together. On the one hand, you get a herb you can use in your kitchen; on the other hand, you add to the aesthetics of your garden.

Evergreen Parsley Herb in Garden

Additionally, it has a fantastic scent that can boost the smell of your garden, as knockout roses don’t particularly have a strong scent.

– Growing Season

Parsley is an annual plant. It grows well during spring until winter comes.

– Growth Requirements

Parsley requires full to partial shade for optimum growth. The soil has to be nutrient-rich and moderately moist with a slightly acidic pH for the plant to grow without problems. For best results, you should mix compost with the soil throughout its growing season.


Knockout Roses can be grown on their own. However, growing them alone might leave your garden looking bland and uninteresting. In this article, we’ve provided eight companion plants that you can choose to add to your rose garden.

Just keep these in mind:

  • You need to pay close attention to your soil type, pH, and moisture content in order to grow the perfect companion for your roses.
  • You can choose companion plants that will complement the color of your knockout Rose and maybe even be beneficial to them by throwing off the pests in the air.
  • Pay attention to the planting seasons, because you want them to thrive together.

Now that you know the most amazing companions, so with all these options, what are you going to be planting next to your stunning roses? 


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