Gadenin日本語Get the appThe root area is the real decision
A flowering cherry sends out a wide, shallow, spreading root system that lives mostly in the top eighteen inches (45 cm) of soil and reaches well beyond the edge of the canopy, often to one and a half times the branch spread. There is no deep anchoring taproot doing the work. That single fact decides where the tree can go, because everything you do on the ground above those roots is done to the tree.
So before you look at the sky, look at the ground. The area you are committing is a circle wider than the mature canopy, and for the whole life of the tree it needs to stay soft, unpaved and undug. A cherry planted at the edge of a lawn that later gets a patio, a path, a raised bed or a trench for a cable will react with dieback in the crown two or three seasons afterwards, and nobody connects the two events. Compaction does the same damage more quietly, so the route your wheelbarrow takes is not the spot.
Distance from hard structures is the other constraint. The roots are shallow rather than aggressive, so they are less of a threat to foundations than the reputation suggests, but a tree that will reach twenty five feet (7.5 m) across needs that width without touching a wall, and its surface roots will lift a thin path laid over them. Measure the expected mature spread of the form you have and plant at least half that distance from anything solid.
| Ground condition | Effect on the tree | Verdict |
|---|---|---|
| Open, sunny, freely drained loam, undug border or rough grass | Fast establishment, full flowering | Best |
| Slight slope with sun most of the day | Good drainage, air moves through the canopy | Very good |
| Heavy clay that stays wet in winter | Root rot and slow decline | Plant on a raised mound or choose elsewhere |
| Within reach of a future patio, path or drive | Root loss and crown dieback years later | Avoid |
| Root zone regularly walked, parked on or barrowed over | Compaction, thin growth, early decline | Avoid |
| Shaded for most of the day by buildings or larger trees | Few flowers, drawn open growth, more disease | Avoid |
Sun, shelter and drainage
Flowering cherries want full sun, meaning six hours or more of direct light through the growing season. Flower bud formation happens the summer before you see the display, so a tree in half shade is not simply a tree that flowers a little less; it is a tree that never sets a proper crop of buds in the first place. Shade also keeps the canopy damp, and damp canopies are where the fungal leaf and blossom problems start.
Drainage matters as much as light. These trees will not tolerate soil that stays saturated in winter. If water stands on your ground after heavy rain, or a test hole a foot (30 cm) deep still holds water four hours after a second filling, plant on a low mound raised four to six inches (10 to 15 cm) above the surrounding level and grade soil out to it, rather than digging deeper and creating a sump.
Soil pH is undemanding, anywhere from about 6.0 to 7.5, and cherries cope with mildly chalky ground better than many ornamental trees. What they do not cope with is a windswept, exposed site, where the blossom is stripped in a single gusty day and the thin bark takes damage. A position with some shelter from the prevailing wind buys you a longer display every spring.
Do not enrich the planting hole heavily. Backfill with the soil you dug out, improved only by forking compost into a wide area around the hole beforehand. A rich pocket in poor surroundings keeps roots circling inside it.
If your site fails on drainage or on space, a cherry is the wrong tree rather than a challenge to solve. These are trees that repay a generous open position and punish a cramped or wet one with a short, disappointing life.
Getting a bare root or containerised tree into the ground
Plant while the tree is dormant and leafless, from leaf fall through to just before the buds swell. Bare root stock in particular must go in during dormancy. Containerised trees can technically be planted at any time, but a dormant planting establishes with far less watering and far less risk.
- Find the graft union first Look for the swollen, slightly kinked joint low on the trunk. Almost every ornamental cherry is grafted onto a rootstock, and that union must finish above soil level. Bury it and the top variety roots into the ground, losing the size control the rootstock provides and inviting rot at the joint.
- Dig wide and no deeper than the roots Make the hole two to three times as wide as the rootball and exactly as deep. Fork the base and sides loose if the spade has glazed them. Width is what lets a spreading root system get away; extra depth only lets the tree settle too low.
- Soak and open the roots Stand a container tree in water until the bubbles stop, then tease the outer roots straight and cut through any that circle the pot. Bare root trees should be soaked for an hour or two before planting and their roots spread out over a low cone of soil in the hole.
- Set the depth by the flare, not the pot The point where the trunk widens into the roots sits level with the surrounding soil. Lay a cane across the hole to check. Cherries planted two inches (5 cm) too deep are a common cause of trees that never quite thrive and slowly die back over five years.
- Backfill, firm gently and water in Return the native soil in layers, firming with your hands rather than treading it hard. Then water with two or three full cans, poured slowly so it soaks in and settles the soil around the roots rather than running off across the surface.
- Stake low and remove the stake early Use a single short stake driven in at an angle, clear of the rootball, with one tie no more than a third of the way up the trunk. A low tie lets the stem flex and thicken. Remove the stake and tie after one or at most two growing seasons; a forgotten tie girdles the trunk.
- Mulch wide and keep it off the trunk Spread two to three inches (5 to 8 cm) of composted bark over a circle at least three feet (90 cm) across, leaving a gap around the bark. Keep grass out of that circle for the first three years.
The first two years, and the suckers that will appear
Water thoroughly once or twice a week through the first two growing seasons whenever the weather is warm and dry, giving enough each time to wet the whole root zone rather than sprinkling daily. After that an established cherry in open ground rarely needs watering except in a long drought.
Do not feed at planting and do not feed in the first year. New roots grow toward moisture, not fertilizer, and nitrogen at this stage produces soft shoots that are exactly what aphids and canker want. The mulch supplies what the tree needs.
Because the tree is grafted, shoots will sooner or later appear from the rootstock, below the union or out of the ground nearby, and they will overtake the tree if left. Pull them rather than cutting: grip the sucker low and tear it downward so it comes away with the dormant buds at its base. A clean cut leaves those buds and three shoots return. Expect the first year or two to be quiet, as a newly planted cherry flowers sparsely while it builds roots.
Record the planting so you can read the tree later
Write down the planting date, the exact position, the form and expected mature spread, and how high the graft union sits above the soil. That last measurement is the one people never take and later wish they had, because it is how you tell settling from correct planting when the tree looks low three years on.
Add a note of what surrounds the root area on the day you plant: where the lawn edge runs, where paths are, what is planned nearby. When crown dieback appears in five years' time, the first question worth asking is what happened over those roots, and only a written record answers it. Then log the first spring the tree flowers properly, and the canopy spread measured each winter.