Rosemary, a beautiful and fragrant herb, is a drought-tolerant icon. Rosemary thrives in hardiness zones 7-11.
Poor soils, low fertility, or drought do not bother this plant. It is more picky about the amount of sunlight.
Here’s everything you need about Rosemary’s light requirements if you are trying to decide where to plant it in your garden.
The Answer in Detail
Rosemary, a native Mediterranean plant that loves the sun, grows in gardens with lavender and thyme. It can’t succeed at its maximum potential without direct sunlight. In the video below, we talk about it at around 1:19.
Keep Rosemary away from trees and structures that can shade it out. The plant can be planted indoors, in a container, if it gets bright direct sunlight from a window facing south. It would help if you only gave Rosemary shade in scorching southern climates.
Learn why Rosemary requires so much sunlight and how you can ensure it receives the light it needs.
Sunlight and Fragrance
Terpenes, the volatile essential oils of Rosemary, are responsible for its earthy aroma. These oils are found in leaf structures known as trichomes. When plants receive more light, they naturally produce more trichomes. More sunlight means stronger-smelling Rosemary!
According to this study, Rosemary produces essential oils that are deliciously scented to protect the leaves from UV damage. It also helps repel pests.
Rosemary produces more aromatic oils when it is exposed to maximum light. Rosemary’s protective oil explains why the plant can survive intense summer sun on exposed slopes near the Mediterranean Sea.
Only extreme heat will cause the plant to produce less volatile oil. Rosemary’s fragrance can be lost at temperatures above 95degF. Planting in the cool, dappled shadow is recommended only in the hottest climates in southern regions.
When Rosemary Doesn’t Get Enough Sunshine
The happiest rosemary shrubs are those that bask in the sun all day. If Rosemary is given enough sunlight, it retains its fragrance and vigor. The plant may die if it is in too much shade.
Fixing Light Deficiency
You don’t need to start from scratch if you have a sad rosemary plant that needs more light. These herbs are willing to move and will quickly recover. You can also fix any soil and water problems your rosemary plant may have by transplanting it to a more sunny area.
In Northern Climates, provide Maximum Sun.
Rosemary, a perennial that is delicate and prone to disease, still thrives in many gardens of the north. It is essential to plant your Rosemary in an open space because of the angle at which the sun shines in the north during winter. The shade from large shrubs or trees can drastically reduce the growth potential of Rosemary.
Exposing Rosemary to full sunlight is essential if you live in an area that experiences heavy rains, such as the Pacific Northwest.
Choose the area that faces south, where the shrub will not be shaded. You will avoid many headaches by planting Rosemary in an exposed area. This reduces the chance of foliar diseases.
In Southern Climates, Provide Afternoon Sun Shade
Hardiness Zones 10 and 11 are the only zones where we recommend that Rosemary be shaded. Rosemary is not bothered by the heat of summer but will appreciate some shade in the afternoons, especially in the Southwest and Southeast.
The plant will not be scorched by the intense summers of tropical or desert areas if shaded in the afternoon. The heat and dryness of these regions do not harm this herb. In hotter areas, however, it will appreciate a little shade. It will still look and smell great.
Rosemary can grow in low light.
Although Rosemary grows slower in the shade, it can tolerate areas of lower light with 4-6 hours of direct sunlight. In northern climates, dappled shade or partial shade will reduce the fragrance and strength of Rosemary.
Rosemary is often protected from the harsh sun and heat in hot climates like those in the Southwestern and Southeastern United States of America.
Final Thoughts
Rosemary can be a tricky plant but will suffer under low light conditions. Give Rosemary the sunlight and well-drained ground it loves, and it will continue to produce fragrant leaves and flowers.
