Companion planting can be defined as the close planting of different species based on their ability to enhance one another's growth or offer some form of pest protection or other advantages. Sometimes this is a matter of choosing plants with different growth habits that don't compete with one another or those that have different nutrient needs that make efficient use of soil. Or, there may be plants that offer the ability to repel pest invaders, attract beneficial insects, or make the plants less susceptible to diseases.
Strategic companion planting is especially important in small gardens or wherever careful space planning is needed.
The best companion plants for roses are those that share the same care requirements (in terms of light, moisture, and fertility) and also help the roses grow better. Here are the most common rose companion plants.
Members of the Allium Family
All members of the onion family are useful companions for roses. They deter aphids and other pests by confusing them with their strong scent. They also help roses combat black spot. While garlic and chives are most commonly recommended, ornamental alliums can also be used, and you get the bonus of beautiful flowers in addition to pest and disease deterrence.
Herbal Companions for Roses
Much like alliums, certain herbs help roses deter pests (most notably, aphids). The herbs below are the ones that work best with roses.
There are several varieties of scented geranium, and they seem to all work equally well as companion plants for roses.
- Scented Geraniums
Flower Companions That Deter Pests
Many flowers make attractive additions to a rose garden, and, if they have the same light, moisture, and fertility requirements, they can be planted quite successfully near roses.
The flowering plants listed below, however, also provide protection against pests and diseases.
- Lavender - helps deter rabbits.
- Yarrow - attracts ladybugs, which will then eat any nearby aphids.
- Marigolds - deter pests and help encourage strong plant growth.
- Geraniums – repel Japanese beetles, aphids, and other rose beetles
Plants to Grow Beneath Roses
Because roses generally are upright plants that are sparse near the bottom, a variety of ground-hugging flowers will work nicely when planted around the base of rose bushes to cover bare ground. Here are some good choices.
Perennials: Anise, hyssop, Bellflower, catmint, baptisia, garden phlox, lady’s mantle, lavender, lilies, Russian sage, spurge, wormwood, yarrow.
Annuals: Annual phlox, alyssum, heliotrope, larkspur, million bells, pansies, flowering tobacco.
Plants to Avoid Near Roses
In general, you want to avoid companion plants that provide too much shade, as roses require a lot of sun and will react badly if neighboring plants cast a shadow over them. And also avoid plants with roots that spread too far and might encroach on the root systems of your roses. And finally, avoid any plants that are known to be invasive―prone to uncontrollable spreading.