When and how to prune Cotinus?

Cotinus is an extremely decorative bush, prized for beauty of its leaf, for its airy flowering and also for ease of cultivation. Hardy, it is also very drought- and heat-tolerant and copes with all soil types, even poor, stony and calcareous. Growing freely, Cotinus eventually forms a bush with an irregular, divergent silhouette. With fairly rapid growth, smokebush can perfectly do without pruning but responds very well to being shaped by gardener’s hand. It is therefore easy to control dimensions and silhouette in order to integrate it harmoniously into a small garden or into a landscaping scheme. Discover in our tutorial all our tips on when and how to prune this very beautiful decorative bush!

When to prune smokebush?

Best time to prune smokebush is between late winter and early spring, when growth has not yet restarted. Flowering occurring on wood aged at least one year, pruning should remain light and spare oldest branches, otherwise risk of losing its light inflorescences.

It is also possible to remove part of branches just after flowering.

How to prune Cotinus?

Pruning Cotinus is within reach of any gardener. Useful to preserve a harmonious habit for your bush, to give it appearance of a small tree or to completely regenerate a specimen, it follows fairly simple principles to apply. In all cases, don’t hesitate to regularly step back from the plant and observe it from different angles to achieve a balanced result.

Maintenance pruning

Left to itself, Cotinus produces numerous branches whose orientation can be random, giving bush a more or less lanky habit. Every year, at start of spring and before new leaves appear, work with a pruning shear or loppers that are well sharpened.

Remove all dead branches at their base.
Cut away parts of branches damaged by frost, cutting back to first bud oriented outwards from the bush.
Cut back to their insertion point branches that grow towards the centre.
If two branches grow in same direction but are very close, keep only the most vigorous.
Similarly, do not let two branches touch and rub against each other, risking wounds to the bark. Select best placed and most attractive one and cut the other.
If you wish, and to reduce bush volume, you can cut back the longest shoots by half (cut just above a node oriented outwards), but bear in mind that flowering only occurs on wood at least one year old, so chances are your bush will not flower on shortened branches. Another option is to let the bush flower and wait until after flowering to cut the concerned branches.

Pruning "into tree form"

Cotinus is a bush that can reach considerable size depending on variety, sometimes resembling a small tree. It is perfectly possible to emphasise this effect by clearing base of trunks while raising the crown.

From the base, select 3 to 5 of the best branches (an odd number often gives a more successful aesthetic). They should ideally spread from the centre in a more or less regular and open way.
Remove cleanly at their base all lateral branches up to desired height to clear main branches which, over time, will thicken and form trunks.
In upper part, proceed as for maintenance pruning and adjust volume to obtain a balanced, rounded whole.
Each year, maintain transparency of trunks and continue maintenance pruning in upper part.

Coppicing and regeneration of Cotinus

To keep a bushy and dense habit for your smokebush, it is entirely possible to force it to totally regenerate each year by coppicing. Coppicing is a very simple operation that consists of cutting all branches close to ground. Cut this way, bush usually produces larger leaves with stronger colours but does not flower.

Using your pruning shear or loppers, cut all shoots to about 15–20 cm above ground, taking care where possible to cut above a bud oriented outwards and so that cut is made on a slant, angled inwards. This prevents water from pooling on the cut.

How to cut a large-diameter branch cleanly?

If branches are of too large a diameter to be cut with a pruning shear or loppers, use a pruning saw.

Start by making a small notch a few millimetres under the branch to be removed.
Then cut from the upper side of the branch and remove the branch a few centimetres above the lower notch. This prevents the branch tearing off a piece of bark if it breaks.
When branch is removed, you can then go back down and cut the remaining stub cleanly.

Tools needed to prune a Cotinus

To prune your smokebush correctly and cleanly, you will need:

pruning shear that is sharp and clean (small branches)
loppers that are sharp and clean as well (medium-diameter branches)
pruning saw (or arborist saw) for large branches
gardening gloves (their protection is not infallible but can still prove useful)