Plants for Free: How to Propagate Rosemary from Cuttings
New Rosemary Plants for Free
If you have an established rosemary plant, you can use it to propagate dozens of new plants for practically nothing. Propagating is essentially cloning the parent plant and the way that happens is by encouraging pieces of the stem to form their own roots. Rosemary is one of those herbs that roots fairly easily so if you try this method, you should have loads of new plants within a couple of months.
Watch the video below to see the process and what a plant I propagated a year ago looks like. The full set of written directions is laid out below.
- Rosemary cuttings
- Rooting Hormone Powder
- Terracotta pots
- Peat-free Multipurpose compost — get from a garden center
- Plastic ziplock bag
Step 1: Source your Cuttings
You begin the process by taking a decent sized cutting from the parent plant. It should be a healthy stem that’s grown in the current year and should be a good length as well — mine below is about 18″.
The reason you might want to propagate rosemary is that you don’t have your own plant. In this case, ask a friend who has a mature rosemary plant that you can take a cutting from. I dare say that someone will ask whether cut rosemary from the supermarket will grow. I’ve never tried but if it’s fresh enough it could work.
Step 2: Potting Mixture
Some cuttings you could just stick into ordinary soil and they’ll root. However doing so makes it more likely that you’ll lose cuttings to rot, fungus, pests, and other issues.
The best substrate to use when propagating plants is one that is high in drainage with less emphasis on nutrients. Your cuttings won’t need fertilizer or feeds and by the time their roots develop you move them on into new compost.
To create good drainage I create my own mix using one part Perlite and two parts multi-purpose compost. Technically you could root them in pure Perlite or sand though.
Step 3: Prepare the Cuttings
If you want further directions on this step, watch the video at the top of this article.
What we do next is cut that single rosemary stem into several pieces — each one can grow into it’s own plant. Starting from the bottom, trim the original cut up to a fresh leaf node. A leaf node is where leaves are growing out of the stem.
Discard that end piece you’ve just cut off. Then cut the first segment using a sharp knife. It should be a minimum of 3″ long but far better to be 4-5 inches and you again cut up to a leaf node. Strip the leaves from the bottom of the cutting leaving the last bunch of leaves growing at the top. This length that you strip of leaves should be about 1.5-2.5 inches long.
A note on orientation: the bottom of each cutting should be from the lower part of the stem. If you mix this up then the cuttings will not grow. It’s like planting a plant upside down.
Step 4: Rooting Hormone Powder
Cuttings can develop roots all on their own but if you want to stimulate that action yourself, use Rooting Hormone Powder. There are other materials that can be used but this is the one I use and have a high success rate with.
Assemble your cuttings and have your terracotta pots filled with the potting mix. Next, dip the end of each cutting into the hormone powder and then gently slide them into the pot along the outer edge. Leave about an inch and a half between cuttings.
Note: The more professional way to slide cuttings into the pot is by making a hole with a dibber (i.e. pencil) and then putting the cutting in that way. I never do it that way but haven’t had any issues.
Step 5: Propagating
After the cuttings are arranged in the pots, give them a good drink of water and let the water drain out fully. Then place a plastic bag over the pot to make it into a mini greenhouse.
The cuttings will form good root systems within 4 to 8 weeks and during that time you need to keep the compost moist. Not sopping wet but just moist enough that you can feel it with your finger. You’ll know that your cuttings have rooted when you can see roots coming out of the drainage hole at the bottom of the pot.
Step 6: Growing on
When you spot roots, it’s time to separate the plants and put them into their own pots to grow on. First water the cuttings and then tap the cuttings and compost out. Gently tease the plants apart with your fingers and plant them up using the same one part perlite to two parts multi-purpose compost. Water them again and let them grow on for at least another month before planting them outside.
Step 7: Hardening Off
Remember to always harden plants off before moving them from an indoor to an outdoor location. Otherwise you could shock their systems and they can be permanently affected. Plants that don’t get hardened off can die, not grow, or just fail to thrive.
You harden plants off by setting them out on warm sunny days and bringing them back in at night. After a week of this they should be ready to be planted outdoors.
Step 8: Caring for Rosemary
Rosemary is a very hardy plant that requires very little to thrive. They’ll grow in large pots and containers as well as the ground and can eventually become as large as small trees in the right conditions.
Rosemary loves sunshine and needs at least six hours of it per day. It also likes sandy, well-drained soil so dig some into the ground if your soil is naturally more clay. It doesn’t really require any fertlizer or extra nutrients but saying that, I top dress mine with composted manure in the spring if I remember.
If you have freezing cold winters take note that rosemary might not survive outdoors. Planting into pots that can be taken into a sheltered place like a greenhouse or polytunnel will be your best way of keeping them alive over the winter.