Rosemary (Salvia rosmarinus) leaves are tea-scented, spicy and slightly bitter. They are often used in cooking and can also be used to make herbal tea. Rosemary is an evergreen shrub, and it is currently recognized as the most antioxidant plant. The antioxidant components in rosemary are mainly carnosic acid, carnosol, rosmarinol, ursolic acid, rosmarinic acid and other ingredients.
Rosemary (Salvia rosmarinus) is also often placed indoors to purify the air. Rosemary is native to the Mediterranean coast. It is an evergreen shrub. In summer, it blooms with small blue flowers that look like small water droplets. Therefore, rosmarinus means "dew in the sea" in Latin. Rosemary also symbolizes loyalty, so in European weddings, it is also common for brides to use lost incense as an accessory to tell the world her unswerving love for love.
How to Choose and Prepare a Planting Site
Plant in full sun. The planting site should have well-draining soil.Rosemary (Salvia rosmarinus) won’t tolerate being consistently wet. Be sure to give your plants enough room to grow. Once established, rosemary can eventually grow to about 4 feet tall and spread about 4 feet as well. In the garden, plant near beans, cabbage, carrots, and sage.
When to Grow Rosemary
Rosemary (Salvia rosmarinus) can be grown from seed, but germination rates are generally quite low and seedlings are slow to grow. Therefore, it's strongly recommended to start new rosemary plants from cuttings taken from established plants. Cuttings grow quickly in good conditions and should be ready for outdoor planting in about 8 weeks.
For a head start, plant the seeds or cuttings indoors 8 to 10 weeks before the last spring frost. (See your local frost dates.)
Note: Seeds can take a long time to germinate (2 to 3 weeks), so don't give up right away!
How to Grow Rosemary (Salvia rosmarinus)
Steps for Rosemary (Salvia rosmarinus)Propagation with Cuttings
You will make things far easier on yourself if you start with a nursery-grown plant. Rosemary (Salvia rosmarinus) can take years to fill in, so expect to pay more for a mature plant than for a small rosemary start.
If you would like to start your own rosemary plant, the best option is to start with a cutting. Rosemary seed can be difficult to germinate and often do not grow true to their parent. It's much faster to start with a cutting, and you will be sure of what type of plant you will get.
Snip a 2-inch cutting from the soft, new growth of an established plant.
Remove the leaves from the bottom inch, then dip the cut tip into a rooting hormone and place the dipped end into a container of dampened, sterile seed starting mix that drains well.
Place the container in a warm spot with indirect sunlight. Mist the cuttings daily and make sure the soil does not dry out.
In about 2 to 3 weeks, test for root growth by very gently tugging on the cuttings. Once the cuttings have roots, transplant them into individual pots about 3 to 4 inches in diameter. Pinch off the very top of the cutting to encourage it to develop branches.
How to Care for Rosemary (Salvia rosmarinus)
To keep Rosemary (Salvia rosmarinus)happy, give it six to eight hours of full sunlight each day. When growing it indoors, place it in a south-facing window for bright light, but don't let it get too hot.
Grow Rosemary (Salvia rosmarinus) in sandy, well-draining soil. This plant is native to the rocky hillsides of the Mediterranean and doesn't do well if its roots stay wet.
Water Rosemary (Salvia rosmarinus) deeply once or twice a week depending on weather conditions. Let the soil dry between watering. Keep the soil moist but do not over water to avoid root rot disease.
Temperature and Humidity
Outdoors, Rosemary (Salvia rosmarinus) can tolerate high temperatures and a wide range of humidity. Most varieties are hardy only down to 30 degrees Fahrenheit. Where temperatures dip below 30 degrees, rosemary plants will have to spend the winter indoors. In this case, it's easier to grow your rosemary in a container all year. Since rosemary likes it on the dry side, terra cotta pots are an especially good choice. Just be sure the plants don't bake and completely dry out while outdoors during the summer.
Not heavy feeders, Rosemary (Salvia rosmarinus)plants enjoy a periodic foliar feeding with fish emulsion fertilizer will keep plants looking evergreen. In spring, get plants off a good start by fertilizing with a slow-releasing fertilizer.
It's a good idea to prune newly planted Rosemary (Salvia rosmarinus) plants to encourage strong, bushy growth.
Established plants need little in the way of regular pruning, apart from removing wayward or overly long shoots. But cutting back plants by around one-third will help prevent plants growing too tall. Prune immediately after flowering.
Rosemary does not readily re-shoot from old wood, so never prune old, brown, leafless stems - otherwise the plant will die. Old, neglected plants are best replaced with new ones.
Pests and Diseases
The biggest problem with growingRosemary (Salvia rosmarinus) indoors is getting the humidity level right. High humidity and poor air circulation commonly result in powdery mildew on rosemary plants.1 Powdery mildew is a white, powdery fungus that can develop if the surrounding air is humid and there is not enough air movement. On the other hand, too little humidity will desiccate the leaves and quickly kill the plant.
Powdery mildew won't kill your rosemary outright, but it will weaken the plant.3 Try to balance the humidity by misting the leaves regularly but allowing the soil to dry somewhat between watering. In addition, keep the plant in sunlight and, if necessary, run a fan for a few hours a day to create a breeze.
Also, be on the lookout for aphids and spider mites.4 These pests seem to live on houseplants for the winter. Catching them before a total infestation will make them easier to control. Repeated spraying with insecticidal soap, per package directions, should take care of the problem.
Varieties of Rosemary (Salvia rosmarinus) to Try in Your Garden
dark blue flowers and fine needles
‘Lady in White’
its upright habit makes it useful as hedging
small pale pink flowers and upright habit
blue flowers, grows well in pots
‘Miss Jessopp’s Upright’
blue flowers and upright stems
highly aromatic with medium-blue flowers
Rosemary (Salvia rosmarinus) FAQ
Will Rosemary grow with the other herbs in my herb garden?
Unlike most herbs that live for only one season, rosemary is an evergreen shrub in zone 8 and farther south. For that reason, you should choose a location where it can continue to grow for years to come. It thrives in a sunny, well-drained location where it will reach up to 3 feet tall and wide. You can place it near the gate to your vegetable garden or as part of your home landscape. Because it is so fragrant when touched, it is a nice addition near a sidewalk or porch.
Can I trim rosemary anytime, or is there a recommended time?
As with any culinary herb, you should cut fresh, flavorful foliage whenever you need it. Plants do well with a heavy pruning anytime from early spring to midsummer. Try not to cut into stems that are dark and woody; these are less likely to sprout new growth than the younger wood. Remember that rosemary will never have a perfectly round silhouette, because it is the nature of the plant to have upright stems. However, the overall habit of the plant can be thicker with pruning to encourage branching.
I grow rosemary in a large pot and left it out over the winter. Should I cut the plant back or wait for the new growth?
Early spring before growth begins is a good time to prune any evergreen, and that includes rosemary. Remove any dead, leafless stems first, and then prune to improve the shape of the plant. Avoid cutting stems that are very old, as they may not sprout new shoots are readily as younger stems. However, if your plant is nicely shaped and you are happy for it to continue growing larger, remember that pruning is not a necessity. Note: when rosemary is grown in a container, do not let it dry to the point of wilting. It may not recover.