Propagating rosemary: cuttings, layering & seeds

Eric
Eric
Eric
Eric

I love plants. I have a BSc. in Turf and Landscape Horticulture, an MSc. in Crop Production, and a Ph.D. in Crop Science, as well as over 20 years of experience in landscaping, gardening, horticulture, and agriculture. The central focus throughout my career, has been on caring for the soil, as healthy soil makes for healthy plants, and plants are integral to the sustainability of life.

Favourite vegetables: basil, garlic, onions and leeks
Favourite fruits: ripe figs, blueberries and dates

Propagating rosemary is easy and a great way to spread this wonderful herb throughout your garden or home.

salvia-rosmarinus-cuttings
Rosemary is easy to propagate with cuttings

Rosemary (Salvia rosmarinus) is a resilient plant that is easy to propagate. Read on for the proper steps to successfully propagate rosemary.

Rosemary propagation: from cuttings or seed?

Rosemary seeds are very sensitive and do not have consistent germination rates. Once sprouted, rosemary seedlings take a long time to grow. Therefore, propagating rosemary by layering and with cuttings is best.

Rosemary cuttings in starter tray
Cuttings are the easiest way to propagate rosemary [Photo: MicrostockStudio/ Shutterstock.com]

How to grow rosemary from cuttings

The best time to take rosemary cuttings is when the plant is actively growing and has not yet started flowering. This is usually in late spring and early summer. The fresh, fast-growing shoots are the easiest to root. Taking cuttings in the morning is best as this is when the plant has the most water in it, and the cuttings will be more resilient to stress. Follow these steps and you will soon have a new plant growing from your rosemary cuttings.

  1. Use a sharp knife to cut off only non-flowering portions of the fresh shoots. Flowering shoots will spend their energy on flower and seed development instead of on rooting.
  2. Take 5 – 10 cm long cuttings and place into an air-tight container.
  3. Remove the leaves from the lower 1 cm of the cutting, dip end in rooting hormone, and place into a free-draining growing medium that is low in nutrients, such as our Plantura Organic Herb & Seedling Compost. With its light and loose soil structure and its low nutrient levels, our peat free compost makes an excellent propagation medium. Stick multiple cuttings into a small pot or use a seed tray with one cutting per cell.
  4. Water and cover with a transparent cloche or tent with a bag; the humidity will reduce water loss while the cuttings are taking root. Ventilate your cuttings daily to prevent a build-up of humidity and stagnant air that can encourage fungal diseases.
  5.  Place near a bright window and mist plants as needed to keep soil moist.
  6. After several weeks, new roots will form. At this point, they are ready to be hardened off. Gradually remove the covering to decrease humidity and slowly introduce them to full direct sunlight.
  7. When they can tolerate the outside environment, they are ready to be planted out in the garden or in larger pots.
Rooted rosemary cutting
When rosemary cuttings have properly taken root, they are ready to be transplanted [Photo: Khrystyna Sun/ Shutterstock.com]

If you have a low and creeping variety of rosemary, try layering to propagate it. This method involves laying a section of stem or branch over the soil in a small pot or just a mound of garden soil. Strip the leaves off the area that is in contact with the soil, then dust this portion of stem with rooting hormone, before pilling more soil on top. Keep the soil moist, and adventitious roots will eventually grow. Once roots have developed, cut this branch off from the parent plant.

Organic Herb & Seedling Compost, 20L
Organic Herb & Seedling Compost, 20L
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(4.8/5)
  • Perfect for herbs as well as sowing, propagating & transplanting
  • For aromatic herbs & healthy seedlings with strong roots
  • Peat-free & organic soil: CO2-saving composition
£12.49

How to grow rosemary from seed

Planting rosemary from seed is a bit tedious, but possible. Sow a few seeds into a very sandy potting mix – a 2:1 mixture of sand and our Plantura Organic Herb & Seedling Compost will do the trick. Then lightly cover with a fine dusting of soil to help keep the seeds from drying out due to exposure. These are tiny seeds, so they do not like to be planted deeply. Water them in, and place in a warm and sunny location. The soil should not completely dry out, so keep an eye on it and mist when needed. The optimal temperature range for germination is 21 to 27 °C. Germination will occur in 2-4 weeks. Once the rosemary seedlings are about 12 cm tall, transplant them into pots or harden them off before planting them directly in your garden.

Now that you know how to propagate rosemary plants, learn how to care for your rosemary plants in our in-depth article on the subject.