How to Grow and Care for Rosemary
Last Updated on May 13, 2024
Salvia Rosmarinus or Rosemary is a perennial plant. Provision of warm, bright, and dry conditions is a perfect set of mix for the plant to live for years. With its mind soothing aroma it is used for culinary and medicinal purposes. Rosemary has a moderate growth rate which remains almost dormant in winters.
It has pine like needle leaves that are green in color. The stems are woody and erect. In late spring the plant produces clusters of purple, blue and white flowers depending upon its variety. The plant is drought tolerant so, does not need watering on every alternate days.
Best Time of The Year To Plant Rosemary
Spring is the season for its bloom. So if you are trying to propagate this plant in your house indoor, place it near the south facing window. However it loves to be planted outdoor as warmth of the Sun, natural humidity level and even temperature are the favorable conditions for this plant to attain its maximum growth.
Zone 8,9, and 10 are warmer and are considered ideal for growing Rosemary. These zones have mild and shorter span of winters and longer period of summers. So, it remains evergreen in these regions and lasts throughout the year. In these areas the plant will grow around 12 inches in one summer.
Zone 5 and 6 have comparatively mild winters. In these regions you can bring your Rosemary indoors to protect it from harsh winter nights.
Ideal Site To Grow Rosemary
Choose the spot where direct sunlight of maximum 6 hours can hit your Rosemary. Make sure that the spot has excellent ability to drain excessive water. Besides, it must not be planted near the shady trees as it will stunt its growth.
Rosemary Plant Care
Light Conditions
Direct sunlight of maximum 6 hours is required by Rosemary to grow. Areas which are warmer have shown optimal growth even up the month of December. But in colder areas, drop in temperature below minus 20 degrees Centigrade is a time when u need to bring your plant indoor. Use of grow bulbs in cozy cloudy days may help in providing the plant enough light to perform its growth functions.
Soil Requirement
Rosemary has reacted well when compost made soil is used to give it a kick start. The soil must have PH in between 6 to 7.
Watering Regime of Rosemary
Rosemary never minds if you not water it for days. Use half knuckle test if you want to predict the thirst of your plant. If the finger comes up dry it means that it is time to fetch your plant with water. However water only to make the soil moist but not cloggy.
In winters it can go without water for 10 to 12 days. And in summer watering it once a week is required. Make sure to water the soil and not the foliage.
Temperature and Humidity
Being a heat tolerant plant Rosemary can sustain the temperatures as high as 80 degrees and as low as 20 degrees. Similarly, low level of humidity can positively contribute in giving your plant a healthy life.
The ideal humidity level for Rosemary is 45 to 55 percent. Do not choose the area where cluster of plants are grown as it may suffocate your Rosemary. This will effect the air circulation and rise the level of humidity that may results in root rot.
Fertilizer needs
Rosemary if provided nitrogen based fertilizer biannually will improve plants foliage and strengthen its roots. But be careful that overfertilization can decay the plant.
If the soil is already rich in nutrients there is no urge of using fertilizer. And avoid using it in winters.
Harvesting Rosemary
The plant can be harvested at anytime of the year. But, Spring is the time when its leaves have best aroma and taste. You can pick around 3-4 inches stem from the tip. Its leaves can be dried by hanging its stems in a well ventilated dry place and later on can be pruned on drying for preservation.
Growing Rosemary In Pots
Rosemary is an invasive evergreen woody herb. If you want to confine its growth, plant it in a pot. Even in frosty winters it will be easy for you to bring that pot indoors to protect it from harsh weather.
How To Propagate Rosemary
Propagation of Rosemary via seed
Although this method is not recommended, as growing Rosemary from seedlings is a slow process. In fact, the plants it produces takes very long to get mature. Some of them not even germinate.
If you want to grow Rosemary using its seeds. Follow the process below.
Keep in check the frost date of your area and get yourself prepared before.
Use potting mix made of 4 parts of compost, one part vermiculite, one part perlite, and two parts of peat moss.
Soak the Rosemary seeds for 24 hours before placing them inside potting mix.
Add seed-starting mix in a tray and disperse them at a distance. Put seeds on the soil mix and further add a layer of it on the seeds.
Now cover the tray with a plastic wrap on it. And place this tray in indirect light.
When you observe the seedlings are around 3 inches above the ground, this is the time to remove the plastic wrap.
Now put the tray in a place where direct sunlight can reach.
Move the seedlings to the planter in which you want to plant it.
Rosemary Propagation from Cuttings
This is most widely and effective method to grow multiple Rosemary from your existing plant.
Cut a mature stem that is 3-5 inches long.
Prune the leaves from the lower part of the stem.
Use transparent narrow neck container so that only lower part of the stem is dipped in water.
Add rooting hormone to help the stems generate roots.
Make sure to place the container in indirect light while the roots are propagating.
When you see tiny roots coming out of the stem’s lower part. Plant the stem in a potting mix in a pot that has fine drainage holes in it.
Be careful that the pot must not be containing any soil in it.
Now place this pot in a warm place where indirect sunlight can reach the pot.
Mist the potting mix daily to make sure the cutting is getting enough moisture to grow.
After 3 weeks gently pull out the cutting. If you find a resistance it means that roots have made their firm hold in the soil. Resistance is also an indicator that it is time to transplant this cutting in a planter.
How To Repot Rosemary
Rosemary is a root bound plant. Its pruning leads to stimulation of new stems and increase root production. So it is recommended to repot your rosemary in one size up planter for its better growth.
Make sure to use potting mix with perlite in it. It will give a loosen effect to the soil and improves circulation of air in the roots.
Repot it once every year in the spring. Do not repot it in the dormant period.
Pruning of Rosemary
Just like other plants pruning your rosemary positively contributes in your plant’s health. As it will give boost to its growth and will also help new stems to originate. Keep in mind that you do not cut more than one third of the plant as it will give shock to the plant and it may also become a home for pests and diseases.
Tips For Pruning
Do not prune your plant if it is already struggling through a disease.
Secondly, cut off the dead parts of the plant using sterilize scissors or hedge shears. They can also be used to create elaborate topiaries as well as to cut dead shrubs.
Trim in the spring season only when the plant is in its growing phase. Doing it elsewise will pose serious threat to its health. It may cause roots to decay and it may invite pests infestation.
How To Care For Rosemary In Winter
Rosemary needs frost protection. Specially in regions where temperature falls below 30 degrees Fahrenheit. Bring the planters indoors or under the shelter so that your plant may not get frost bite.
If you have planted Rosemary in garden borders, use frost protection row covers as they can maintain temperature and protect the plant from frost.
Similarly in winters if you have placed your Rosemary inside the house then it is recommended to put it near south facing window where it can acquire maximum sunlight.
Do not water your plant frequently in winters. As the evaporation rate is also low in cooler days. So water only when you observe outer layer of the soil is drying out.
Also use mulch to provide insulation to the roots in winter. Use compost, pebbles, or gravel for maintaining ideal environment for your Rosemary to sustain harsh winters.
Common Diseases in Rosemary
Powdery Mildew
As the name indicates powder like fungus scatter on the leaves. This is due to the less humidity and poor air circulation. Your plant might be suffocated in the company of other heavy and shady plants that is making your plant infected by this disease.
It usually attacks plant in wet and warm season when it is not getting direct sunlight.
This is not a threatening disease but it may weaken the roots over the period of time.
Prevention
Isolate the infected plant to the place with better ventilation.
Change the watering regime.
Tip : Use three tablespoons of baking soda, one table spoon of vegetable oil, and few drops of dish washing soap in 3 liters of water to make an anti-fungal, anti-bacterial solution.
Spray the solution on the rosemary leaves and stems and clean them with a soft cotton cloth.
Use this spray twice a week to get better results.
Fusarium wilt
This is a soil borne fungal diseases in which plants leaves will become yellow in color and starts wilting. It targets plants vascular system and blocks the passage of nutrients and water to the upper parts of the plant.
Prevention
Always use sanitize gardening tools to reduce the risk of infection.
Never overwater your plant because to much moist soil effects the plant from inside out and attract pests.
Always provide a space of feet in between the planters to allow circulation of air.
Root rot
Poorly drained moist soil is the reason behind root rot in many plants. Same is the case with rosemary, being a drought tolerant plant it can sustain without water for days. But a misfit watering regime to the plant will moisten the soil more than it needs to be and leads to root decay.
Prevention
Here is the tip to prevent this situation. Do not water the plant unless the soil gets dry.
Leaf spot
Leaf spot usually occurs when one or multiple cells of a leaf starts dying. It is a fungal disease that creates black spots or lesions on the surface of rosemary leaves.
Prevention
In order to avoid this calamity to happen, try not to water the plant from above. As it deteriorates its foliage and water stays at the leaves for longer time. This leads to develop fungus.
Secondly prune the leaves that are already defected.
Try bottom watering technique or wet the surface of the soil only to make it moist.
Allow better ventilation of air so that if foliage of Rosemary becomes dry.
In severe cases use fungicides to help the plant fight against the fungal invasion.
Pests That Can Attack Rosemary
Rosemary Beetles
Rosemary beetles are usually green or blue in color. Various factors are involved that why these insects are attracted to Rosemary. The plant emits certain type of aroma that these beetles love to culture in. They attack their foliage and damages their leaves.
But there is nothing to worry about. Their spread can be controlled by insecticidal spray.
Frequent inspection must be done in order to control their infestation before it become un controllable.
Aphids
Aphids are found on newly grown stems and leaves of rosemary. They feed on plants cell sap. Their attack can make the plant weak and gradually leads to its death.
Insecticidal spray can help in order to push these creature away form your plant.
Rosemary Leafhoppers
They are also tiny creatures found on under side of Rosemary stems and leaves. They also extract sap from the plant and produce black discoloration in stems and leaves.
White Flies
White flies like other pests extract nutrients from rosemary foliage. But they can be wiped off easily with a wash or pest preventing spray can be used to repel them.
Companion Plants for Rosemary
Companion planting is done to help the plants with similar needs benefit and prevent each other. Rosemary has number of folks in this regard.
Aubergine , beans, beets, brassicas, chives, lavender, marigolds, oregano, garlic, pepper plants and many others have a symbolic relationship with Rosemary.
Each of them contribute positively to others growth. Rosemary having strong fragrance act as a deterrent for these plants to repel the pests that can pose threats for their existence.
On the other hand these companion plants attract beneficial insects that play essential role in rosemary to grow as a healthy plant.
Benefits of Rosemary Plant
Rosemary has been traditionally used due to its medicinal and culinary benefits. It has anti oxidant, anti fungal and anti viral properties. Due to its pleasant smell it is used by cosmetic industry in various skin care products .
For culinary purposes it is used to enhance the taste and aroma of the dishes like soups, sausages, and stakes etc.
Being an antioxidant it repairs the damage cells and fight against the free radicals present in the body and also boost immunity.
Rosemary oil extract has been recommended to treat joint inflammation.
Rosemary oil has proven benefits to stimulate the dormant hair follicles and treat bald patches.
Rosemary water is sprayed twice a day to overcome hair thinning.
A few drops of its oil is used to treat digestive problems.
Recent studies have also shown that it has certain properties to prevent the activation of cancer cells.
Rosemary leaves infused in water helps to control type 2 diabetes.
Studies have also shown that its essential can be used for food preservation.
Caution: Make sure to use Rosemary with consultation of your physician, As it has potential drug interactions that can be harmful.
Conclusion
Upbringing Rosemary as a member of your garden is not a difficult task to do. Even it can be planted by a novice gardener due to its less demanding nature. It can be nurtured easily by paying heed to some of the factors. Give your plant a bright, un shady, well drainable soil, with a moderate watering routine and see it blooming throughout the year.
Besides, watch over the plant on weekly basis to keep the pests and diseases at bay. Its beautiful silvery green foliage along with captivating flowers not only enhance your garden’s beauty, but will also bring flavor to your dishes.