Can You Plant Basil and Rosemary Together?
Basil and rosemary bring the fresh, herby flavor of summer. They also add a wonderful aroma to the garden and carry beneficial qualities for surrounding plants. But while they pair together in the kitchen, they aren’t a set match in the landscape. Gardening expert Katherine Rowe explores growing the duo together and their better pairings.
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Rosemary and basil make a delicious pairing in Herbes de Provence with bright, savory flavors that encapsulate the taste of summer. But do they make good garden neighbors? Not necessarily. While a few primary growing requirements overlap, others aren’t the same. There are better companions for both, whether in the garden or a container.
Rosemary and basil can certainly thrive in the same area, but spacing them to account for different preferences and growth habits is wise. Following the science behind companion planting, growing rosemary with basil doesn’t have obvious advantages for either. Enjoy them together in culinary endeavors, but give them some space in the garden to meet the needs of both.
Planting Basil With Rosemary
Basil and rosemary share some of the same growing preferences. Both thrive in the heat and rely on full sun (six or more hours of sunlight daily) for the best vigor. Basil can tolerate partial shade, but rosemary, from the sun-drenched Mediterranean, relishes more direct exposure. With tender leaves, basil may scorch in intense afternoon rays. Offer a bit of afternoon shade protection in hot, southern climates.
Both herbs also need well-draining soils to flourish. Ample airflow, too, helps prevent fungal problems that arise from overcrowding. Basil is susceptible to downy mildew, rosemary to powdery mildew, and both to botrytis (gray mold) in damp, humid conditions. Root rot happens in both waterlogged and saturated soils.
The Primary Cultural Differences
The main area where basil and rosemary differ in their growing conditions relates to water and soil moisture. Basil needs regular water throughout the growing season for evenly moist soils. Rosemary prefers dry situations and needs little, if any, supplemental irrigation.
Rosemary is drought-tolerant and accustomed to hot, arid summers and cool, wet winters. Basil, likely native to Southeast Asia and subtropical Africa, needs more water for its annual growth.
Another growing requirement difference is soil fertility. Neither rosemary nor basil are heavy feeders, but basil benefits from organically rich soils. A boost from fertilizer at planting and again about two months later helps support growth during the summer. Rosemary, though, tolerates leaner, sandier textures. While it tolerates compost and some organic richness, it doesn’t benefit from supplemental fertilizer.
Form and Habit
Outside of zone 10, Ocimum basilicum (basil) grows as an annual. It also grows indoors year-round or to overwinter, but eventually it fades. Starting fresh in spring brings tender new growth. Salvia rosmarinus (rosemary) perennializes in zones 8-11. Hardier varieties (‘Arp’ and ‘Madelene Hill’) are cold–hardy to zone 6 with protection. Rosemary is challenging to grow indoors without pest problems like spider mites.
Rosemary, whether an upright or spreading variety, can form a small shrub. Stiff, woody stems and extensive roots take up greater space at maturity than basil. Basil has dense, bushy leaves but typically stays lower and smaller than rosemary. The annual grows quickly in a single season.
In close proximity, it’s possible that rosemary can crowd basil. It may overshadow the smaller form and compete for resources like sunlight, moisture, and nutrients.
In the Ground
To grow the duo in the same vegetable plot, leave a little space between them to attain ideal soil conditions. Plant rosemary and basil two or three rows apart to distinguish growing requirements.
Irrigate the basil and like crops, but skip the rosemary. Same for fertilizer; no need to use the resources on the easy-going Mediterranean native.
In Raised Beds and Pots
Grow rosemary in its own pot, or combine it with other drought-tolerant, sun-loving herbs like lavender and thyme. Ensure a large enough container to accommodate mature growth or for a combination planting. You’ll also need to water less frequently with larger pots and the drought-tolerant selections (but don’t allow soils to dry completely).
Basil pairs with other selections that need water more often than rosemary, including edible flowers like calendula. Both rosemary and basil bridge the ornamental and edible landscape and make unique additions to borders and decorative pots.
In raised beds, place rosemary on an end cap or an area that can be separate from irrigation and fertilizer. The north end of the bed keeps it from shading lower-growing crops. At the south end, it can protect smaller selections from sunscald.
Companion Planting
Companion planting is arranging plants in close proximity to benefit one or both. It’s a space-efficient measure, and it reduces pest damage by partnering with natural deterrents. Certain substances and essential oils have repellent qualities to deflect pests from others. They help ward off pests through scent, masking, or attracting beneficial predators to the area.
Other companion planting techniques include varying growing seasons and harvest times. With overlapping growth, one crop may produce and fade just as the other begins to develop. Radishes and carrots make prime companions, as the fast-developing radishes are ready for plucking as the carrots continue to develop. Their harvest aerates the soil for the developing root vegetables.
Other pairings provide cooling shade to smaller specimens. Tall tomatoes shield a late lettuce crop from increasing heat, for example. Those with different root structures benefit soil health without competition. Pairing different mineral needs, too, reduces competition for nutrients. Bush beans and eggplants, for example, extract different nutrients and grow harmoniously.
Good partners may even improve flavor. With their natural substances in roots, leaves, and stems, they can enhance their paired crops.
What to Plant Instead
Rosemary and basil make good companions to other crops. With their aromatic foliage and essential oils, they help repel pests. Their oils also deter mosquitoes; use them around seating areas to enjoy their aromatherapy while lessening the biting insects.
Rosemary Companions
Rosemary is ideal with other Mediterranean herbs like sage, lavender, and thyme, which tolerate dry conditions and full sun.
Other companions include:
- Broccoli
- Cabbage
- Carrots
- Marigolds
- Onions
- Strawberries
Rosemary is an excellent strawberry companion, noted to enhance their sweet flavor. The needle-like herb may help deter slugs from the fruits. With strawberries’ low, spreading habit, there’s no competition in upper growth or root space.
With carrots, rosemary helps deter carrot rust flies. Since carrots rely on more water than rosemary, plant them nearby in a less irrigated spot or in a pot.
For Brassicas like cabbage and broccoli, rosemary acts as a masking fragrance. The leafy greens attract cabbage moths and other caterpillars. Rosemary’s high scent screens the Brassica scent to throw the larvae off the host’s scent.
Basil Companions
Basil can be an indicator plant that signals problems in cultural conditions. With its susceptibility to wilt, mildews, and botrytis, it may show signs before other selections. Keep an eye on basil as a lookout for bed or container health.
Pair basil with crops that enjoy the same moisture level and sun exposure.
Partners include:
- Asparagus
- Chamomile
- Chives
- Garlic
- Lettuce
- Oregano
- Parsley
- Tomatoes
Basil and tomatoes are a classic pairing, not only in Caprese salads and pastas but in the garden. Basil may even promote tomato growth. Pair the duo with African marigolds, and you’ll likely see a reduction in thrips.
