Rose Companion Planting — Using Partner Plants for Pest & Disease Control

Companion planting is a cultivation method that involves planting different plants close together to achieve synergistic effects such as pest repellence, disease prevention, and promotion of pollination. By utilizing companion plants in rose cultivation, you can reduce pesticide use while growing healthy roses.

Basic Concept of Companion Planting

Rose companion planting has three main objectives.

Pest Repellence Certain plants emit fragrances and chemical substances that repel pests that attack roses. Herbs in particular are known for their strong scents and high pest-repellent effectiveness.

Attracting Beneficial Insects Planting flowering plants around roses helps attract beneficial insects (natural enemies of pests) such as ladybugs, hoverflies, and parasitic wasps. These beneficial insects prey on pests like aphids.

Soil Improvement Legumes engage in symbiosis with nitrogen-fixing bacteria to enrich the soil. Ground cover plants prevent soil drying and suppress weed growth.

Companion Plants Effective for Pest Repellence

Lavender The strong fragrance of lavender repels aphids and whiteflies. When planted at the base of roses, it creates a beautiful appearance with lavender's purple flowers harmonizing with rose blooms. Since lavender prefers dry conditions, be mindful of the different water requirements when watering.

Rosemary Evergreen rosemary can be used as ground cover to cover the base of roses, and its strong fragrance repels many pests. As it remains green through winter, it adds color to the garden during the season when roses have lost their leaves.

Chives (Allium schoenoprasum) A member of the onion family, chives are said to prevent rose black spot disease. Sulfur compounds released from the underground stems suppress disease-causing pathogens in the soil. They produce small purple round flowers in spring, decorating the base of roses. It is also a practical plant that can be used for culinary purposes.

Garlic Like chives, garlic in the onion genus is believed to be effective in preventing rose diseases. The practice of planting garlic among rose bushes has long been used in Europe. The strong aroma of garlic is said to repel aphids and suppress the occurrence of black spot disease.

Marigold Substances secreted from marigold roots suppress nematodes (roundworms). Additionally, the flowers attract hoverflies, which are natural enemies of aphids. Orange and yellow flowers brighten the base of roses and add color to the garden.

Chamomile Chamomile is sometimes called "the plant's doctor" and is said to have the effect of promoting the health of nearby plants. When planted at the base of roses, it is believed to promote rose health and increase disease resistance. The flowers can also be enjoyed as herbal tea.

Companion Plants That Attract Beneficial Insects

Fennel Hoverflies and parasitic wasps gather on fennel flowers. These beneficial insects are natural enemies of aphids and caterpillars. However, since fennel grows large, plant it where it won't block sunlight to roses.

Yarrow (Achillea millefolium) Yarrow, with small flowers densely clustered, attracts beneficial insects such as ladybugs and green lacewings. Planting it behind roses creates height variation and is also effective from a garden design perspective.

Alyssum Low-spreading alyssum covers the base of roses as ground cover while attracting beneficial insects with its small flowers. The appearance of white or purple flowers covering the ground is beautiful and helps prevent soil drying.

Plants Useful for Soil Improvement

Clover (Trifolium repens) Clover, a legume, engages in symbiosis with nitrogen-fixing bacteria to fix atmospheric nitrogen and supply nutrients to the soil. It spreads as ground cover at the base of roses, prevents soil drying, and suppresses weed growth. The flowers attract bees and enrich the garden's ecosystem.

Comfrey Comfrey's deep roots absorb nutrients from deep underground. When cut leaves are laid around the base of roses, they become excellent mulching material and organic fertilizer. Rich in potassium, it is said to brighten rose flower color.

Planting Methods and Placement Considerations

Key points for effectively positioning companion plants:

• Plant at least 30cm away from the rose base: Planting too close creates competition with rose roots for water and nutrients
• Do not obstruct sunlight to roses: Manage companion plants so they do not grow taller than roses
• Choose plants with similar water requirements: Avoid mixing plants that prefer dryness with those preferring moisture
• Position plants so they don't interfere with rose care (pruning, training, pesticide application)
• Plant invasive plants in pots: Plants that spread via underground stems like mint should be planted in containers to prevent them from taking over the garden

Plants with Poor Compatibility with Roses

Not all plants are suitable as rose companions. Some plants may have negative effects when planted near roses.

• Walnut: Secretes juglone, a substance that inhibits the growth of many plants
• Ivy: Winds around roses and blocks sunlight and air circulation
• Large trees with strong roots: Root competition deprives roses of nutrients and water

Consulting About Roses and Companion Plants at Briqoku

At Briqoku, you can purchase rose seedlings while getting advice on companion planting from rose specialist breeders. Try consulting with breeders about combinations suited to your garden environment and challenge yourself to grow roses without relying excessively on pesticides.