Pruning Groups Explained: The Complete UK Guide
A pruning group is a simple label that tells you when, and how hard, to prune a plant so you never accidentally cut off the growth that carries next year’s flowers. The Royal Horticultural Society (RHS) sorts woody shrubs, trees and climbers into numbered groups 1 to 13, with separate systems for clematis (groups 1 to 3), wisteria and roses. Grasses, ferns, palms, bamboos and perennials sit outside the numbered system and are cut back in their own way. This guide explains every group in plain English – and because every outdoor plant we sell is tagged with its pruning group and a plant-specific note, you can go straight from ‘what group is this?’ to knowing exactly when to reach for the secateurs.
Why pruning groups matter
Most flowering shrubs bloom on one of two kinds of wood: growth made last year (often called old wood) or growth made in the current season (new wood). Prune at the wrong moment and you remove this year’s flower buds before they ever open. Pruning groups take the guesswork out of it – match a plant to its group, prune at the right time, and you get the best flowers, a healthy framework and the size you want.
The RHS pruning groups 1 to 13 at a glance
These groups cover deciduous and evergreen shrubs, trees and climbers. Find your plant’s group below, then prune at the time shown.
| Group | What it covers | When to prune | Examples |
|---|---|---|---|
| 1 | Minimal pruning – trees & shrubs with a good natural framework | Winter, or as needed | Acer, Magnolia, Hamamelis, Daphne |
| 2 | Deciduous, flowering on last year’s wood | Straight after flowering | Philadelphus, Deutzia, Weigela, Forsythia |
| 3 | Deciduous, renewing with shoots from the base | After flowering | Kerria, Spiraea ‘Arguta’, Stephanandra |
| 4 | Hydrangeas (mophead, lacecap, aspera) | Early spring, after frosts | Hydrangea macrophylla, H. serrata |
| 5 | Deciduous, winter or early-spring flowering | After flowering | Prunus triloba, Edgeworthia |
| 6 | Deciduous, flowering on new growth | Early to mid spring | Buddleja, hardy Fuchsia, Hibiscus syriacus |
| 7 | Coppice or pollard for winter stems or bold foliage | Late winter to early spring | Cotinus, Sambucus, Eucalyptus, Paulownia, Catalpa |
| 8 | Early-flowering evergreens | Minimal; tidy after flowering | Sarcococca, Mahonia, Acacia, Leptospermum |
| 9 | Late-flowering evergreens | Mid to late spring | Fatsia, Olearia, Callistemon, Griselinia |
| 10 | Grey-leaved & dwarf sub-shrubs | After flowering | Lavandula, Santolina, Brachyglottis |
| 11 | Vigorous climbers | As needed | Trachelospermum, Campsis, Actinidia, climbing Hydrangea |
| 12 | Moderately vigorous climbers | After flowering or in spring | Passiflora, Hardenbergia, Clianthus |
| 13 | Wall-trained shrubs | Annually, after flowering or in spring | Abutilon, Ceanothus, Chaenomeles |
Groups 1 to 7: deciduous shrubs & trees
The lower numbers run from plants that need almost no pruning (Group 1), through those pruned after flowering because they bloom on last year’s wood (Groups 2 to 5), to those cut back hard in spring because they flower on new growth or are grown for their stems and foliage (Groups 6 and 7).
Groups 8 to 10: evergreen shrubs
Evergreens need far less pruning than deciduous shrubs. Early-flowering kinds (Group 8) are simply tidied after flowering; later-flowering evergreens (Group 9) get a light shaping in spring; and grey-leaved sub-shrubs (Group 10) are trimmed lightly, never back into bare old wood, which will not reshoot.
Groups 11 to 13: climbers & wall-trained shrubs
Climbers range from vigorous types that just need keeping in bounds (Group 11) to those trained tightly against a wall and pruned every year (Group 13). Explore our hardy climbers and climbers for walls & fences.
Clematis pruning groups 1, 2 and 3
Clematis have their own three-group system – the single most-asked pruning question in the garden. The trick is knowing when your clematis flowers.
- Group 1 – no routine pruning. Early clematis that flower in spring on last year’s growth, such as C. montana, armandii, alpina, macropetala and cirrhosa. Prune only if they outgrow their space, and then straight after flowering.
- Group 2 – light prune. Large-flowered hybrids that bloom in early summer on last year’s stems (for example ‘Nelly Moser’ and ‘The President’). In February remove dead shoot-ends back to a strong bud, then tidy again after the first flush.
- Group 3 – hard prune. Late clematis that flower from mid-summer on the current season’s growth, including the viticella and tangutica types and ‘Jackmanii’. Cut every stem back hard to a low pair of buds about 20 to 30cm above the ground in February.
Wisteria: summer and winter pruning
Wisteria flowers best on a short spur system, built by pruning twice a year. In summer (July to August), shorten the whippy new shoots to five or six leaves. Then in winter (February), cut those same shoots back further to two or three buds. It sounds fussy, but it is the secret to a wall of spring flower.
Roses: their own groups
Roses sit outside the 1 to 13 system and are pruned by type – bush roses (hybrid tea and floribunda) hard in late winter, shrub and species roses only lightly, and climbers and ramblers after flowering. If you grow roses, prune to the type rather than to a number.
How grasses, ferns, palms and other exotics are handled
The numbered groups are built around woody shrubs. Much of an exotic or architectural garden is cut back differently – and this is exactly where most guides fall silent.
Ornamental grasses
Deciduous grasses (Miscanthus, Pennisetum, pampas) are cut right down to the base in late winter, just before new growth appears; evergreen grasses and sedges (Carex, Festuca, Stipa) are never cut hard – simply comb out the dead blades by hand. Browse ornamental grasses.
Ferns
Remove the old, tired fronds of deciduous ferns in late winter before the new croziers unfurl; evergreen ferns keep their fronds – just take off any tatty ones in spring. See our hardy ferns and tree ferns, whose crowns must never be cut.
Palms
Palms cannot be pruned in the usual sense – they grow from a single crown. Remove only dead lower leaves, never cutting them flush with the trunk or touching the crown. Explore hardy palms.
Bamboo
Bamboo is thinned rather than pruned to a group: in spring, cut weak, dead or spindly canes to the ground and thin congested clumps to show off the best stems. See hardy bamboo.
Hardy succulents & agaves
Rosette succulents are not pruned – simply remove dead or damaged leaves and keep them dry over winter (mind the spine tips on agaves). Browse agave & succulents.
Herbaceous perennials
Perennials die back to a crown each year. Cut spent top-growth down in autumn, or better still leave it for winter structure and cut back in early spring. See hardy perennials.
How to find your plant’s pruning group
- Check the plant label or a reliable reference such as the RHS.
- Note when it flowers and whether that flower comes on last year’s wood or the current season’s growth – this decides the timing.
- If you are unsure, watch the plant for a season before pruning; you rarely lose anything by waiting.
- Shopping with us? Every outdoor plant’s product page shows its pruning group and a note written for that exact plant – so you never have to guess. Start with our hardy exotics range.
Pruning groups: frequently asked questions
What are the RHS pruning groups?
They are a numbering system – groups 1 to 13 for shrubs, trees and climbers, plus separate systems for clematis, wisteria and roses – that tells you when and how hard to prune so you do not cut off next year’s flowers.
How do I know what pruning group my plant is in?
Check the plant label or a trusted reference, and note whether it flowers on old or new wood and when. Every outdoor plant we sell lists its pruning group and a specific note on its product page.
What is the difference between clematis pruning groups 1, 2 and 3?
Group 1 flowers early on old wood and needs little pruning; Group 2 are large-flowered hybrids given a light prune in February; Group 3 flower late on new growth and are cut back hard in February.
What happens if I prune at the wrong time?
You may remove the buds that would have flowered, so you lose a season of bloom. The plant itself is rarely harmed – you simply wait until next year.
When should I prune plants that flower on new wood versus old wood?
Plants that flower on the current season’s growth (new wood) are pruned in late winter or early spring; those that flower on last year’s growth (old wood) are pruned straight after flowering.
Do grasses, ferns and palms have pruning groups?
No. Deciduous grasses are cut to the ground in late winter, evergreen grasses combed through, ferns have their old fronds removed in spring, and palms are never topped – you only take off dead fronds.
When should I prune wisteria?
Twice a year: shorten the new shoots to five or six leaves in summer (July to August), then cut them back to two or three buds in winter (February).
Can I hard-prune a shrub that is not in a hard-prune group?
It is risky. Cutting an evergreen or grey-leaved shrub back into old, bare wood often will not reshoot, so match the plant to its group before you cut.
What pruning group is my hydrangea or buddleia?
Mophead and lacecap hydrangeas are Group 4 (pruned in spring); Buddleja davidii is Group 6 (hard-pruned in early spring). Clematis depends on its type – see the clematis section above.
When is the general best time to prune in the UK?
Late winter to early spring (February to March) suits most plants that flower on new growth, while spring and early-summer flowerers are pruned right after they bloom. Avoid pruning into hard autumn frosts.