Gardeners can expand their collection of salvia plants this autumn without spending a penny by taking cuttings. Salvias remain in full bloom with electric blue and deep purple flowers during September, but a hard frost can kill the tender varieties overnight. Taking cuttings now ensures a windowsill full of young plants by spring while avoiding the cost of new purchases.
Timing and tools for autumn propagation
Timing matters, though. It’s advisable to take salvia cuttings in August or September, while growth is still soft or just beginning to harden. That makes these last days of September and the first week of October your final window before temperatures drop — make haste! Sharp tools are necessary to make a clean cut, which helps the cutting root rather than rot. The source recommends Niwaki garden snips for their value and portability.
These snips are small enough to fit in a pocket, making them ideal for gardeners who need quick access to clean, precise cuts. A rooting hormone gel stimulates root production and protects the cut end from bacteria. Clonex Growth Technology 50ml Rooting Hormone is a specialized product typically containing plant growth hormones and a fungicide, which work together to enhance rooting success while shielding the cutting from pathogenic organisms.
Rooting hormone works best when the cuttings are inserted into gritty compost. Melcourt SylvaGrow Seed Compost offers a 100% peat-free option, though adding horticultural grit improves drainage for coarser stems. For particularly thick or woody cuttings, Melcourt recommends mixing in up to 50% grit to ensure proper aeration and moisture balance. A propagator or clear plastic bag creates a humid environment for the cuttings. This setup is simple enough for beginners, requiring no special skills or a greenhouse.
Selecting and preparing healthy cuttings
Go out in the morning, when the plant is at its most hydrated. Using sharp snips or secateurs, cut several stems from shoots that aren’t flowering, and put them straight into a plastic bag so they don’t wilt. Water the parent plant well the day before if it’s been dry. Try to select healthy, vigorous shoots with no flower buds. A cutting trying to flower has no energy left for making roots.
Each cutting is trimmed to a length of 5–8cm (2–3 inches), then the bottom half of the leaves is carefully pinched or cut off to minimize moisture loss. If the remaining leaves are large, cutting them in half across their broad surfaces further reduces transpiration while the cutting lacks roots to replace lost water. Dip the base into rooting hormone, then insert your cuttings around the edge of your pot of gritty cuttings compost (I’d use around five or six cuttings for a 15cm pot). Make a hole with a pencil or dibber first so the hormone isn’t rubbed off.
Rooting and overwintering the new plants
Water them in, then place the pot in a propagator or cover it with a clear plastic bag. You can keep the bag off the leaves with a couple of sticks. Keep the pot at room temperature until the cuttings have rooted, out of direct sun. A bright windowsill away from a radiator is ideal. Air the bag or open the propagator vents every few days to stop mould building up. Salvias usually root within three to four weeks. You’ll know they’ve taken when you see fresh new growth or roots poking out of the drainage holes.
Once rooted, pot each cutting into its own 8 to 9cm pot and overwinter in a frost-free place, such as a cool greenhouse, porch or windowsill. Water sparingly over winter, just enough to stop the compost drying out completely. In spring, pinch out the tips to make bushy plants, then harden them off and plant out once the risk of frost has passed.