How to Care for Rosemary Plants, a Drought-Tolerant Herb You Can Grow Indoors and Outside

Rosemary is a great addition to any garden because of its culinary and pest-repelling purposes. In cooking, rosemary adds flavor and character to some of your favorite dishes. It also has a potent fragrance that repels common garden pests, like Japanese beetles, carrot flies, slugs, and snails. What's more, rosemary is a hardy, drought-tolerant plant that can thrive in a variety of growing conditions. Add this fragrant herb to your backyard garden or windowsill container collection to elevate your plantings—and the quality of your recipes. We spoke to experts to help guide you along, from selecting the right variety to planting, harvesting, and storing.

Types of Rosemary

When choosing a type of rosemary to add to your garden, the options can seem endless, but not all plants are created equal. "Rosemary is quite sturdy and will grow in many places, but it won't always taste the same way," says Evangelia Koutsovoulou of Greek spice and herb company Daphnis and Chloe. "For a higher rate of success, you should pick a local variety or at least one that prospers in climates similar to yours."

Since some rosemary varieties can grow up to 6 feet tall and wide, you should know how much space you have for the plant before choosing one, says Jessica Mercer of Plant Addicts. Some rosemary plants are better suited for container gardens; others can be grown as privacy hedges.

• Arp rosemary: Developed by the National Arboretum, this is the hardiest type of rosemary available. "This selection reaches about 3 feet high and wide and has an upright, mounded form. The dark greenish-gray foliage has an herbal fragrance and is prized for culinary uses," says Mercer.
• Salem rosemary: This compact variety can be a good option for smaller spaces. "Salem Rosemary is an upright variety that reaches about 3 feet high and 2 feet wide," says Mercer. "Unlike other varieties, it has a high tolerance for humidity, along with excellent winter hardiness down to zone 7. It develops pretty blue flowers in spring among its highly fragrant, silver-green foliage."
• Chef's Choice rosemary: Another smaller variety is Chef's Choice, which grows to about 1 foot high. "This selection is perfect for culinary use because the aromatic oil content is higher than in other varieties," says Mercer. The fine, evergreen foliage is highly fragrant and has a spicy flavor."
• Prostrate rosemary: With a low spreading habit, this variety works well for cascading over a stone wall or a container. "It also grows well as a groundcover and will cover an area about 3 feet wide. The dense, fragrant foliage can be used in cooking or medicinal applications," says Mercer.

How to Plant Rosemary

When planting rosemary, choose a spot with the right light exposure and well-draining soil. You can plant rosemary in the ground either from container or by seed.

From Container

Planting rosemary from a container is the easiest method. If you're planting multiple rosemary plants, space them about 2 to 3 feet apart. "Ample air circulation is crucial for preventing fungal diseases and giving each plant enough room to grow," says Carrie Spoonemore, co-creator of Park Seed's From Seed to Spoon app.

1. Dig a hole the same size as the root ball.
2. Place the plant in the ground so the top of the root ball is level with the soil.
3. Backfill the hole.
4. Water the new plant well, saturating the root ball.
5. Check the soil for at least two weeks, watering the plant as the top inch of soil dries.

From Seed

Growing rosemary from seed can be time- and labor-intensive. "Rosemary is notoriously difficult to grow from seed," says Mercer. For best chances, start rosemary seeds indoors three months before the last expected frost date.

1. Use a container or seed tray with drainage holes and fill the compartments with sterilized seed starting mix.
2. Place seeds in the container and cover lightly with the starting mix, as rosemary seeds require light to germinate.
3. Place the container or tray in a warm location, with temperatures between 65 to 70 degrees Fahrenheit, or use a heating mat. Provide 10 to 12 hours of full-spectrum light per day.
4. Keep the seed medium consistently moist, preferably by bottom watering to prevent damping off.
5. Cover the container with plastic wrap or a humidity dome to retain moisture.
6. The seeds take 14 to 21 days to sprout. Once the seeds sprout, remove the cover and position the light source so it is a few inches above the seedlings.
7. Harden off the seedlings before transplanting outdoors.

How to Care for Rosemary

All types of rosemary succeed with similar care, says Mercer. Once you've selected the right type, find a sunny space that offers your plants enough room to grow up and out.

Light

Plant rosemary in full-sun locations where the plant can benefit from at least six hours of daily direct sunlight.

Water

Rosemary is drought-tolerant, so it can stand up to dry soil. "Rosemary likes dry conditions," says Spoonemore. "Water when the top inch of soil feels dry, but be careful not to overwater."

Soil

When it comes to soil, rosemary requires excellent drainage. "The soil must drain well because rosemary is susceptible to root rot in clay or boggy soils," says Mercer. "Poorly draining soil should be amended with copious amounts of grit or pumice prior to planting rosemary." Raised beds can also allow for better drainage in areas with heavy, wet soil.

Fertilizer

Rosemary can thrive with a springtime application of compost in place of mulch, says Mercer; it doesn't require fertilizer. However, if you do opt for fertilizer, choose a well-balanced product that "doesn't promote excessive growth," says Spoonemore: "Over-fertilizing can actually harm the plant's growth and reduce the potency of its oils, flavor, and aroma."

How to Grow Rosemary in a Container

Rosemary grows well in a container, making it a good choice for indoor gardens or a pot placed in the sunniest part of your patio. The same sun, soil, and watering requirements apply. If growing indoors, place rosemary in an area where it will get bright, south-facing exposure with six hours of direct sunlight per day. "Avoid using a container that is much bigger than the plant because a large soil volume will retain too much moisture, potentially damaging the roots over time," says Mercer. Make sure the container has a drainage hole, as rosemary doesn't like to be waterlogged.

Once you've chosen your pot, fill it with well-draining soil, like a succulent mix or a gritty potting soil with plenty of perlite, pumice, or grit mixed in for drainage. For best results, choose a full-sun location where your rosemary can be protected from strong winds.

How to Prune Rosemary

Keep your rosemary full and bushy with regular pruning and harvesting. But be careful to never prune the bush to more than one-third of its size. "Cut back branches to a main stem to avoid leaving unsightly stumps," says Mercer. "Avoid cutting back into old, woody growth, which will not re-sprout after hard pruning."

How to Propagate Rosemary

Spread the benefits of a thriving rosemary plant by sharing stem cuttings with your neighbors, friends, and family members. "The best time to propagate is in the spring or early summer when the plant is actively growing," says Spoonemore. "Select a healthy stem and remove the bottom few inches of leaves. Dip the cut end in rooting hormone and plant in a well-draining soil. Keep the soil consistently moist and in a warm location."

How to Transplant Rosemary

Transplant rosemary sparingly, as the plant is finicky and prefers its roots to remain untouched. "If transplanting is necessary, move rosemary in early spring or at least two weeks before the first frost in the fall," says Mercer.

Loosen the soil around the base of the plant with a spade or a fork, and dig down to try to extract as much of the root ball as possible. "A mature rosemary plant can have an extensive root system, approximately the size of the top growth. Water the new transplant well to help the roots settle into the new site," says Mercer.

How to Overwinter Rosemary

Rosemary is hardy in zones 7 and higher but doesn't always survive the winter in cooler areas. "Its main weakness is susceptibility to cold damage," says Mercer. "In those areas, it would need to be overwintered indoors."

Protect rosemary from winter temperatures by applying a thick layer of mulch around the base of the plant. "Do not let the mulch touch the trunk of the plant and invite fungal infection," says Mercer. "Move potted plants to a protected area, such as a covered porch or patio; exposure to too much moisture during the winter can kill rosemary plants."

When to Harvest Rosemary

Regular harvesting keeps your rosemary plant healthy—and allows you to reap the herb's culinary benefits. The ideal time to harvest rosemary is spring or summer, and in the morning when the plant's essential oils are at their peak. "We choose to harvest when [the plants] start blossoming because that's when the leaves are at their peak," says Koutsovoulou. If you're cultivating for home use, it makes sense to harvest as needed.

How to Store Rosemary

When storing fresh rosemary, keeping it damp is key. Place fresh herbs in a glass with water, much like you would for fresh cut flowers. Put a produce bag on top of the herb, wrapping it over the glass so it's covered, and tying it off to act as its own greenhouse.

How to Dry Rosemary

Dry rosemary in a well-aired room free of humidity. "Lay the branches in the shade for a few days. A large table or shelve should do," says Koutsovoulou. "You want them to dry fast because otherwise the quality might get deteriorated." You'll know your rosemary is ready to store in jars once it's crumbly and completely dry.

Common Problems With Rosemary

Rosemary is a relatively tough plant, but it is susceptible to root rot from overwatering or from too-heavy soil. If the leaves start to turn yellow or if growth slows down, try scaling back your watering schedule. Common pests, like aphids, mealybugs, or spider mites, can also take up residence in the plant, but these can be easily treated with insecticidal soap.