How to Grow and Care for Rosemary
Last Updated on June 20, 2024
Salvia Rosmarinus or Rosemary is a perennial plant. The 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 winter.
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 day.
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 indoors, place it near the south-facing window. However, it loves to be planted outdoors as the warmth of the Sun, natural humidity level and even temperature are favourable 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 winters and longer periods of summer. 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.
Where to Grow Rosemary Plant
Choose the spot where direct sunlight of a maximum of 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 Complete Guide
Light Conditions
Direct sunlight of a maximum of 6 hours is required by Rosemary to grow. Warmer areas have shown optimal growth even up in December. But in colder areas, drop in temperature below minus 20 degrees Centigrade is a time when u need to bring your plant indoors. The 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 a PH between 6 to 7.
Watering Regime of Rosemary
Rosemary never minds if you not water it for days. Use the 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 makes the soil moist but not cloggy.
In winter 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 temperatures as high as 80 degrees and as low as 20 degrees. Similarly, a low level of humidity can positively contribute to giving your plant a healthy life.
The ideal humidity level for Rosemary is 45 to 55%. Do not choose the area where clusters of plants are grown as it may suffocate your Rosemary. This will affect the air circulation and raise the level of humidity which may result in root rot.
Fertilizer needs
Rosemary if provided nitrogen-based fertilizer biannually will improve plant 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 to use fertilizer. And avoid using it in winter.
Harvesting Rosemary
The plant can be harvested at any time of the year. But, Spring is the time when its leaves have the 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
However this method is not recommended, as growing Rosemary from seedlings is a slow process. The plants it produces take very long to mature. Some of them do 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 beforehand.
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 the potting mix.
Add the seed-starting mix to 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. 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 the 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 a transparent narrow-neck container so that only the 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 does not contain 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 Report Rosemary Plant
Rosemary is a root-bound plant. Its pruning leads to the stimulation of new stems and increases root production. So it is recommended to report your rosemary in one size-up planter for its better growth.
Make sure to use a potting mix with perlite in it. It will have a loosening effect on the soil and improve the circulation of air in the roots.
Report it once every year in the spring. Do not report it in the dormant period.
Pruning of Rosemary
Just like other plants pruning your rosemary positively contributes to your plant’s health. As it will give a 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 with a disease.
Secondly, cut off the dead parts of the plant using sterilised 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 otherwise will pose a serious threat to its health. It may cause roots to decay and it may invite pest infestation.
How To Care For Rosemary In Winter
Rosemary needs frost protection. Especially in regions where temperature falls below 30 degrees Fahrenheit. Bring the planters indoors or under the shelter so that your plant may not get frostbite.
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 winter if you have placed your Rosemary inside the house then it is recommended to put it near a south-facing window where it can acquire maximum sunlight.
Do not water your plant frequently in winter. 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 to maintain the 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 are making your plant infected by this disease.
It usually attacks plants in wet and warm seasons when it is not getting direct sunlight.
This is not a threatening disease but it may weaken the roots over some time.
Prevention
Isolate the infected plant to a place with better ventilation.
Change the watering regime.
Tip: Use three tablespoons of baking soda, one tablespoon of vegetable oil, and a few drops of dishwashing soap in 3 litres 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 disease 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 sanitised gardening tools to reduce the risk of infection.
Never overwater your plant because too much moist soil affects the plant from the inside out and attracts 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. The same is the case with rosemary, being a drought-tolerant plant it can sustain itself without water for days. But a misfit watering regime to the plant will moisten the soil more than it needs to be and lead 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 start dying. It is a fungal disease that creates black spots or lesions on the surface of rosemary leaves.
Prevention
To avoid this calamity from happening, try not to water the plant from above. As it deteriorates its foliage and water stay on the leaves for a longer time. This leads to the development of fungus.
Secondly, prune the leaves that are already defective.
Try the 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. Various factors are involved in why these insects are attracted to Rosemary. The plant emits a certain type of aroma that these beetles love to culture in. They attack their foliage and damage their leaves.
But there is nothing to worry about. Their spread can be controlled by insecticidal spray.
Frequent inspections must be done to control their infestation before it becomes uncontrollable.
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 lead to its death.
Insecticidal spray can help to push this creature away from your plant.
Rosemary Leafhoppers
They are also tiny creatures found on the underside of Rosemary stems and leaves. They also extract sap from the plant and produce black discolouration 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 several 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 contributes positively to others’ growth. Rosemary having strong fragrance acts as a deterrent for these plants to repel the pests that can pose threats to their existence.
On the other hand, these companion plants attract beneficial insects that play an 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 the cosmetic industry in various skin care products.
For culinary purposes, it is used to enhance the taste and aroma of dishes like soups, sausages, stakes etc.
Being an antioxidant it repairs the damaged cells fights against the free radicals present in the body and also boosts immunity.
Rosemary oil extract has been recommended to treat joint inflammation.
Rosemary oil has proven benefits in stimulating the dormant hair follicles and treating bald patches.
Rosemary water is sprayed twice a day to overcome hair thinning.
A few drops of its oil are 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 the 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 bright, unshady, well-drainable soil, with a moderate watering routine and see it blooming throughout the year.
Besides, watch over the plant every week to keep the pests and diseases at bay. Its beautiful silvery green foliage along with captivating flowers not only enhances your garden’s beauty but will also bring flavor to your dishes.
