Guide to Cultivating a Thriving Rosemary Garden: Tips & Techniques for Novices and Experts Alike

Are you considering introducing a new herb to your garden this season? Rosemary, known for its aroma and flavour, can be grown as an herb and a decorative garden plant. This evergreen shrub produces beautiful purple flowers in the summer and serves as a pollinator-friendly addition to your landscape.

Growing rosemary generally does not pose many difficulties, and once it has established itself, this perennial woody shrub thrives for many years. To get the most enjoyment out of its aromatic oils, plant rosemary near a walkway so that each time you pass by, the leaves release their pleasant scent. Keep reading to discover how to grow rosemary, as well as how to care for and harvest it.

About Rosemary Plant

Rosemary (Salvia rosmarinus, previously known as Rosmarinus officinalis) is a perennial herb that forms a compact small to medium-sized woody bush, and there is also a trailing variety available. This herbaceous shrub belongs to the sage family and thrives alongside other Mediterranean herbs like lavender and thyme. Its needle-like leaves resemble tiny pine trees and emit a potent scent that keeps pests away from other plants. The plant produces bluish-purple flowers in early summer that draw in pollinators from various distances.

The rosemary plant has been utilized for thousands of years in both culinary and medicinal applications. This flavorful and beneficial herb offers numerous health advantages and aesthetic purposes, making it a valuable addition to your kitchen and beauty routine.

When To Plant

These popular rosemary plants are pretty hardy, and caring for them is straightforward, whether grown indoors or outdoors in an herb garden. With their Mediterranean roots, these plants thrive in hot and dry weather conditions.

In Canada, rosemary can be planted as early as the end of April, but it is essential to wait until there is no risk of frost remaining. As a perennial plant, rosemary will grow back each year; however, it may not withstand Canadian cold winters. Particularly in Ontario, it is recommended to grow rosemary as an annual or in a portable container that can be relocated indoors before the onset of the first frost.

A person is planting a rosemary plant in a pot.


How To Plant Rosemary

Growing rosemary from seed is possible during early spring, but starting with a starter plant is generally quicker and more straightforward. Many gardeners choose to establish their rosemary patch by acquiring a plant from a nursery or garden store or by taking a cutting from an existing plant.

To grow rosemary, it is essential to plant it in well-draining soil with a slightly acidic pH level, ideally between 6.0 and 7.0, and in a location that receives full sun. New rosemary plants may struggle if their roots are constantly wet, especially during winter. To avoid this issue, consider growing rosemary in a container for the first couple of years or keeping a cutting from an exterior plant indoors.

If soil is dense or clay-like, amend it before planting by incorporating organic materials like compost or peat moss. Also, ensure that no taller trees or shrubs nearby could shade the rosemary.

It is recommended to space rosemary plants at a distance of 2 to 4 feet apart. Since some plants can expand to a width of more than 4 feet, it is preferable to provide rosemary with ample space.

Propagate Rosemary

If you’re interested in propagating your rosemary plants, the most effective method is to begin with a cutting. This is not only a cost-efficient way to obtain a new plant but also encourages more branching and denser growth in the mature plant. Spring or summer are the ideal periods to take a cutting for rosemary plants. Here’s how:

  • Select a healthy stem that is a few inches long, preferably new softwood growth for optimal results.
  • Remove the leaves on the lower part of the stem, ensuring at least five leaves remain.
  • Apply rooting hormone to the cut end of the stem.
  • Place the cutting into a moist soilless potting mix inside a small container with drainage holes.
  • Position the container in a warm area with bright, indirect sunlight. Mist the cutting daily and keep the growing medium moist.
  • After two to three weeks, gently pull on the stem to check for root development. If you feel resistance, roots have formed, and the cutting is ready for transplanting.

Grow Rosemary From Seeds

Growing rosemary from seeds can be challenging due to low germination rates and slow-growing seedlings. To start, plant seeds indoors 2 to 3 months before the last average frost-free date. Sow the seeds in pots or trays filled with seed starting mix and lightly cover them with the mix. Cover the trays with plastic wrap and place them in a warm room or on a heat mat, as rosemary seeds require temperatures between 65-80 degrees F for germination. Ensure the soil remains moist.

After 2 to 4 weeks, when the seeds have germinated, remove the plastic cover and move the trays to a location with bright light. Once the rosemary plants have grown several inches tall, transfer them to outdoor beds or pots.

Grow Them In Pots

Cultivating rosemary in pots enables you to relocate it indoors during cold weather. Additionally, you can place the containers on your patio or deck, close to your kitchen, for convenient access while preparing meals.

When growing rosemary in a container, use a light, well-draining potting mix. Choose a pot slightly bigger than the plant’s root ball, ensuring it has drainage holes. An unglazed clay container is the preferred choice, as it helps excess moisture in the soil to evaporate through its walls.

Potting and Repotting Rosemary

Plan to repot the rosemary every year into a container one size larger, using fresh potting mix. Spring is the ideal time for repotting. Carefully remove the plant from its previous container, and place it at the same depth in the new one, surrounding it with soil.

After the rosemary has been placed in a larger pot and new growing medium, you can trim off soft growth to balance branches and shape the plant as the rosemary grows. Additionally, consider using nitrogen-rich fertilizer for the potted plants.

A hand is holding a bowl of rosemary plant

How To Harvest Fresh Rosemary

For the freshest taste, it’s ideal to harvest young stems and leaves of rosemary sprigs, preferably during spring and summer when the plant produces soft new tips. Gently pull small sprigs away from the main stem or use secateurs to remove large branches for roasting.

To dry rosemary, form bunches and hang them upside down in a dark, warm area. Once the stems are dry, remove the leaves and store them in a sealed jar. Alternatively, you can freeze rosemary sprigs, preserve them in vinegar, or utilize them for flavouring oil or butter.

Common Pests & Problems

Diseases caused mainly by overwatering or damp conditions, like root rot and botrytis, can harm your rosemary. Insufficient air circulation and elevated humidity levels contribute significantly to issues like powdery mildew and can result in a loss of flavor in your growing herbs.

In addition to these diseases, look for pests like spider mites, mealybugs, whiteflies, and aphids. These insects can harm the leaves of your rosemary plant. To treat these pests, consider removing them by hand or using an insecticide. Additionally, planting herbs known to repel pests, such as basil or mint, can be helpful.

Rosemary Care Tips

Light, Temperature, and Humidity

Rosemary prefers to have at least six hours of direct sunlight or natural light on most days, as it does not tolerate shade. This herb thrives in various outdoor conditions, including hot, cool, dry, or wet weather. However, when grown indoors, rosemary might become dry and brown, so placing the pot on a tray with pebbles and water while keeping it in a sunny yet cool area can maintain its humidity. It is also necessary to bring potted rosemary plants inside during the winter months.


Water rosemary carefully, as they possess good drought tolerance once they mature. To avoid root rot or a woody, tough appearance, it is better to underwater rather than overwater these shrubs. When the top few inches of soil have dried out, water the rosemary so that the soil is consistently moist but not drenched.


Prune rosemary as needed to control its growth once the plant has finished blooming. During the growing season, you can clip stems to use fresh rosemary or gather a bunch to dry in autumn. However, avoid removing more than a third of the shrub at once, as this can place stress on the plant and make it susceptible to diseases and pests.


Prior to planting, incorporate several inches of mature compost or other rich organic matter into the soil. In spring and summer, nourish rosemary with an organic, nitrogen-rich fertilizer, adhering to the recommended amount specified on the product label. Refrain from using chemical fertilizers, particularly if you intend to use rosemary cuttings in cooking.

A woman is holding a wooden crate with rosemary plants in it.

Rosemary Varieties

Numerous types of rosemary exist, with some being more suited for cooking purposes while others are ideal for landscaping.

Prime Rosemary

The culinary variety Prime Rosemary offers quick and dependable germination. Its edible flowers, known for their strong taste, are commonly used as garnishes. If you enjoy using aromatic herbs in your cooking, consider growing this type of rosemary.

Blue Boy

Blue Boy, a dwarf variety, grows to a height of six to eight inches and is ideal for rock gardens and containers. Although small, the leaves are tasty, producing intensely fragrant tiny blue flowers.

Tuscany Blue

Blue Tuscany is a favorite culinary variety among chefs. This plant can grow up to four feet tall and features deep blue flowers. It thrives in strong sunlight and can be successfully grown in containers despite its height.

Miss Jessup’s Upright

Miss Jessup’s upright is a popular culinary plant that can grow up to four to five feet in height and about two feet in width. With slender branches and broad leaves, it features delicate pale blue flowers, making it an attractive addition to formal or English herb gardens.

Pine-Scented Rosemary

The landscaping variety of pine-scented rosemary is often utilized for topiaries. This cultivar is commonly trimmed into a Christmas tree shape and sold during the holiday season. The leaves of this pine-scented plant are more narrow and needle-like compared to culinary varieties. However, despite its pleasant piney fragrance, it is not a suitable option for cooking.

Trailing Rosemary

Among the various types of creeping rosemary, trailing or creeping rosemary stands out as the most visually striking. This variety can be grown in a window box or container, allowing it to cascade beautifully over the edge. Adding this plant to a wall or fence creates an impressive waterfall effect, making it an excellent choice for landscaping.

Final Thoughts

The grounding, stimulating, and inspiring rosemary herb is a fantastic addition to your garden, providing numerous health benefits. When cultivating this classic Mediterranean herb, it is crucial to honour its origins by planting it in well-drained soil, ensuring it has minimal excess water, and placing it in a warm and sunny location. By doing so, you will be able to thoroughly enjoy a soothing cup of rosemary tea while reaping its many rewards.

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