Gadenin日本語Get the appLate winter: the one cut that sets the year
This is when the pruning decision is made, and it is the single most consequential thing you do all year. Group 3 plants are cut hard, to about twelve inches (30 cm) above the ground, just above a strong pair of buds. Group 2 plants get a light tidy: dead and weak stems out, remaining stems shortened back to the highest pair of fat, healthy buds. Group 1 plants are not touched at all; their flower buds are already sitting on last year's wood and cutting now removes the entire spring display.
Do this before the buds swell and while you can still see the framework. Once the plant is in leaf you cannot see what you are doing and every cut risks a flowering stem. Work stem by stem rather than shearing, and cut cleanly half an inch (1 cm) above the buds.
This is also the moment to loosen or replace every tie on Group 1 and Group 2 plants, before growth restarts and while the stems are accessible.
| Season | Group 1 | Group 2 | Group 3 |
|---|---|---|---|
| Late winter | Do not prune; check ties | Light prune to fat buds; check ties | Cut all stems to 12 in (30 cm) |
| Early spring | Flowering; mulch and feed | Mulch, feed, protect shoots | Mulch, feed, protect shoots from slugs |
| Late spring | Prune after flowering if needed | First flush opening; tie in growth | Fast growth; fan out and tie in weekly |
| Early summer | Growing wood for next spring | Deadhead first flush; potassium feed | Growth reaching full height; water deeply |
| Midsummer | Water deeply; no feed | Second flush forming on new tips | Main flowering begins; water and deadhead |
| Late summer to autumn | Stop feeding; let wood harden | Second flush; stop feeding before frost | Flowering continues; stop feeding |
| Winter | Leave alone | Leave alone until late winter | Top growth dies back; mark the crown |
Spring: mulch, feed, and guard the new shoots
As the buds break, pull back last year's mulch, scatter a balanced granular feed over the root zone, scratch it in, water it and re-mulch two to three inches (5 to 8 cm) deep. This one round of work carries the plant through the summer better than anything you can do later.
Slug protection matters most now and matters most on Group 3 plants, which are pushing an entire season's growth up from ground level as soft shoots. Losing those shoots in a single night costs weeks. Check after dark, clear debris from around the crown, and stay vigilant until the shoots are a foot (30 cm) tall.
Group 1 plants are in flower during this period. Enjoy them, and if the plant has outgrown its space, prune it in the weeks straight after the flowers fade. That is the only safe window in the entire year for a Group 1 cut, because it leaves the whole growing season for the plant to build the wood that will flower next spring.
Late spring to midsummer: growth, training and water
This is the period of fastest growth and the period when weekly attention pays. Stems can extend several inches a week. Fan them out sideways across their support while they are still soft, four to six inches (10 to 15 cm) apart, and tie loosely. A week missed here is a tangle later.
Watering becomes the main job as temperatures climb. Give an established plant two gallons (about 9 liters) once a week, twice a week in a heatwave, poured slowly at the base. Plants at the foot of a wall and plants in containers need more, and containers may need water twice a day at the peak of summer.
Feed once more with something higher in potassium as flower buds become visible. Deadhead the first flush on Group 2 plants as it goes over; that encourages the second flush that appears on the new tips later in the season. On Group 3 plants deadheading through the flowering period keeps them producing rather than setting seed.
- Weekly: tie in and fan out Ten minutes per plant. Spread new stems sideways, tie loosely with soft twine in a figure of eight, and free anything starting to bunch while it is still pliable.
- Weekly or twice weekly: deep water Two gallons (9 l) slowly at the base of an established plant. Do not sprinkle daily. Check containers every day and water morning and evening in hot weather.
- Once, as buds show: potassium feed Switch from balanced to a higher-potassium feed. Stop nitrogen now, and check that no lawn feed is reaching the root zone.
- Through flowering: deadhead Remove spent flowers on Group 2 and Group 3 plants to push a second flush and prolong the display. Leave seedheads on if you want them for winter interest and accept the shorter flowering.
Late summer to winter: harden off and mark the crowns
Stop feeding around eight weeks before your first expected frost so growth hardens. Keep watering during any late drought, particularly on Group 1 and Group 2 plants, which are forming next year's flower buds on this season's wood right now. A dry late summer is a common and delayed cause of a thin display the following spring.
As autumn closes in, leave the plants standing. Old top growth gives some frost protection to the crown, and there is nothing to gain by cutting early. Clear fallen clematis leaves from under the plants, especially if you had wilt this year, and get them off the site rather than composting them.
Before everything disappears, mark the position of each crown with a cane or a stone. Group 3 plants vanish completely over winter, and a fork or a spade through a dormant crown while you are planting something else nearby is one of the most common ways a healthy clematis is lost.
Write down, every year, the date of the first flower, the date of the last, the date you pruned and how hard, and any week the plant wilted or was checked by drought. Three seasons of that record settles the pruning group beyond doubt and explains almost every poor year before you have to guess at it.