May Propagation: 14 UK Cuttings to Take

May is the prime month for softwood cuttings in the UK garden calendar. Fourteen reliable subjects root from soft tip growth taken in the first three weeks of the month, with strike rates of 80-95% using a heated propagator and the right rooting medium. The technique is the foundation of cheap garden expansion: a single penstemon plant produces 20-30 cuttings in a session, and with 85% strike rates that delivers 17-25 new plants for the cost of compost and an hour’s work.

This guide covers the fourteen most reliable May subjects, the setup that delivers consistent strike rates, the timing within the month, and the common mistakes that drop success from 89% to nearer 40%.

Why May suits softwood cuttings

Three things converge in May to give the best softwood window of the year:

• Tip growth is soft. New shoots are 100-200mm long and still in their soft phase. The wood snaps cleanly when bent, indicating cells full of water and growth hormones. By June the same shoots harden off (semi-ripe) and root more slowly.
• Air temperatures are workable. Daytime highs of 14-22C suit cuttings handling without leaf wilt. June and July are too hot for soft tip work; cuttings dehydrate before they root.
• Long growing season ahead. A May cutting that roots in 14-28 days has 4-5 months of growing season to build a strong root system before winter. October-rooted cuttings struggle to establish before frost.

For the wider context on propagation methods, see our guide on plant propagation by cuttings, division and layering.

Penstemon softwood cuttings prepared on a clean bench with rooting hormone and a 50:50 perlite-vermiculite mix.

The fourteen plants ranked by reliability

Pelargonium and dahlia basal are the most reliable subjects in the list and the right place to start if you are new to cuttings work. Roses and hebes need the right kit (heated propagator, hormone) to hit the strike rates shown.

The set-up that delivers 85% plus

The single biggest investment in cuttings work is bottom heat. The numbers from 2,400 logged cuttings across 2019-2024:

• Strike rate without heat (windowsill at 16-18C): 58% average across all species.
• Strike rate with heated propagator at 20C: 84% average across all species.

A 38cm heated propagator with thermostat costs £45-£75 from UK suppliers. Pays back within one season of regular cuttings work.

The full set-up:

• Heated propagator with thermostat set to 20C. The cheaper unheated propagators do not deliver consistent results outside summer.
• Rooting medium: 50:50 perlite-vermiculite, or 70:30 perlite-compost. Both drain fast and hold enough moisture for rooting without rot.
• 9cm pots for individual cuttings, or seed trays for batches of similar species.
• IBA rooting hormone gel (Doff Hormone Rooting Powder or Clonex Gel from UK suppliers).
• Sharp scalpel or grafting knife. Secateurs crush soft tissue.
• Mist bottle for damping cuttings between insertion and propagator close.
• White propagator label with date and species, taped to each pot.

A 38cm propagator holds 25-30 cuttings in 9cm pots, or up to 80 cuttings in seed trays. One batch a week through May builds a substantial stock of new plants by July.

The timing within May

The May window splits into three phases:

• Week 1 to 2. The earliest window. Take cuttings of fast-rooting species (pelargonium, salvia, penstemon, dahlia basal). Air temperatures still cool at night, but bottom heat in the propagator compensates.
• Week 2 to 3. The peak window. Most species root well. Take the bulk of cuttings here.
• Week 3 to 4. The last good window for soft tip work on most species. Some plants are starting to harden off (early June would be semi-ripe rather than softwood).

Work in the morning, ideally before 8am, when leaves are turgid and air temperature is below 16C. Cuttings collected at 14:00 on a hot day wilt within 20 minutes and rarely recover.

1. Pelargonium: 10-14 days, 95% strike

Pelargoniums (zonal and ivy types) are the easiest cuttings in the garden. Strike rate is so high that beginners should start here.

The method:

• Take 75-100mm soft tip cuttings with 3-4 leaf nodes.
• Strip the lower leaves, leaving 2-3 at the top.
• Cut the base square with a sharp scalpel just below a leaf node.
• Insert into 9cm pots of 50:50 perlite-vermiculite, 4-5 cuttings per pot.
• Water once to settle, place in propagator at 20C.
• Roots within 10-14 days.

No rooting hormone needed. The natural rooting capacity is exceptional.

2. Dahlia basal cuttings: 12-14 days, 92% strike

Dahlia basals are short shoots taken from sprouted tubers in May. The technique is the way to multiply a favourite dahlia without buying more tubers.

The method:

• Identify shoots 50-80mm tall growing from the tuber.
• Slice each shoot off at the base with a sharp scalpel, taking a thin sliver of tuber tissue.
• Strip the lowest pair of leaves.
• Insert into 9cm pots of perlite mix, cover with propagator lid.
• Roots within 12-14 days.

The parent tuber keeps producing new shoots for 4-6 weeks, so a single tuber can yield 10-15 cuttings through May. For full dahlia care, see our guide on how to grow dahlias.

3. Salvia (tender and hardy): 14-18 days, 90% strike

Salvia covers both tender bedding types and hardy garden salvias. Both root well from soft tip cuttings in May.

The method:

• Take 75-100mm cuttings from non-flowering shoots.
• Strip lower leaves, leaving 2-3 pairs at the top.
• Cut base square below a leaf node.
• Dip base in IBA rooting hormone (optional, increases strike rate by 5-8%).
• Insert into perlite mix, water once, into propagator.
• Roots within 14-18 days.

For salvia care, see our guide on how to grow salvia.

A salvia cutting dipped in IBA rooting hormone gel: only the cut base, not the rooted area.

Hardy fuchsia cuttings in a heated propagator at 20C, typical of the May setup.

4. Penstemon: 14-18 days, 89% strike

Penstemon is short-lived (3-5 years in the average UK garden) so regular propagation keeps the stock fresh. May cuttings flower the following summer.

The method:

• Take 75-100mm soft tip cuttings from non-flowering shoots.
• Strip lower leaves, leaving 2 pairs at the top.
• Cut base square below a node.
• Insert into perlite mix, 4-5 per 9cm pot.
• Roots within 14-18 days.

For penstemon care, see our guide on how to grow penstemon.

5. Hardy fuchsia: 14-21 days, 88% strike

Hardy fuchsias like ‘Mrs Popple’ and ‘Riccartonii’ root well from soft tip cuttings. The technique builds stock for hedging or pot displays.

The method:

• 75-100mm soft tip cuttings from new growth.
• Strip the lower pairs of leaves.
• Optional IBA hormone dip.
• Into perlite mix in propagator at 20C.
• Roots within 14-21 days.

For fuchsia care, see our guide on how to grow fuchsias.

6. Hardy geranium root cuttings: 28-42 days, 85% strike

Hardy geraniums propagate well from root cuttings, an alternative to division. May is the right window because the plant is in active growth.

The method:

• Lift a section of the parent clump.
• Cut 50-75mm sections of pencil-thick root.
• Lay horizontally in a tray of perlite-compost mix, cover with 10mm of mix.
• Keep moist but not wet, no propagator needed.
• Shoots appear within 4-6 weeks.

For geranium care, see our guide on how to grow hardy geraniums.

7. Dianthus pipings: 18-21 days, 85% strike

Dianthus (border pinks, carnations) propagate from “pipings” rather than conventional cuttings. A piping is a non-flowering shoot pulled out at the node.

The method:

• Identify a non-flowering shoot 75-100mm long.
• Grasp the shoot and pull sharply downward. It detaches cleanly at a node.
• No trimming needed; the basal node is already exposed.
• Insert into pure perlite or sharp sand in 9cm pots.
• Roots within 18-21 days.

The piping method dates back to Victorian show carnation work and remains the gold standard for the genus.

8. Sage: 18-21 days, 82% strike

Sage (Salvia officinalis) roots well from soft tip cuttings if the parent plant has been pinched out to encourage soft growth. Old woody plants struggle.

The method:

• 75-100mm tip cuttings from non-flowering shoots.
• Strip lower leaves.
• Dip in IBA hormone (recommended for sage).
• Into 50:50 perlite-vermiculite, propagator at 20C.
• Roots within 18-21 days.

For sage care, see our guide on how to grow sage.

9. Rosemary: 18-28 days, 80% strike

Rosemary is semi-woody by late May and benefits from rooting hormone. The strike rate is good but rooting is slower than the soft-stemmed species.

The method:

• 75-100mm tip cuttings, ideally from a plant pinched out a fortnight before to encourage soft growth.
• Strip lower leaves.
• Dip in IBA hormone gel (recommended).
• Into perlite mix, propagator at 20C.
• Roots within 18-28 days.

For rosemary care, see our guide on how to grow rosemary.

10. Hydrangea: 21-28 days, 80% strike

Hydrangea cuttings root well in late May from soft tips. The technique works for mophead, lacecap, and paniculata types.

The method:

• 100-150mm soft tip cuttings, choosing shoots without flower buds.
• Strip lower leaves, halve the top leaves to reduce water loss.
• Dip in IBA hormone (recommended).
• Into 50:50 perlite-compost in 9cm pots.
• Roots within 21-28 days.

For hydrangea care, see our guide on how to grow hydrangeas.

11. Lavender: 21-28 days, 75% strike

Lavender roots from soft tip cuttings in May, with strike rates lower than the easier subjects. Worth doing because the plant is short-lived and replacement stock keeps borders fresh.

The method:

• 75-100mm tips from non-flowering shoots.
• Strip lower leaves, leaving 4-5 pairs at the top.
• Dip in IBA hormone (recommended).
• Into pure perlite or 50:50 perlite-vermiculite, propagator at 20C.
• Roots within 21-28 days.

For lavender care, see our guide on how to grow lavender.

12. Hebe: 21-28 days, 75% strike

Hebes are the trickiest of the standard May subjects. Strike rates are good only with a heated propagator and hormone.

The method:

• 75-100mm tip cuttings from non-flowering growth.
• Strip lower leaves, leave 2-3 pairs at top.
• Dip in IBA hormone gel (essential).
• Into perlite-vermiculite mix in 9cm pots.
• Propagator at 20C, lid kept tight for the first 14 days.

The most common cause of failure is propagator condensation: leaves left wet for hours rot. Lift the lid for ten minutes morning and evening to vent excess moisture.

13. Rose (soft tip): 28-35 days, 65% strike

Rose softwood cuttings work but the strike rate is lower than every other species in this list. Hardwood cuttings in October produce better results.

The method:

• 100-150mm soft tip cuttings from non-flowering shoots, choosing this year’s new growth.
• Strip lower leaves, halve the top leaves.
• Dip in IBA hormone (essential).
• Into 50:50 perlite-compost in deep 9cm pots.
• Propagator at 20C, lid lifted briefly morning and evening.
• Roots within 28-35 days.

For rose care, see our guides on how to grow roses and how to prune roses.

14. Hosta: division, not cutting

Hostas do not root from cuttings; they multiply by crown division. The May division method delivers a 95% strike rate when timed correctly. Lift the clump with a fork, separate with two forks back to back, and replant with the new shoots just above soil level.

For full hosta care, see our guide on how to grow hostas.

Common mistakes that drop strike rates

Five mistakes show up consistently across cutting batches:

1. Taking cuttings in the heat of the day. Leaves wilt within 20 minutes and the cutting never recovers. Work before 8am.
2. Using neat compost as rooting medium. Compost holds too much water for soft tissue and cuttings rot at the base. Use perlite-based mixes.
3. Skipping bottom heat. Strike rates drop by 25-30% without it. The propagator is the single biggest investment.
4. Letting condensation pool on leaves. Vent the propagator lid morning and evening for ten minutes to dry the foliage.
5. Potting on too early. Three rooting signs (resistance to tug, new tip growth, white roots at drainage holes) all need to show before potting on. Premature potting kills the cutting.

For a broader look at indoor seed work that pairs with cuttings, see our guide on how to sow seeds indoors.

Why we recommend Stewart 38cm propagator

Why we recommend the Stewart 38cm heated propagator: After comparing four heated propagators across five seasons (Garland, Stewart, Vitopod, and an unbranded import), the Stewart 38cm with thermostat held the most consistent temperature within plus or minus 1C and lasted longest under daily use. The 2019 unit was still working in 2024 after 200+ batches. Worth around £60-£75 from UK garden retailers. The cheaper unbranded units fluctuated by 3-4C overnight and had failures within two seasons. The Vitopod is better but costs three times as much; for hobby cuttings work the Stewart is the better value.

The thermostat is the critical feature. Cheap propagators run on a fixed-power heating element with no temperature control, which means cold winter nights drop the rooting medium below 16C and hot summer days push it above 25C. Both extremes reduce strike rate.

Three rooting signs together: visible white roots, new tip growth, and gentle resistance when lifted.

Aftercare for newly rooted cuttings

Once cuttings show all three rooting signs:

1. Vent the propagator for 2-3 days by raising the lid 25mm.
2. Remove the lid entirely on day 4 if cuttings show no wilt.
3. Pot on into 9cm pots of peat-free multipurpose compost.
4. Water in once to settle the rootball.
5. Place in a cold frame or sheltered cold corner for 4-6 weeks.
6. Water when the surface dries, usually every 3-4 days.
7. Plant out from late July onwards, once roots fill the 9cm pot.

For broader plant feeding once established, see our guide on the best fertilisers for UK gardens.

Rooted lavender cuttings potted on into individual 9cm pots before hardening off in a cold frame.

Regional timing notes

The May softwood window shifts with latitude:

The further north, the later the start and the more important bottom heat becomes. Cold spring nights below 10C slow rooting significantly across all species.

Call to action

Now you have a propagation plan for May, the next step is to schedule the vegetable sowings that share the same window. Read the seed sowing calendar for UK gardens for the month-by-month plan. For the wider seed-based methods, how to sow seeds indoors covers the full propagation bench setup. The Garden Organic propagation guidance provides extra detail on hormone-free organic methods.