Gadenin日本語Get the appLate winter: look, plan, do not cut
The tree is bare and the structure is visible for the only time all year. This is the moment to walk around it and decide what, if anything, should come out: dead twigs, crossing branches, anything broken by winter weather. Mark those branches with soft ties. Do not cut them now. Sap pressure is rising and any wound made in the next few months will bleed and stay open.
This is, however, the right time for two other jobs. Top up the mulch to two or three inches (5 to 8 cm) over the root area, keeping it off the trunk. And if a potted tree is due, repot it now while it is leafless, either into the next size up or back into the same pot with the outer inch (2.5 cm) of roots trimmed and fresh compost around them.
It is also the only sensible window for moving an established tree that is in the wrong place. Lift with as wide a rootball as you can manage, keep it intact, and replant immediately at the same depth in a sheltered spot with afternoon shade.
Bud break and spring: the frost weeks
The new leaves emerge soft and thin and they are the most vulnerable tissue this tree ever produces. A late frost after bud break turns them limp and brown overnight. Watch the forecast through this period and, on a small tree or a potted one, throw row cover over it or move it against a wall on nights when a clear sky and still air are predicted.
If frost does catch the new growth, leave it. The damage looks final but the tree carries reserve buds and will push a second flush within a few weeks. Cutting the browned shoots off immediately removes live buds you will want; wait until early summer when the dead wood is obvious.
Start watching soil moisture from now on. Spring growth uses a lot of water, and a dry spell during the flush produces leaves that are already stressed before summer starts. Do not feed unless growth has genuinely stalled, and if you do, feed once, at half rate, and no later than early spring.
| Stage | What to watch | Action |
|---|---|---|
| Late winter, fully dormant | Dead and crossing wood, potted trees rootbound | Mark cuts, mulch, repot, move trees |
| Bud break | Frost forecasts, clear still nights | Row cover small and potted trees, do not feed |
| Full leaf, late spring | Soil moisture, aphids on soft tips | Water deeply, hose off aphids |
| Midsummer heat | Leaf margins on the sun-facing side | Deep soaks, check mulch depth, shade potted trees |
| Late summer, growth hardened | Branches you marked in winter | Prune now if at all; take layers or sever last year's |
| Autumn color and leaf fall | Color date, how long leaves hold | Reduce watering, collect seed, mulch |
Summer: the season that is won or lost at the roots
How the tree looks by late summer was decided by how consistently wet its roots were through early and midsummer. Check moisture with a finger under the mulch rather than trusting a schedule, and when you water, soak thoroughly rather than sprinkling. In a hot, breezy week an established tree may want a deep watering twice; in a cool damp week, none.
Potted trees are on an entirely different footing. A maple in full leaf in a pot on a hot day can go from moist to bone dry between morning and evening, and a single missed day shows as brown margins for the rest of the season. Move pots into afternoon shade for the hottest weeks and check them daily.
Watch for the first crisp brown leaf margins and note the date. If they appear across the sun-facing side after a hot dry spell, that is scorch and it is telling you about the position, not about a disease. If instead a single whole branch wilts while everything else stays firm, that is a different and more serious problem and needs cutting out.
Do not feed in summer, and do not prune while the new growth is still soft. Both push exactly the sappy, vulnerable tissue that the season is already punishing.
Late summer: the pruning and layering window
Once the year's growth has hardened and the tree is still in full leaf, the one good pruning window of the year is open. Cut the branches you marked in late winter and nothing else. Wounds made now begin to callus immediately, with weeks of warm active growth ahead of them, and there is no bleeding.
This is also when air layers started in early summer are usually ready to sever, once white roots fill the moss ball, and when a layer that is not yet rooted can simply be left in place until the following spring. Do not sever a layer that has only a few roots visible; it will not survive the transition.
Keep watering through this period. Late summer drought is common and it hits a tree that has just been pruned harder than one that has not.
If the summer has been dry and the ground is hard, postpone pruning to the following year rather than cutting a stressed tree. Nothing on a Japanese maple is urgent enough to justify wounding it during a drought.
Autumn and early winter: wind down
Autumn color is the reward, and how good it is depends on the season the tree has had. A tree that ran short of water in midsummer often drops its leaves early and browns rather than coloring. Note the date the color turns and the date the last leaves fall; over several years those two dates tell you more about the tree's health than anything else you can record.
Collect seed now if you want it, taking the winged pairs when the wings are papery brown but before they are bone dry. Rake up fallen leaves from around the base if the tree has had any dieback, and compost them separately.
Cut watering right back once the leaves are down. A dormant tree uses very little, and saturated winter soil rots the shallow roots. Top up the mulch, check that no ties or stakes are cutting into the bark, and then leave the tree alone until late winter.
The record that makes next year easier
Six dates, kept year after year, cover almost everything: bud break, any late frost damage, the first appearance of brown leaf margins, the date and size of any pruning cut, the start of autumn color, and leaf fall. None of them takes more than a moment to write down.
Together they answer the questions you will actually ask. Is this position too hot, or was it just a bad summer? Is the tree declining, or does it always color late? Should the row cover have gone on a week earlier? Memory is unreliable across twelve months; six dates are not.