How to Propagate Sage: Cuttings, Layering and Replacing an Old Plant

Plan to replace every three or four years

A sage plant is at its best in years two and three. By the third or fourth summer the base is bare wood, the stems have lengthened and started to lean, and the middle of the plant opens out into a ring with a hole in it. No amount of pruning fixes this, because sage rarely produces new shoots from old leafless wood, so the fix is always a new plant.

That makes propagation part of the routine rather than an occasional project. Take a few cuttings every second summer and you always have a young plant coming on, and you can pull the old one out the moment it starts to sprawl instead of putting up with it for another year.

Cuttings and layering give you an exact copy of the parent. Seed does not, so if you have a plant that has proved hardy and productive in your garden, propagate it vegetatively.

Taking cuttings

Sage roots readily and needs no special equipment. The main errors are taking material that is too old, leaving too many leaves on, and keeping the cuttings too wet. Choose non-flowering shoots: a shoot with a flower bud in it puts its energy into the flower and roots poorly or not at all.

1. Cut four inch shoots in the morning Take three to four inch (8 to 10 cm) non-flowering shoot tips early in the day while they are full of water. Put them straight into a bag out of the sun; a wilted cutting has lost half its chances before you get to the bench.
2. Trim below a leaf joint and strip the lower leaves Cut cleanly just below a joint and pull off the leaves from the bottom half. Leave two or three pairs at the top. Any leaf that would sit in or on the compost will rot and take the cutting with it.
3. Insert into a gritty mix around the edge of a pot Use half potting mix and half sharp sand or perlite. Push each cutting in an inch deep around the rim of a pot, five or six to a five inch (13 cm) pot, and firm gently. Rooting hormone helps a little with semi-ripe material and is not needed for softwood.
4. Bright shade, and only just damp Keep them out of direct sun at around 65 to 70F (18 to 21C). Sage cuttings rot under a sealed propagator lid, so if you use one, leave the vents open, and water only when the surface dries. Wilting for the first two days is normal.
5. Test by tugging after three weeks Give a cutting the gentlest tug. Resistance means roots. Softwood cuttings usually root in two to three weeks, semi-ripe in four to six. Once rooted, pot each one on into its own three and a half inch (9 cm) pot.

Cuttings also root in a glass of water on a windowsill, but water roots are brittle and adapt badly to soil. If you use water, pot them up as soon as the roots are half an inch long.

Mound layering renews a plant where it stands

Mound layering is the traditional answer to an old sage and it is easier than cuttings. In spring, heap free-draining soil or a gritty potting mix into the center of the plant, burying the lower few inches of the bare stems and leaving the leafy tips clear. Buried sage stems root along their length over the summer.

By autumn, or the following spring, scrape the mound away and you will find roots on several stems. Cut each rooted stem away below its roots and you have three or four new plants from a single old one, all at once, without ever having lost your supply of leaves.

1. Mound in spring as growth starts Work a mix of soil and grit down between the stems until three or four inches (8 to 10 cm) of each bare stem is covered. Keep the mound off the very center of the crown so water does not sit there.
2. Keep the mound just moist through summer Roots will not form in a mound that bakes dry. Water it in dry spells, but never let it turn into wet mud, which rots the stems instead of rooting them.
3. Lift and separate in autumn or early spring Scrape the soil off and check for white roots on the buried stems. Cut each rooted section off below the roots and pot it up or plant it straight out.
4. Discard the old center Once you have the rooted pieces, dig out and bin the exhausted parent. Leaving it in place gives you the same sprawling plant again next year.

Simple layering for one or two plants

If you only want a plant or two, peg down a single low, flexible stem instead. Bend it to the ground, scrape a shallow inch-deep trench, nick the underside of the stem lightly where it touches the soil, and hold it down with a stone or a wire pin. Cover with gritty soil, leaving four inches of the tip standing clear.

Keep the spot from drying out and leave it alone. By the following spring the buried section will have rooted and you can sever it from the parent and lift it. Sage often does this by itself where a stem falls sideways onto bare soil, and those self-rooted pieces are perfectly good plants.

Growing on and keeping track

Rooted cuttings and layers need the same treatment as seedlings: a free-draining mix, full light, and watering only when the pot feels light. Pinch the tips once to make them branch. Plant out after the last frost, 18 to 24 inches (45 to 60 cm) apart, into unimproved soil, and take only a few leaves in their first season.

Label everything with the date the cutting was taken and which plant it came from. Over a few years this is what tells you which of your plants is actually worth keeping: one parent will consistently produce cuttings that root faster and come through winter better, and without labels you will not know which one it was.

Autumn is the worst time to plant out a young sage. A rooted cutting from late summer is far better kept in its pot somewhere sheltered and dry over winter, then planted out in spring.