10 Compatibility Nightmares: Why Certain Plants Clash with Dahlias in Your Garden
Unleashing the Spectacular Dahlia: Blooming from Summer to Autumn's Bite
aneous flowers, stunning colors, and long-lasting beauty - these are some of dahlias' most captivating qualities, making them a coveted addition to many gardens. However, establishing dahlias alongside the incorrect companions can sabotage their growth, either through resource-sharing contests, overshadowing, or attracting pests and diseases. To help your dahlias flourish, here's a list of plants you should avoid growing alongside them.
- Grace Lam, the visionary mastermind behind Fivefork Farms, a sprawling 38-acre haven of rolling fields and woodlands brimming with blossoms
- Adrienne Roethling, the experienced head gardener for a prestigious private estate and a former curator at the Plant Delights Nursery’s Juniper Level Botanic Gardens
A Garden Full of Dahlias: Making Sure the Show Goes On
Roses
With their classic charm and intoxicating fragrance, roses are more than worthy of a place in the garden. Yet, growing them alongside dahlias calls for careful attention and nutrient management, as both plants are heavy feeders. Grace Lam of Fivefork Farms cautions that, while it is not impossible to make it work, frequent fertilizing is essential.
Chives
Known for their potent aroma and ease of cultivation, chives serve as deterrents for rabbits and other pests. However, the pests they attract are aphids, which can put dahlias at risk. Adrienne Roethling, the head gardener for the private estate, advises keeping plants with aphid-targeting capabilities far from desired ones, as aphids spread diseases.
Walnuts
Not only do walnut trees grow to an intimidating 90 feet tall, casting too much shade over sun-loving dahlias, but their sizable fruits can also cause damage. Furthermore, most parts of the tree release a harmful chemical that becomes toxic in the air, potentially harming sensitive plants. Even after the tree's removal, the toxin can linger in the soil for years.
Tomatoes
Tomatoes are prone to numerous diseases that can affect the soil, posing a threat to surrounding plants, such as dahlias. According to Roethling, while these ailments typically remain within the same family, they could still infect non-solanaceous plants like dahlias. Infected plant parts should be discarded as they fall to prevent further contamination.
Canna Lilies
Canna lilies, with their eye-catching leaves and vibrant blooms, can make an impressive impact on your garden. However, their large, soft leaves also attract Japanese beetles, which will not hesitate to devour dahlias. Roethling suggests keeping desirable plants at a reasonable distance to minimize the risk.
Summer Squash
The wide, sprawling foliage of summer squash can create issues for dahlias. While the leaves can effectively suppress weeds, they rest close to the ground and are susceptible to powdery mildew. This fungal disease can spread to neighboring plants. Elevating the summer squash foliage using trellis support can help prevent this, but it's best to grow this plant separately from your dahlias to ensure the flowers stay healthy.
Mint
Known for its versatile flavors, mint has become a popular garden staple. However, its aggressive root system means it's best to grow only in containers. Allowing mint to roam freely can deprive dahlias of essential nutrients and reduce their flower production.
Morning Glory
Morning glory flowers are prolific and spread quickly. While this can be a positive trait in the garden, it can jeopardize dahlias by spreading self-seeded seedlings that can overshadow and compete with desirable plants.
Elephant Ears
Known for their large leaves capable of reaching 5 to 6 feet in diameter, elephant ear plants can challenge dahlias for valuable space and resources. Roethling recommends keeping dahlias at a safe distance to avoid root competition.
Lavender
Dahlias require consistently moist soil to thrive, contrasting lavender's drought tolerance. Grace Lam advises steering clear of partnering plants with contrasting water preferences, as dahlias require constant moisture.
By steering clear of the plants mentioned above, you can provide the ideal growing conditions for your dahlias to flourish and display their resplendent blooms.
- Martha Stewart, a well-known lifestyle influencer, may not recommend growing dahlias alongside roses in her home-and-garden projects, considering the nutrient management required for both plants.
- In a flower garden, it's essential to keep chives and mint, which can attract pests like aphids and grow aggressively in the soil, at a distance from dahlias to protect them.
- When planning a garden containing dahlias, one should consider the mature height of walnut trees and keep them far enough away to avoid casting excessive shade and releasing harmful chemicals that may affect the growth of dahlias.
