There are many rose varieties you can grow, most of which need a lot of maintenance. But there’s one that requires minimal maintenance: Knock Out roses. These are gorgeous, bright, and colorful roses, with blooms coming back year after year. As one of the most popular flowers in the world, Knock Outs are loved for their beautiful blossoms and relatively carefree nature.
Knock Out roses also need companion plants to thrive like many other plants. Companion planting is an easy way to boost the health and productivity of your prized Knock Out roses in your home garden. It’s also a natural way to create a beautiful, healthy, and thriving garden.
We’ll touch on several companion plants for Knock Out roses in this handy guide. Besides the best companion plants for Knock Out roses, we’ll take a sneak peek into some plants you should never grow with these roses. So, stick here to learn more!
The 12 Great Companion Plants for Knock Out Roses
Flower Companions
1. Marigolds
| USDA Hardiness Zone: | 2 – 11 |
| Best Soil Type: | Moderately fertile well-draining soil |
| Soil pH: | Between 6.2 and 6.5 |
| Sunlight Exposure: | Full sun |
| Required Growing Temperature: | 64 – 68°F (18°C – 20°C) |
Marigolds help deter pests from your rose garden. They also have the bonus of being edible! As it grows, the marigold spreads to create an edible garden with flowers, foliage, and seeds. They grow well in hot summers but can also do well in cooler areas.
Marigold flowers also attract bees, which help pollinate plants like Knock Out roses. Besides, Knock Out roses and marigolds share similar conditions of growth. You just need to keep the soil moist until established. Then, water it once a week.
The beautiful orange, golden, and yellow marigold hues bring more life to your Knock Out roses.
2. Pincushions
| USDA Hardiness Zone: | 4 – 8 |
| Best Soil Type: | Well-draining soil |
| Soil pH: | Between 7.0 and 7.5 |
| Sunlight Exposure: | Partial sun or shade, but ensure they receive full sun for some time during the day. |
| Required Growing Temperature: | 50°F – 75°F (10°C – 24°C) |
Pincushions are often used as ground cover. They provide excellent support for Knock Out roses. They also have a low-growing mounding growth habit with small leaves that stay green all year. Their many colors will complement your Knock Out roses well.
You can prune pincushions in spring before they bloom to promote branching and keep them from getting leggy as they get older.
Both flowers work well at attracting pollinators. Besides, pincushions need minimal maintenance, similar to Knock Out roses. Simply water them often until the roots get established. You’ll have it easy if you grow these two plants together.
3. Alyssum
| USDA Hardiness Zone: | 9 – 11 |
| Best Soil Type: | Loamy and rich soil |
| Soil pH: | Between 6.5 and 7.3 |
| Sunlight Exposure: | Full sun or partial shade |
| Required Growing Temperature: | 50°F – 79°F (10°C – 26°C) |
Alyssum varieties include the white, pink, and purple cultivars. They all enhance the roses’ growth, with the colors making the Knock Out rose garden a real eye-catcher.
In other words, alyssum forms a dense carpet of flowers in your rose garden. They also attract pollinators to your garden, not to mention their honey-like fragrance.
These flowers also do a lovely job of keeping the area from getting too weedy. It’s particularly effective when planted in fall or winter. Maintenance involves watering every week; ensure the soil is moist but not soggy.
4. Baby’s Breath
| USDA Hardiness Zone: | 4 – 9 |
| Best Soil Type: | Ordinary garden soil, but don’t fertilize the soil. |
| Soil pH: | Between 7.0 and 7.5 |
| Sunlight Exposure: | Direct sunlight |
| Required Growing Temperature: | 59°F – 77°F (15°C – 25°C) |
Baby’s Breath is a perennial flowering plant. Its common name comes from its white feathery plumes that resemble a baby’s breath. It is a beautiful addition to any garden, including those with Knock Out roses.
The white or soft pink flowers produced by the Baby’s Breath complement Knock Out rose flowers well. The pink flower is also a favorite for weddings. You can use it as a filler in bouquets.
Both plants can grow in similar conditions. That means they don’t need too much maintenance to thrive. You just have to water the Baby’s Breath well before transplanting to your Knock Out rose garden.
5. Foxgloves
| USDA Hardiness Zone: | 4 – 9 |
| Best Soil Type: | Any well-draining and moist soil type |
| Soil pH: | Between 5.5 and 6.5 |
| Sunlight Exposure: | Full sun or full shade |
| Required Growing Temperature: | 64°F – 68°F (18 – 20°C) |
The foxglove is an herbaceous perennial with brightly colored flowers. Usually, it isn’t found at most nurseries because it’s considered invasive in some areas. However, it makes an excellent companion for Knock Out roses because of its tall and beautiful flowers.
Foxgloves also deter deer and rabbits. It makes them perfect for those areas where deer and rabbits are prevalent!
Ensure you don’t ingest any part of the foxglove plant because it’s poisonous. Besides, don’t grow it if you have pets that prefer feeding on garden plants. Maintenance involves watering during the dry season only. Ensure the plants don’t get soaked for long.
6. Snapdragons
| USDA Hardiness Zone: | 7 – 11 |
| Best Soil Type: | Well-draining and rich soil |
| Soil pH: | Between 6.2 and 7.0 |
| Sunlight Exposure: | Partial shade |
| Required Growing Temperature: | 40°F–80°F (5°C – 27°C) |
Snapdragons are perennial flowers that can grow up to 3 feet tall. Their large flowers come in different colors, blooming from mid-summer to early fall. They’re also called dragon flowers and snapdragons because of their long thin petals resembling dragon tails.
Snapdragons are excellent at filling the gaps left by Knock Out roses in your garden. Their brightly-colored flowers give your rose garden a bright flowery display.
Snapdragons are versatile in their uses- you can use them for ornamental and culinary purposes. The flowers are edible and used in salads or soups for extra flavor.
These flowers will need only an inch of watering every week if there’s no rainfall. Water close to the plant’s crown.
Herb Companions for Knock Out Roses
7. Lavenders
| USDA Hardiness Zone: | 5 – 9 |
| Best Soil Type: | Well-draining sandy soil |
| Soil pH: | Between 6.5 and 8 |
| Sunlight Exposure: | More than six hours of direct sunlight a day |
| Required Growing Temperature: | 68 – 86°F (20°C – 30°C) |
Lavender is a perennial herb also used as an ornamental plant. It has lovely purple flowers and a strong scent. It needs little maintenance, and you can grow it anywhere in your garden.
Lavender is an excellent choice for planting near Knock Out roses. Its fragrance discourages aphids from feeding on your roses. Besides, lavender produces nectar that attracts beneficial insects like bees and butterflies to pollinate your Knock Out roses.
The lavender plant also deters deer and rabbits that can feed on your Knock Out roses. The two plants thrive well when grown together as both need full sun and watering well after planting.
8. Sage
| USDA Hardiness Zone: | 4 – 11 |
| Best Soil Type: | Well-drained loamy and sandy soil |
| Soil pH: | Between 5 and 7.5 |
| Sunlight Exposure: | Medium to full sun |
| Required Growing Temperature: | 70°F (21°C) |
Sage is a perennial plant with small lavender-colored flowers that bloom at the end of summer. It attracts pollinators like bees, hummingbirds, and butterflies to your Knock Out roses.
Its most important feature is its ability to repel aphids and beetles from feasting on your Knock Out roses. These features make it an excellent companion plant.
You can plant sage near your Knock Out rose bushes as long as they aren’t subject to strong winds. The best way to grow sage is as a border plant, but you can also plant it inside your garden with Knock Out roses. Water only when the soil is dry.
9. Creeping Thyme
| USDA Hardiness Zone: | 4 – 9 |
| Best Soil Type: | Well-draining soil |
| Soil pH: | Between 5 and 8 |
| Sunlight Exposure: | Full sun |
| Required Growing Temperature: | 68°F – 86°F (20 – 30°C) |
Creeping thyme is a hardy, low-growing plant. You can plant it between Knock Out roses to control pests and diseases. It grows fast and will soon cover the ground around your rose bushes, serving as a natural pest barrier. It’s perfect for edging a garden bed or border to deter pests such as Japanese beetles, aphids, and other insects attacking the roses.
This plant also doesn’t take up much room in the garden. To keep it healthy, prune the dead flowers often so they don’t spread diseases onto other plants in your garden. Water them after planting until the roots get established, but don’t let it sit in stagnant water.
10. Verbenas
| USDA Hardiness Zone: | 8 – 11 |
| Best Soil Type: | Well-drained soil |
| Soil pH: | Between 5.8 and 7.2 (slightly acidic to neutral) |
| Sunlight Exposure: | Full sun |
| Required Growing Temperature: | 65°F – 75°F (18°C – 24°C) |
Verbena is an annual plant commonly grown as a ground cover. It spreads fast and covers bare spaces in the garden easily. It’s also popular because it attracts butterflies and hummingbirds to the garden with its colorful flowers.
Verbena has a long blooming season. It produces beautiful flowers with long stems that add color to your garden throughout summer. Verbenas and Knock Out roses bloom at the same time.
Usually, verbenas are planted near roses because they conserve the soil’s moisture. The two plants are also heat tolerant. One inch of water per week is enough-don’t make the foliage wet.
Vegetable Companions for Knock Out Roses
11. Parsley
| USDA Hardiness Zone: | 4 – 9 |
| Best Soil Type: | Well-drained soil full of organic matter |
| Soil pH: | 6.0 – 7.0 |
| Sunlight Exposure: | More than six hours of full sunlight per day |
| Required Growing Temperature: | 50°F – 70°F (10°C – 21°C) |
Parsley is an easy-to-grow herb you can use as an edging plant or as part of a ground cover. It’s an excellent companion plant for Knock Out roses. It keeps away rose beetles, aphids, and other pests that prey on young rose buds. It also adds nutrients to the soil.
When planted with Knock Out roses, parsley also improves their smell. You can grow parsley any season, but it’s best to wait until after the last frost date before planting it in your garden. This way, you won’t disturb any dormant roots of your Knock Out roses. The parsley will need just one or two inches of rainwater every week (Water it if there’s no rain)
Allium Companions for Knock Out Roses
12. Garlic, Onions, Leeks, Scallions, Shallots, and Chives
| USDA Hardiness Zone: | 3 – 9 |
| Best Soil Type: | Well-drained soil |
| Soil pH: | 6.0 – 7.0 |
| Sunlight Exposure: | Full sun |
| Required Growing Temperature: | 54 – 75°F (12°C – 24°C) |
Alliums are hardy perennials that grow well in most climates. You can plant them in spring or fall.
Besides, you can plant them with almost any type of rose. They don’t take up much space, so they shouldn’t pose too many problems if you want to plant them near your Knock Out roses.
The alliums’ pungent smell repels Japanese beetles, aphids, and other pests that can damage your Knock Out roses. They also prevent black spot disease from attacking your roses.
The Worst Companion Plants for Knock-Out Roses
- Fuchsias: They need a lot of moisture and shade. It makes them the worst companion plants because Knock Out roses don’t need a lot of shade and moisture to grow well. So, the two cannot grow well together.
- Large Trees and Shrubs: They may shade out your Knock Out roses and prevent them from receiving enough sunlight. Trees and shrubs will also deprive Knock Out roses of nutrients and water.
- Hydrangeas: These beautiful flowers can be an excellent addition to your garden, but they are also one of the worst companion plants for Knock out roses. Their growing conditions differ. Hydrangeas need moist soil and a lot of shade to thrive. Knock Out roses don’t need shade and moist soil.
Conclusion
So, there you have it! A list of ideal companion plants for Knock Out roses. Now, you can make your planting even more interesting and diverse. The next time you have a planting project in your garden, consider companion planting to mitigate disease spread as well as deter pests.
In the end, companion planting will help your roses stay healthier and more vibrant. Happy gardening!
Featured Image Credit: Bethany Anthony, Shutterstock
Contents
