Inspired by a helpful YouTube guide. We based this walk-through on the popular UK video "Clematis group 1 pruning and care guide", from the Royal Horticultural Society. It walks through group 1 clematis clearly, which is the one most gardeners get wrong because they cut it back too hard.
1. Identify your clematis pruning group first
Clematis are split into three pruning groups based on when they flower and where they form their buds. The group number tells you when to prune and how hard to go.
If you planted it recently, check the label or the nursery's website. For an established plant with no label, note when it flowers. Spring flowering means group 1. Early summer means group 2. Late summer into autumn almost certainly means group 3.
2. Group 1: leave well alone (mostly)
Group 1 clematis flower in late winter and early spring on the previous year's growth. That means cutting back hard will remove all the buds and you will get nothing. Alpina, macropetala, and montana are common group 1 types.
The most you should do is a light tidy after flowering. Remove dead or damaged stems, trim anything that has strayed where you don't want it, and that's about it. These are the ones that can go years without much attention and still put on a good show.
3. Group 2: a light tidy in late winter
Group 2 clematis flower twice: once in late spring on old wood, and again in late summer on new growth. Cut back too hard and you lose the first flush. The aim is a light prune in late February or early March, before growth starts properly.
Remove dead and weak stems. Cut back the remaining stems to a pair of healthy buds. You are thinning rather than chopping. After the first flush of flowers fades, a gentle deadhead and trim encourages a second round later in the season.
4. Group 3: cut hard back in late winter
Group 3 is the one most people are relieved to hear about. These flower on new growth produced each year, so cutting them back hard every late winter is exactly what they need. Viticella, texensis, and most large late-flowering hybrids fall into this group.
In late February, cut every stem back to around 30 cm from the ground, just above a strong pair of buds. It looks brutal. The plant won't mind at all. By late spring it will have put on several feet of new growth and it flowers from midsummer onwards.
5. Clear up the old growth and any dead stems
Once you have pruned, pull out the cut stems from whatever they were growing through. This can take a while with a well-established plant. Be patient and work methodically, rather than trying to yank it all out at once.
Check as you go for any stems that look unhealthy. Signs of clematis wilt include sudden blackening of stems. If you see it, cut back to healthy tissue well below the affected area and bin the clippings rather than composting them.
6. Feed and mulch after pruning
Once the old growth is cleared, give the base of the plant a feed with a balanced granular fertiliser or a handful of slow-release pellets. Clematis are hungry plants and a feed in early spring makes a real difference to the quality of flowering later on.
Add a layer of garden compost or well-rotted manure as a mulch around the base, keeping it clear of the stems. This helps retain moisture through summer, which clematis appreciate. They like their roots cool and their heads in the sun.
7. Train new growth as it comes through
Once new shoots appear, train them in loosely. Clematis tendrils will grip onto whatever is nearby, but left to their own devices the stems tangle badly and become hard to manage. Tying in young growth every few weeks through spring keeps the plant open and well-covered.
Use soft garden twine and tie loosely to allow for stem thickening. Avoid wire or rigid ties that can cut into the stems as the plant grows.
When to call a handyman
If the plant has built up years of tangled old wood and needs a proper sort-out, Richard can help with the clearance. He can also help with tying in plants at height on a wall or pergola where a ladder is needed, and with fitting new wires or trellis for the clematis to grow through.
Need a hand in the garden?
The Sandwich Handyman can help with pruning, garden clearance, fitting trellis and supports, and general maintenance work around the garden in Sandwich and across East Kent.
Contact Richard