9 Amazing Aster Companion Plants & 5 to Avoid

Good Companion Plants for Asters

Nasturtium

Nasturtiums are not only colorful but also a fantastic companion for asters. They deter pests that commonly affect asters, such as aphids, with their strong scent. Plus, nasturtiums are edible, adding a peppery flavor to salads. Planting them together enhances biodiversity and pest control.

• Planting Guide:
  1. Choose a sunny spot with well-draining soil.
  2. Plant nasturtium seeds directly in the ground, about 1/2 inch deep.
  3. Space the seeds 10 to 12 inches apart.
  4. Water regularly, but avoid overwatering.
  5. Nasturtiums will bloom in about 35 to 52 days, complementing your asters.

Curious about other nasturtium companions? Explore more in our detailed post here.

Marigold

Marigolds are not just pretty; they’re powerful. Their roots secrete a substance that repels nematodes, protecting asters from these underground pests. The bright blooms of marigolds also attract beneficial insects, aiding in pollination.

• How to Pair with Asters:
  1. Select a location that receives full sun to partial shade.
  2. Sow marigold seeds or transplant seedlings near your asters.
  3. Ensure the soil is fertile and well-drained.
  4. Space marigolds about 8 inches apart for optimal growth.
  5. Keep the soil moist, especially during hot, dry periods.

Discover more about marigold companions in our comprehensive article here.

Lavender

Lavender, with its soothing fragrance, is another excellent partner for asters. It helps deter deer and rabbits, which might be tempted by aster blooms. Lavender’s drought tolerance also complements the moisture needs of asters, making them a low-maintenance pairing.

• Planting Lavender and Asters Together:
  1. Choose a sunny spot with well-draining, slightly alkaline soil.
  2. Plant lavender bushes about 18 to 24 inches apart from asters.
  3. Water the lavender sparingly, as it prefers drier conditions.
  4. Mulch around the plants to retain moisture and suppress weeds.

For more insights on lavender companion planting, check out our article here.

Calendula

Calendulas offer more than their cheerful blooms; they’re a gardener’s ally against pests. Acting as a trap for aphids, they keep these pests away from asters. Calendulas also promote soil health, enriching the garden ecosystem.

• How to Grow Calendulas with Asters:
  1. Find a spot with full sun or partial shade.
  2. Sow calendula seeds in early spring, barely covering them with soil.
  3. Space the plants 12 to 18 inches apart.
  4. Water regularly, ensuring the soil stays moist but not waterlogged.
  5. Deadhead spent blooms to encourage continuous flowering.

Learn about calendula’s companions in our detailed guide here.

Chives

Chives bring more than culinary delight; they’re beneficial for asters. Their oniony scent deters pests and diseases, and their purple flowers attract pollinators. Chives can help improve the growth and health of asters.

• Combining Chives and Asters:
  1. Choose a sunny location with fertile, well-drained soil.
  2. Plant chive seedlings or sow seeds near your asters.
  3. Keep the soil consistently moist, especially during dry spells.
  4. Cut back chives to 2 inches above the ground after flowering to encourage new growth.

Interested in chive companion plants? Dive deeper in our article here.

Basil

Basil is not only a kitchen staple but also a great companion for asters. It repels thrips, mosquitoes, and flies, creating a healthier environment for asters to flourish. Basil’s strong scent is the key to its pest-repelling properties.

• Planting Basil with Asters:
  1. Select a location with full sun and rich, well-draining soil.
  2. Plant basil seedlings or seeds close to your asters, spacing them about 12 inches apart.
  3. Water basil regularly, keeping the soil evenly moist.
  4. Harvest basil leaves frequently to encourage bushier growth.

For a deeper understanding of basil companion plants, visit our post here.

Bee Balm

Bee balm is a striking plant that not only adds beauty to your garden but also serves as an excellent companion for asters. It attracts bees and butterflies, enhancing pollination for a more vibrant garden. The aromatic leaves of bee balm can also help deter certain pests.

• How to Grow Bee Balm with Asters:
  1. Pick a spot in your garden that gets full sun to partial shade.
  2. Plant bee balm and asters at least 18 inches apart to allow room for growth.
  3. Water regularly, as bee balm prefers moist soil.
  4. Deadhead spent flowers to promote more blooms.

For more information on bee balm companions, check our detailed guide here.

Yarrow

Yarrow is another fantastic companion for asters, thanks to its ability to attract beneficial insects and improve soil quality. Its deep roots can bring up nutrients for shallower-rooting plants like asters, and its flowers attract predatory insects that help control pests.

• Planting Yarrow with Asters:
  1. Choose an area with full sun and well-drained soil.
  2. Plant yarrow and asters about 12 to 24 inches apart.
  3. Water yarrow moderately; it’s drought-tolerant once established.
  4. Cut back yarrow after flowering to encourage a second bloom.

Explore more about yarrow companion planting in our article here.

Zinnia

Zinnias bring a pop of color to any garden and are beneficial companions for asters. They attract a wide variety of pollinators, which helps increase the bloom production of both plants. Zinnias also help deter cucumber beetles and tomato worms.

• Growing Zinnias with Asters:
  1. Find a sunny location as both plants love the sun.
  2. Space zinnias and asters about 12 inches apart to ensure good air circulation.
  3. Keep the soil moist, especially during dry periods.
  4. Deadhead zinnias to encourage more blooms and extend flowering time.

To learn more about zinnia companion plants, visit our comprehensive guide here.

Plants to Avoid Planting with Asters

Mint

While mint is a wonderful herb, it’s not the best neighbor for asters. Mint’s aggressive growth can quickly overrun asters and other nearby plants. Its invasive nature requires careful management to prevent it from taking over the garden.

Fennel

Fennel is known to be allelopathic, meaning it releases substances that can inhibit the growth of surrounding plants, including asters. It’s best to keep fennel isolated from your aster beds to ensure your asters can thrive.

Cabbage

Cabbage and other brassicas can attract pests that also enjoy feasting on asters. Planting them together can inadvertently create a buffet for pests, leading to more damage to both plants.

Walnut Trees

Walnut trees produce juglone, a compound harmful to many garden plants, including asters. The roots, leaves, and nuts of walnut trees can release juglone into the soil, inhibiting the growth of asters.

Oregano

While oregano is generally a good companion for many plants, its strong scent can overpower the more subtle fragrances of aster flowers. Additionally, oregano can spread quite aggressively, potentially competing with asters for space and nutrients.

Companion Planting Chart for Asters

Here’s a quick reference guide to the best companion plants for asters and those to avoid:

Good Companions	Why They’re Good
Nasturtium	Deters aphids; adds color and variety.
Marigold	Repels nematodes; attracts beneficial insects.
Lavender	Deters deer and rabbits; requires similar care.
Calendula	Acts as a trap for pests; enriches soil health.
Chives	Repels pests and diseases; attracts pollinators.
Basil	Repels thrips, mosquitoes, and flies.
Bee Balm	Attracts bees and butterflies; deters pests.
Yarrow	Attracts beneficial insects; improves soil quality.
Zinnia	Attracts pollinators; deters certain pests.