Plumbago roots easily – and it roots best from half-ripened summer growth. A stem taken in July or August, with its lowest pair of leaves removed and kept under a bag in the shade, will have roots in three to four weeks. Below: how to choose the stem, where exactly to cut, and the three methods compared, including rooting in a glass of water.
Plumbago cuttings facts
What to use – new, non-flowering growth Best season – July to August for stem cuttings, late winter for root cuttings Difficulty – easy
Rooting time – 3 to 4 weeks Ready to plant out – the following spring Rooting hormone – helpful, not necessary
Which method should you use?
Three work on plumbago. They do not suit the same moment of the year, nor the same purpose.
Method
When
How long
Best for
Semi-ripe stem cuttings
July to August, from growth that has firmed but not hardened
3 to 4 weeks to root
The reliable choice, and the one to start with
Softwood cuttings
May to June, from soft new shoots
2 to 3 weeks, but wilt easily
Speed, if you can keep the humidity up
Root cuttings
Late winter to early spring, before growth restarts
2 to 3 weeks to shoot
An established plant of three years or more that you can lift
In a glass of water
Late spring to summer
2 to 4 weeks
Watching it happen. Roots are fragile – see the section below
Stem cuttings, step by step
This is the method to learn first. The general principles of taking cuttings all apply.
1. Choosing the stem
Take a healthy shoot that is not flowering – new growth of the current year. A flowering stem puts its energy into blooming, not rooting.
The ideal stem is half-ripened: it bends without snapping, and is no longer soft and floppy.
Use clean, sharp secateurs, a blade or scissors. A crushed cut invites the rot that kills cuttings.
Cut a length of 3 to 4 in (8 to 10 cm), keeping two pairs of leaves.
Cut from the mother plant just above a pair of leaves, so the parent stem does not die back.
The right stem: young growth, reddish and supple, with no flower buds. This is the tip you want.
2. Preparing the cutting
Cut again, this time just below the lowest pair of leaves. The base of the cutting must be a node, not a length of bare stem – roots form at the node.
Cut off the bottom pair of leaves to expose that node. Cut them, do not tear them off: a torn scar is an open door to fungus.
Leave the upper leaves in place. They feed the cutting while it roots.
Either soak the base in water for fifteen minutes, or dip it in rooting hormone. Neither is essential; both help.
Left, where to cut: below the lowest node, then remove that pair of leaves. Right, the cutting ready to go in.
3. Setting it in compost
Fill small pots with cutting compost – half potting compost, half sand or perlite.
Make a hole with a pencil rather than pushing the stem in: forcing it damages the base.
Set the cutting so the bare node is buried and the first pair of leaves sits just above the surface.
Firm the compost around the stem with your fingers. Contact between stem and compost matters more than depth.
4. Keeping it alive while it roots
This is where cuttings are lost. Plumbago stems are soft and dry out fast, so the whole art is holding the humidity without cooking the plant.
Bright shade, never direct sun. Outdoors is fine if the shade is constant.
Compost evenly moist, never soggy.
A clear plastic bag over the pot makes the difference. Keep it off the leaves with two sticks.
If condensation runs down the inside, open the bag for a couple of hours. Standing water on the leaves brings rot.
Warmth helps: around 68°F (20°C) at the base is ideal. Too much heat only speeds up evaporation.
5. Growing them on
After three to four weeks, tug a cutting very gently. Resistance means roots.
Pot on into a slightly larger pot with ordinary potting compost.
Keep them frost-free through their first winter – this is not optional, plumbago is tender.
Plant out or pot up finally the following spring, once the frosts have passed.
Rooting plumbago in water
Yes, it works – and it is the easiest way to see what is happening. Take a softwood or semi-ripe cutting prepared exactly as above, strip the lowest leaves, and stand it in a glass so that the bare node is submerged and no leaf touches the water. Change the water every two or three days. Roots appear in two to four weeks.
One caveat, and it matters: water roots are not soil roots. They are thinner, more brittle, and adapted to living submerged. Pot the cutting up as soon as the roots reach 1 in (2 to 3 cm), while they can still adapt, and keep it under a bag for a week afterwards. Left too long in the glass, a cutting often collapses when it finally reaches compost.
Root cuttings, for an established plant
Only worth it on a plant of three years or more, and it means disturbing the roots – so do it in late winter, before growth restarts.
Scrape the soil away from the edge of the root clump.
Find roots ¼ to ½ in (0.5 to 1.5 cm) thick.
Cut them into lengths of 4 to 6 in (10 to 15 cm).
Lay them horizontally under ½ in (1.5 cm) of moist compost, and firm down.
Keep moist but not wet. Shoots appear in two to three weeks.
The method is close to dividing a perennial, and works for the same reason: dormant buds on the root break into growth once separated from the parent.
The result, the following summer: a potted plumbago flowering on the growth it made from a cutting.
Why cuttings fail, and what to do
The cutting wilts within two days – too much air movement or too little humidity. Bag it, and move it out of any draught.
The base turns brown and soft – rot, from compost that is too wet or a blunt cut. Start again with a clean blade and a grittier mix.
Nothing happens after six weeks – the stem was probably too woody, or too soft. Aim for the wood that bends without snapping.
Leaves yellow and drop but the stem stays firm – often normal. The cutting is shedding load while it makes roots. Leave it alone.
Smart tip about plumbago cuttings
Take five, expect three. Plumbago cuttings cost nothing but a stem, and the failures tell you nothing you could have predicted. Filling a whole tray from one shoot is the surest route to the plant you wanted – and to the spares that make good presents.
Frequently Asked Questions
When is the best time to take plumbago cuttings?
July and August, from semi-ripe growth – stems that bend without snapping. Softwood cuttings in May and June root faster but wilt much more easily. Root cuttings are taken at the opposite end of the year, in late winter, before growth restarts.
Can you root plumbago in water?
Yes. Stand a prepared cutting in a glass with the bare node submerged and no leaf touching the water, and change the water every two or three days; roots appear in two to four weeks. Pot it up as soon as the roots reach 1 in (2 to 3 cm) – water roots are brittle and adapt badly if left too long.
How long does it take for plumbago cuttings to root?
Three to four weeks for semi-ripe stem cuttings at around 68°F (20°C), two to three weeks for softwood cuttings and for root cuttings to send up shoots. Allow another two months of growth in a pot, then plant out the following spring.
Do plumbago cuttings need rooting hormone?
No. Plumbago roots readily without it. Hormone powder or gel raises the strike rate a little and speeds things up, but a fifteen-minute soak in plain water before planting works nearly as well.
Where should I keep the cuttings while they root?
In bright shade, never direct sun, at around 68°F (20°C), with a clear plastic bag over the pot held clear of the leaves. Open the bag for a couple of hours if condensation builds up: standing water on the foliage causes rot.
Can I take cuttings from a flowering stem?
Better not. A flowering stem is spending its energy on blooms rather than roots, and strikes far less reliably. Choose a young non-flowering shoot – and if the whole plant is in flower, simply pinch out a few tips two weeks beforehand to force fresh growth.
How many cuttings can I get from one stem?
Two or three. Each pair of leaf nodes can become a plant, so cut the shoot into sections of 3 to 4 in (8 to 10 cm), each keeping two pairs of leaves, rather than using only the tip.
Written by Gaspard Lorthiois | Loves helping out, especially when it comes to growing things. Worked in herbal medicine, runs a farm, and dabbles in tech. Master's degree and engineer.
