How to prune rosemary

Rosemary is a wonderfully fragrant herb that is both easy and forgiving to prune. These small woody plants are generally cut back once a year to keep the branch structure from becoming overly woody and to promote growth. Keeping your rosemary well-pruned can also help increase airflow around the foliage and reduce disease. Let’s look at exactly how to go about pruning this lovely herb!

Pruning outdoor rosemary shrubs

The basics of pruning rosemary

A rosemary shrub is generally given one main pruning each year in the spring. The main stems of the plant can be pruned back by one-half of their length. While pruning is not strictly necessary, it keeps the plant compact, allows for airflow, and encourages fresh growth (rather than woody growth). Some portions of the overwintered stems are typically left on the plant since this small shrub flowers on old growth.

The purpose of pruning rosemary is to keep the stems nice and uniform so that the plant doesn’t get too woody or lanky, and to remove spent flowers. Pruning gets rid of the dead ends of the rosemary plant, much like getting a haircut.

By cutting off the ends, you’re allowing it to grow back healthier. The same thing goes for pruning a rosemary. However, pruning is not necessary unless you have a specific desired look for your plant or want to keep the ends healthy.

“Rosemary may be pruned severely to shape the plants or to keep them from interfering with nearby herbs. Pruning is also a good method of maintaining airflow around and through rosemary plants, an important cultural feature that helps prevent foliar diseases that cause wilt.”

Grow Your Own Herbs: The 40 Best Culinary Varieties for Home Gardens, by Susan Belsinger & Arthur O. Tucker
Pruning outdoor rosemary plants

When to prune rosemary

The best time to prune your rosemary is in the spring or summer. However, you can continue pruning depending on your desired look until 4-6 weeks before the first frost. If you prune too late in the season, your rosemary plant may promote growth that is susceptible to winter damage. On the other hand, pruning rosemary until 4-6 weeks before the first frost allows the ends to harden and protect the new healthier growth. 

How to prune rosemary in a pot

Many people plant rosemary in pots and keep them as indoor plants for culinary use. Potted rosemaries are generally pruned each spring. Each stem can be shortened to up to half of its length. This will keep the potted shrub compact and encourage fresh new growth during the upcoming growing season.

Pruning your rosemary in a pot is essential for keeping the plant healthy and preventing it from becoming too woody. As your rosemary plant grows from a small sapling to a larger plant, you will need to prune the branches to keep the plant looking bushy. Rosemary grows reasonably quickly and can get out of hand if not pruned often enough.

Although not susceptible to frost like an outdoor plant, rosemary planted in a pot still does better when pruned in the spring and summer. Pruning during this time allows the plant to harden existing growth and prevent early flowering. 

Pruning rosemary plants

How to prune rosemary trees (standard topiary)

Pruning a rosemary tree as a topiary requires a bit more imagination and practice than trimming rosemary in a pot or as a bush. Topiary is the practice of shaping your tree by pruning it to develop into a particular shape (usually a lollipop-style like a lavender tree). The more consistently you prune your tree, the better chance it has of maintaining a specific form.

When pruning a rosemary tree, make sure you have sharp, clean scissors that will cleanly cut off any branches that don’t fit your desired shape. Just make sure to avoid pruning your rosemary when it’s flowering, so that you don’t promote any new blooms. 

If you want your rosemary tree to grow upright, start by cutting the side branches so that the plant learns to grow upward. Once your tree grows to your desired height, you can start shaping the tree into your desired shape. Read more about creating a rosemary tree topiary. You can also do a triangular-shaped rosemary Christmas tree!

How to prune rosemary Christmas trees

During the holiday season, many people purchase rosemary Christmas trees for culinary purposes or to add fragrance to their homes. However, if you’re planning on keeping your rosemary plant for longer than the holiday season, you may need to prune your tree. 

Since a rosemary Christmas tree is already in the shape of a tree, the pruning process is much easier. First, follow the natural cone shape of the branches and snip off any dead ends. After pruning, mist the leaves to provide moisture. Repeat the pruning and misting process every couple of weeks to keep the plant healthy. The tree will likely need its first annual prune during next year’s spring.

Large rosemary bush
Rosemary shrubs can grow quite large outdoors!

How to prune an outdoor rosemary bush

Outdoor rosemary bushes can grow up to 5-6 feet tall if not regularly pruned. If you aren’t concerned about the height of your plant, there’s no need to prune it. However, maintaining a shapely bush starts with pruning each year. It is especially important to remove any branches that did not survive harsh winter temperatures (rosemary is susceptible to winter damage).

When pruning your rosemary bush, cut back the main stems by one-half. You can propagate new plants with the leftover stem cuttings by planting the stem cuttings with a rooting hormone to encourage growth. 

Outdoor rosemaries can also be planted in a row and trained into a hedge shape. These plants are typically not pruned until the plants are slightly larger than the desired hedge height/width. Once the plants have reached this size, they can be “topped” slightly below the desired hedge top level. The sides can be similarly sheared. Rosemary hedges are typically then given one hard pruning each spring to keep them shapely, although they can be given light prune or trims during the growing season to keep the formal look.

How to prune rosemary

Does pruning rejuvenate an old rosemary plant?

Pruning can rejuvenate an old rosemary plant. If your rosemary bush is looking sad, start by cutting the entire plant back in late winter or early spring to encourage new growth using pruning shears. Keep in mind; to leave the lowest cluster of foliage intact. Rosemary cannot grow from dead wood, so you want to avoid pruning back too far and removing all of the living branches.

If your rosemary plant looks dead after a harsh winter, don’t prune back the dead or faded flowers or broken or diseased branches of the tree until the weather warms up. The “dead ends” of the branches protect the healthy branches during the winter, so you want to leave those intact until warmer weather arrives. 

Creeping rosemary plant in pot

How do I prune creeping rosemary?

If you have a creeping Rosemary variety the pruning process will look slightly different. Like upright rosemary cultivars, cutting back one-half of the main stem in the spring and summer allows the ends to harden before the first frost. Use pruning shears.

The difference in pruning woody stems from the shape of the plant. Since the branches are not upright, they drape over ledges and rocks. If you want your creeping rosemary to grow over a particular area, trim back the branches that do not fit your desired shape. Pruning in this fashion trains the plant to grow over a specific structure. 

Creeping rosemary
Mary Jane Duford
Mary Jane Duford

Mary Jane Duford is a quintessential Canadian gardener. An engineer by trade, she tends to an ever-expanding collection of plants. In her world, laughter blooms as freely as her flowers, and every plant is raised with a dash of Canadian grit.

Mary Jane is a certified Master Gardener and also holds a Permaculture Design Certificate. She's also a proud mom of three, teaching her little sprouts the crucial difference between a garden friend and foe.

When she's not playing in the dirt, Mary Jane revels in her love for Taylor Swift, Gilmore Girls, ice hockey, and the surprisingly soothing sounds of bluegrass covers of classic hip-hop songs. She invites you to join her garden party, a place where you can share in the joy of growing and where every day is a new opportunity to find the perfect spot for yet another plant.

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