Should I paint pruning cuts?
Updated: October 2026
You have heard both instructions in the same month: paint every cut, and never paint a cut. Should I paint pruning cuts has a narrower answer. Leave a clean ordinary cut open. Paint only when a named fresh-wound risk is already on that plant, do it promptly, and do not expect the film to cure anything. Product names appear here only where the Royal Horticultural Society uses them. The tins are on the [tree wax comparison](/hub/trees-and-palms/tree-wax). The Products Compared editorial team wrote this on 16 October 2026 from RHS pages, the Arboricultural Association pruning guide, and a buyer-facing summary of BS 3998:2010. We did not paste the standard, and we did not run a disease trial. A qualifying amazon.co.uk purchase can earn a commission at no extra cost to you.
You have heard both instructions in the same month: paint every cut, and never paint a cut. Should I paint pruning cuts has a narrower answer. Leave a clean ordinary cut open.
You have heard both instructions in the same month: paint every cut, and never paint a cut. Should I paint pruning cuts has a narrower answer. Leave a clean ordinary cut open. Paint only when a named fresh-wound risk is already on that plant, do it promptly, and do not expect the film to cure anything. Product names appear here only where the Royal Horticultural Society uses them. The tins are on the tree wax comparison. The Products Compared editorial team wrote this on 16 October 2026 from RHS pages, the Arboricultural Association pruning guide, and a buyer-facing summary of BS 3998:2010. We did not paste the standard, and we did not run a disease trial. A qualifying amazon.co.uk purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Type | Stated fill | Listed use | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Kiyonal Kiyonal cut paste, 100 g | Bonsai cut paste | 100 g tube | Bonsai tree wounds | 8.4 | about £11.99 | View offer |
 Provanto Provanto Arbrex, 300 g | Pruning seal | 300 g in the title | Pruning cuts on all types of trees | 9.2 | about £7.80 | View offer | |
| Preis-Tipp |  Vividye Vividye sealer, 500 g | Wound paste | 500 g | Pruning, grafting, bark repair, fruit trees | 7.6 | about £10.99 | View offer |
On this page
What a cut does without paint
A pruning cut is a wound the tree already knows how to wall off. Just outside the branch, the collar is a slightly swollen ring. Cut to that collar, not flush to the trunk, and the tree compartmentalises the wood behind it and grows callus over the face. That roll of new tissue is bark in the making. A pot of wax is not a substitute for it. The film you brush on is a coating. It can keep some moisture and some spores off the surface for a while. It does not become bark, and it does not reach an infection that is already inside. The Arboricultural Association puts the risk the other way: paint can slow compartmentalisation, hold damp against the wood, and give canker a sheltered spot. Picture a clean apple cut the diameter of a £2 coin, made with sharp bypass secateurs on a dry day, collar left intact. Within a season the rim should begin to roll in. Nothing in the RHS pruning guidance asks you to cover that face. If the saw tore the collar, the repair is a cleaner cut next time, not a thicker seal. If you are in the exception below, the thin coat is on how to apply tree wound sealer.
Leave it open
For ordinary pruning, leave the cut open. That includes the apple, the rose, a hedge trim that nicked a stem, and the routine shortening of a healthy branch with no disease history. The Arboricultural Association tells you to avoid wound paint, to leave the collar, and to use bypass secateurs so the cut is not crushed. Paint does not tidy a crush from anvil blades. A seal laid on out of habit can inhibit the walling-off the tree was doing. It can trap moisture on a cut that would have dried. It can keep a surface damp for canker. None of those is a reason to buy a tin after a winter tidy-up. If the advice you were given was simply always paint, it is the older habit. Current RHS and arboricultural guidance for home gardeners has moved off it for routine work. A shop label that says the gel suits all types of trees is a sales line about coverage, not a rule that every wound must be coated. Once you know you are not painting, buy nothing. The tree wax buying guide spells that out before any price band.
The narrow case for a seal
There is a short list, and it is not large cuts or winter. On silver leaf, the Royal Horticultural Society says summer pruning is the first defence, because the spores are less active then. Where silver leaf keeps returning, painting a fresh wound might be the lesser harm. The plants they name are laburnum, poplar, Prunus (plums, cherries, and their relatives), and rhododendron. The paints they name are Growing Success Prune and Seal, Provanto Arbrex Seal and Heal, and Vitax Medo. Only Arbrex is in this comparison set. The RHS fungicide note still gives a natural-resin sealer no curative action. You are covering a fresh face, not treating a silvered crown. Bacterial canker is the other timed case. RHS advice is to prune susceptible Prunus in July or August and to paint the fresh cuts promptly, and not to use an amateur spray as if that replaced the timing. Promptly means the new wound, not a scar from last year. A buyer-facing summary of BS 3998:2010 makes the same point without quoting the standard: a sealant is considered soon after wounding, and only where the risk of a fresh-wound pathogen is high. If you are in that case, use a thin coat, not a plug, because a thick layer cracks.
Bleeding sap is not a paint job
Maples, birches, walnuts, and vines can drip after a cut. The Royal Horticultural Society's bleeding page says not to bind the wound and not to paint it. Painting does not stop the sap. The drip is usually spring pressure, not a disease. Prune those bleeders when pressure is lower, instead of sealing a mistimed cut. Do not heat the wound. Some Arbrex retail pages mention a blow lamp on bleeders before the gel goes on. That conflicts with the RHS line, and the Arbrex safety data sheet classes the product as flammable because of ethanol. A flame is the wrong answer to sap. If the crown is silvered, a limb is hanging, or the trunk is split, call an arborist.
Common questions
Should I paint a normal apple cut?
No. A clean apple cut with the collar left in place should stay open so callus can form. Routine wound paint is what the Arboricultural Association tells you to avoid, because it can slow compartmentalisation and trap moisture. The size of the cut does not by itself create an exception. If the apple has no fresh-wound disease you can name, leave the wood bare. A tin that says it suits all trees is describing the gel, not a requirement for that apple.
What about a plum or cherry?
Prunus is where the exception is real. The Royal Horticultural Society flags plums and cherries, and for silver leaf it lists Prunus among plants where a seal on a fresh cut might be the lesser harm if the problem keeps returning. Summer pruning is still the first step. For bacterial canker, the timing is July or August, with paint on the new cuts promptly. A winter cut painted the next weekend is late. The film still does not cure a tree that is already silvered.
Will paint stop a bleeding acer or birch?
No. The Royal Horticultural Society says not to bind or paint bleeding cuts on maples, birches, walnuts, and vines. Sap flow is seasonal pressure. Paint does not switch it off, and a blow lamp next to a flammable gel is not a workaround. Prune those species in the window the RHS bleeding page describes and leave the cut open. An acer in a pot is the same biology. Bonsai paste does not turn a bleeding garden cut into a paint job.
Does Arbrex cure silver leaf?
No. Provanto Arbrex Seal and Heal is one of three products the Royal Horticultural Society names when a fresh-wound seal might be the lesser harm on plants that keep getting silver leaf. The same society's fungicide note does not give a natural-resin sealer curative action. If the leaves are already silver, the fungus is inside the wood. Painting the next fresh cut is a precaution on that new face, not a treatment for the crown.
When is bacterial canker different?
Bacterial canker on susceptible Prunus is one of the few cases where RHS advice says to paint promptly, and to prune in July or August rather than in the dormant season. The paint goes on the fresh cut. It is not a spray programme. A canker wound from last year is not fresh. If the infection is already through the crown, ask someone who can see the tree rather than coating every stub.
Is a thick coat safer than a thin one?
No. A thick pad cracks and peels, which UK reviews of pruning gels describe, and it leaves the wood exposed after you thought it was covered. It also holds more moisture against the cut. Where a seal is justified, the retailer sequence for Arbrex is a thin coat, then a second thin coat only after the first has dried. Thicker is not more protective.
When do I stop and call an arborist?
Call someone when the trunk is split, a limb is hanging, the work needs a chainsaw or a climb, or disease is already through the crown rather than limited to one fresh cut you can reach from the ground. Silver leaf in the foliage, or canker that has girdled a branch, is no longer a paint decision. If you are unsure whether the tree is safe to stand under, that question comes before any tin.
Related pages
Sources
Public UK sources from the research digest, last checked on 16 October 2026. Shelf prices and star lines are the amazon.co.uk figures in the display file. A listed frost line or a seller claim about disease is not a test run for this page.
- RHS: Reducing the size of a tree or shrub safely (retrieved 16 October 2026)
- RHS: Bleeding from pruning cuts (retrieved 16 October 2026)
- RHS: Silver leaf (retrieved 16 October 2026)
- RHS: Fungicides for home gardeners (retrieved 16 October 2026)
- RHS: Bacterial canker (retrieved 16 October 2026)
- Arboricultural Association: A guide to pruning (retrieved 16 October 2026)
- HSE: FAQ on pesticide product information (retrieved 16 October 2026)
- treeterms.co.uk: Wound sealant and BS 3998:2010 (retrieved 16 October 2026)