Learn how to pollard a Cotinus in spring step by step
Shrubs grown for their foliage in the border need to be coppiced or pollarded - pruned right back - in late winter or early spring. It seems drastic but by cutting all the previous season's growth off and leaving a stump, it encourages the plant to put out lots of long limbs and leafy growth that work brilliantly in mixed planting schemes.
In this video, Tim Stretton, head of gardens at Mounton House in Monmouthshire, UK, shows how to pollard a smoke bush, Cotinus coggygria ‘Royal Purple’, in the border. The reason for this is to keep the overall height in check and not let it grow into a huge shrub, as then it would crowd out everything around it.
Pollarding like this creates long sprays of young juvenile growth with large leaves that are really shiny and glossy giving a nice display in the summertime in this border of dahlias and asters. This process can also be done to other trees you might want for foliage in the border or to control in size, such as paulownia, elder (Sambucus), tree of heaven (Ailanthus ‘Purple Dragon’) or Eucalyptus gunnii.
It’s worth noting that in pruning hard like this you won’t get flowers at the end of summer, as smoke bush produces flowers on the previous year’s growth, so if you want the smoke-like blooms Cotinus is famous for, you will have to leave it grow for two years to see them. This approach is used to create a lovely backdrop of big dark leaves on a shrub in a border or small planting bed.
If the shrub is newly planted it’s best to let it grow and establish for several years before cutting it down quite low in spring to start the pollarding process, and then every year after that you simply cut back to that point, removing all the previous year’s growth, to maintain that height.
If you were to chop it back right to the ground, that would be coppicing, which is what many gardeners do with shrubs for winter interest in their stems, such as dogwood (Cornus) or willow (Salix), and with hazel for harvesting poles to use in the garden for supports and hurdles or fencing.
First Tim removes all the weak spindly growth from last year, cutting them flush to the main trunk. Then he takes all of last year’s strong growth and reduces it right down to one or two buds above where the old wood was last year and where the new stems started growing from the previous spring. You can use loppers and a pruning saw if the branches are thick, or secateurs if small enough.
Watch out for rising sap if you are pollarding shrubs into late March, when you'll see that your cuts may start to bleed. You will have no problems in February but Tim recommends being more careful as it gets later in the season. Cotinus is from the cashew family and many of the members of that family have poisonous sap or irritant sap. If you’re susceptible to any irritant saps, then wear gloves to prune and pollard, just in case.
