Rosemary, Rosmarinus officinalis, is a small shrub with many virtues that needs no introduction. Its persistent, aromatic grey foliage, with undeniable ornamental appeal, helps provide structure to the garden all year round. Its blue flowers in spring in the north of the country, and from late winter or even year-round in the south, are highly attractive to pollinators.

You'll find it in the vegetable garden, of course, but also in rockeries or along pathways. As the quintessential Mediterranean plant, it thrives in dry soil and is remarkably low-maintenance, though it dislikes waterlogged conditions.

It is used in cooking as well as for its medicinal properties. In short, it's a shrub you simply must have. Here are some tips if you'd like to propagate it to enhance different areas of your garden.

Techniques and Tips

Required Materials

As with any cutting, you'll need:

  • A good pair of secateurs, preferably cleaned and disinfected, to avoid transmitting diseases to your future plant. You can wipe the blade with a cloth soaked in alcohol.
  • One or more pots to hold the cuttings while they root.
  • Clay pebbles, which help retain moisture in the pot while promoting drainage.
  • A light growing medium

Growing Medium

Let's take a moment to discuss the growing medium. Rosemary is known to thrive in dry, relatively poor soil, so it's important to pay some attention to the "soil" to ensure the cuttings root well and the resulting young plants are healthy.

The ideal is to create a mix consisting of half compost—which will provide some nutrients—and half river sand to further improve drainage. It's advisable to moisten the growing medium beforehand, before planting the cuttings. Otherwise, you'll need to water your cuttings with a very fine spray.

rosmarinus officinalis, propagating rosemary
(photo cristina.sanvito - Flickr)

Several Methods

When to Take Rosemary Cuttings?

There are several methods for propagating rosemary. They are carried out at slightly different times of the year, from spring to autumn.

Rooting Rosemary in Water

Rooting cuttings in water is a method accessible to everyone. It is done in spring or summer on young, non-woody or slightly woody stems—those that haven't yet taken on a woody appearance and are still flexible.

  • Cut stems about 15 cm long. Prepare more than the number of cuttings you want, as it's unlikely you'll achieve 100% success. If you end up with more cuttings than needed, you can always swap them for other plants or seeds with fellow gardening enthusiasts.
  • Remove the leaves from the lower part and keep only a tuft of leaves at the tip.
  • Place the stem in a glass of water. Avoid tap water, which is usually quite chlorinated, or leave the glass of water out for a few hours before adding the cuttings to allow the chlorine to evaporate. Ideally, use rainwater, which is also less hard. If you can't collect any, bottled mineral water is another option.
  • Place the glass of water in a bright spot without direct sunlight.

Now you'll need to be patient and simply change the water in the glass daily to keep it clear.

After a few weeks, you'll see roots appear on the submerged part. Let them develop a bit before planting the cutting in a pot filled with a well-draining mix of sand and compost.

rosmarinus officinalis, propagating rosemary in water
Remove the lower leaves before placing your cuttings in a glass of water

Rosemary Propagation Under Cover

This technique uses semi-ripe stems, meaning those that have started to become woody, a process that typically occurs from August onwards, as the name suggests.

  • Take stems about 15 cm long. There's no need to use longer stems;
  • You can remove the leaves from the lower part or not—it doesn't make much difference;
  • Make a hole, with a pencil for example, and place the cutting inside.
  • Firm the soil around the stem so the growing medium adheres well. Water lightly if the medium wasn't pre-moistened;
  • Place a cloche, a cut-off water bottle, or a plastic bag supported by four small stakes over the top to prevent it from touching the cuttings. This creates a microclimate conducive to rooting by maintaining humidity around the plant and trapping warmth from this mini greenhouse effect. Place the pot in the shade to avoid harsh sunlight.

After about a month, you should see new shoots on the stems, a sign that the cuttings have taken well.

rosmarinus officinalis, propagating rosemary under cover
The plastic bags acting as cloches are held upright with stakes (photo cristina.sanvito - Flickr)

Heel Cutting for Rosemary

Heel cuttings are taken from semi-ripe stems—those that are starting to harden and take on a woody appearance. This is done in late summer or early autumn.

  • Take a 25 cm stem with a semi-ripe side shoot. This side shoot will form the cutting, with a small part of the main branch retained at its base (the famous "heel").
  • Place the cutting in a pot and cover the base with a mix of compost and sand. Water if the growing medium isn't moist and place in the shade. Then, all that's left is to wait for rooting.

Keep your cuttings in a bright spot, protected from frost during winter. If you have a cold frame, that's ideal. Otherwise, place them near a window in an unheated room in northern regions. In milder climates, pots can overwinter under a tree, sheltered from direct sunlight.

When to Transplant Rosemary?

Planting out should be done the following spring, when the weather warms up.

When planting, remember to water well to help your plant establish.

These are the propagation techniques. But know that other options are available for multiplication: sowing seeds, of course, and also layering. Plenty of experiments to look forward to!

To Go Further