Rosemary is a tender perennial shrub that grows from two to six feet tall, depending on the variety and growing conditions. This lovely herb is a favorite to grow in the culinary herb garden.
It has woody stems with pointed needle-like leaves. The leaves are shiny dark green on top and a softer muted shade underneath. Flowers bloom in shades of blue, purple and sometimes pink in the early spring.
Rosemary is often called the herb of remembrance for it’s healing properties and ability to increase the memory. It can be found growing wild near the sea in the Mediterranean which is why some refer to it as the “Dew of the Sea.”
This herb is a favorite for savory dishes and has an earthy pine-like scent with hints of mint and eucalyptus. Used in the kitchen for flavoring meats, it also pairs well with chicken, vegetables, stews. Blending nicely with garlic and wine, rosemary can be used to enhance the flavor of bread, potatoes and other starchy dishes.
Growing Rosemary in the Garden
Grow rosemary in full sun and loamy garden soil, but somewhat drier conditions. Rosemary can grow in slightly acidic soil but prefers it to be on the alkaline side which will result in a richer flavor profile and more compact plant growth.
Good drainage is a must since this herb does not like to sit in water. When mulching, allow some space around the base of the plant to avoid retaining too much water against the stems which can lead to fungal growth or root rot. A drier mulch, rocks or even sand work best.
Rosemary is a tender perennial, so while it will grow year after year, it may not survive in very harsh winters. In zone 7 or warmer, Rosemary can be grown outside all year long.
In zone 6 or lower, it can be grown in a large pot & overwintered indoors in other sheltered location such as a greenhouse in colder regions.
Companion Planting with Rosemary
Good companions for rosemary in the vegetable garden include broccoli, cabbage, and cauliflower since they can ward off the cabbage butterfly, beetles, and flies. But keep them away from potatoes and pumpkins.
In the herb garden, plant rosemary near thyme, marjoram, and oregano since they have similar growing requirements. Sage also does very well when planted with rosemary. If you are planting in a container, give each enough room so the rosemary doesn’t block the sunlight from your shorter herbs.
When to Plant Rosemary
Growing From Seed
If you are growing from seed, start your seeds indoors about 8-10 weeks before the last frost. Use a seed starting kit and plant your seeds 1/4 inch deep. Your seeds will sprout in about 2-3 weeks. Remove the cover and follow our guide on growing herbs from seed for best results.
Planting Seedlings in the Garden
For young plants, being planting in early spring after the last frost date in your area. Dig a hole about twice as wide and deep as the container. Select a location with the mature size of the plant in mind as most common rosemary varieties can grow between 2 to 4 feet wide.
Maintaining Your Rosemary Plant
Lightly prune your rosemary plants to keep their busy shape. After flowering has finished in the spring is a good time to prune your Rosemary plant. This will encourage new growth Pruning also keeps good air circulation around your plant and can ward off fungus or disease.
Water throughout the season about every one to two weeks, more when there is a lack of rain. Let the soil dry out slightly between waterings. Feed your plant with a liquid fertilizer about once a month when growing in containers.
If you are growing rosemary in a cooler location and you won’t be able to bring it inside, take cuttings toward the end of the season so you can start new plants indoors over the winter months. If you have a larger plant, you can also divide it to fit in smaller containers.
Common Problems When Growing Rosemary
Rosemary is a pretty easy herb to grow, however, there are a few problems you may run into.
- Root Rot. Root rot occurs mostly in potted rosemary plants due to overwatering. Be sure to let the soil dry out between watering. Clay pots are also recommended since they help the soil to drain properly. If you aren’t using clay pots, be sure to select one with drainage holes.
- Powdery Mildew can also affect this herb.
- Pests. Pests such as spider mites, mealybugs or whiteflies can be a problem, especially when overwintering rosemary since the plant is likely to experience a little adjustment period from the outdoors.
Popular Varieties of Rosemary
- Rosmarinus officinalis is the most commonly found rosemary which has an upright bushy habit and can grow to 5 five tall. Tuscan Blue is a popular choice and one of the tallest Rosemary plants with large leaves and pretty blue flowers.
- Prostate Rosemary is the trailing form that is better suited to the front of the garden bed. It can spread from four to eight feet wide.
Propagation: Starting New Plants
New plants are often purchased from garden centers or created from cuttings or division. Rosemary can be started from seed, but it may take a full year to produce enough stems for a good harvest. Germination rates are also notoriously poor, so start a much larger number of seeds than you need.
Where to Buy Rosemary Plants and Seeds
The common varieties of rosemary can be found in most garden centers in 3 or 4-inch pots. Many popular online brands are now selling on Amazon or Etsy. Here are just a few of them.
Many smaller garden shops also sell herb plants on Etsy. For example, this beautiful Rosemary plant is available from Hirts Gardens.
If you want to give growing from seed a try, Botanical Interests carries Heirloom Rosemary Seeds.
You can buy rosemary seeds or plants from Burpee directly on their website or use the Amazon platform.
Trim newer stems from the main plant. Hold the tip, then strip the leaves from the stem before chopping. The stems are not eaten but can be used as skewers on the grill. This will impart a nice flavor during cooking.
Here’s a great video that demonstrates the proper way to harvest rosemary stems from your plant.
Preserving Rosemary: How Long Does it Last?
The method you choose for preserving rosemary depends on the length of time you need to keep it. Here is a general guide to help you choose the correct method.
- 3-5 days: Cut stems can be kept in damp paper towels and stored in a refrigerated airtight container.
- Up to a month: Cut the stems of fresh rosemary & place in a glass of water similar to cut flowers. Place on a windowsill that receives indirect light. If the stems sprout roots, they will stay fresh longer or can be grown on like cuttings to create new plants.
- 3-6 months: Full sprigs can also be frozen, then thawed & used similarly as fresh.
- Up to a year: Rosemary can be dried and will hold it’s flavor well. Hang in small bundles to dry for about 2 weeks. Cover the bundles with paper bags to keep out dust. Dried rosemary leaves are very tough, so they may not fully soften when cooking. Either chop very finely or use bundled in cheesecloth, then remove before serving.
Cooking with Rosemary
Finely chop rosemary leaves for addition to most recipes. Rosemary can also be used in bundles with other herbs, then removed at the end of the cooking cycle.
Rosemary has a strong flavor so use sparingly so it doesn’t overpower the dish. Rosemary is a great herb to use when roasting vegetables or adding flavor to vinegar & oils.
Frequently Asked Questions
Plant rosemary in the spring garden after the soil has warmed.
Grow rosemary in full sun and well-draining soil. Rosemary can grow up to 5 feet tall so be sure to allow enough room in the garden for it to thrive.
When planted from seed, rosemary will sprout in 2-3 weeks.
Rosemary is a tender perennial that can grow outdoors in zone 7 or warmer. In cooler areas, it can be treated as an annual or be overwintered indoors.