Gadenin日本語Get the appThe shape of the year
An apple tree asks very little of you for most of the year and a great deal on about five days of it. Those days are the winter prune, the nights when frost threatens open blossom, the afternoon you thin the fruitlets, and the two or three passes you make picking. Miss the thinning and you lose next year as well as this one; miss the picking window and the crop is either flat or mealy.
The other governing fact is that this summer builds next summer. Fruit buds for the following season form during the current one, from around midsummer, while the tree is still carrying its crop, so everything you do about load, water and feed in early summer is paid out a year later. Tie the seasonal names below to the tree rather than the calendar: bud burst, full bloom, petal fall, the early drop and first color are the events that matter, and they read the same in either hemisphere.
| Season | Main job | The decision |
|---|---|---|
| Dormant winter | Structural pruning, cleanup | How much to remove, and which limbs |
| Late winter | Feed, mulch, check ties and stakes | Whether the tree needs nitrogen at all |
| Bud burst to bloom | Watch for frost and scab weather | Whether to cover the tree overnight |
| Petal fall | Watch for pests; hang traps | When the codling flight has started |
| After the early drop | Thin the fruitlets | One fruit per cluster, how heavily to reduce |
| Midsummer | Water, summer prune vigorous trees | Whether growth needs calming |
| Late summer to autumn | Pick over the tree repeatedly | Which fruit lifts cleanly today |
| Leaf fall | Clear leaves and mummies, plant new trees | Nothing; just do it |
Winter: the only time you shape the tree
With the leaves off, the whole framework is visible and the tree is dormant, so this is when structural work happens. Take out dead, damaged and cankered wood, then crossing branches, then anything growing inwards or straight up, and finally thin what remains so light can reach every part of the canopy. Keep to about a quarter of the canopy at most in any one winter.
Winter is also cleanup. Rake and remove fallen leaves under the tree, since that is where scab overwinters, and pull off any mummified fruit still hanging. Scrub loose bark on the trunk and main limbs to destroy overwintering codling larvae, and remove the cardboard trunk bands you put on in summer.
Check the physical things while you are there: tree ties for tightness, stakes for rot at ground level, and mulch pulled back from the trunk. Then, in late winter before growth starts, feed only if the tree needs it. Judge by last year's extension growth: under about a foot of new shoot on a mature tree means it is hungry, and over two and a half feet means it is already too vigorous and should get nothing.
Spring: bloom is the crop
From bud burst the tree moves quickly, and two things matter: frost and pollination. Open blossom is killed at around 28F (-2C), and a single clear, still night at that temperature during full bloom can remove an entire year's fruit. Watch the forecast through the bloom period, and if a hard frost is coming, cover a small tree overnight with row cover, removing it in the morning so bees can work.
Do not spray anything on or near open blossom. Pollination depends entirely on insects flying, and bees need it above roughly 55F (13C), dry and not windy. In a cold or wet bloom period, hand pollinating the king blooms is worth the hour it takes on a small tree.
Record the date the first flowers open and the date of full bloom, because that number anchors the rest of your year. Hang codling moth pheromone traps before bloom and check them twice a week, and watch new leaves for aphids and for the first olive scab blotches, which follow a warm wet spell by two to three weeks.
The first heavy fruitlet drop, within a couple of weeks of petal fall, is the unpollinated flowers going and is entirely normal. It is not a failure and it is not a reason to feed the tree.
Early summer: thinning is the job that decides two years
After the natural early-summer drop has finished, the tree still holds far more fruit than it can ripen. Thinning now is what gives you large, well-colored apples this year and a crop at all next year, because a tree left overloaded puts everything into seed development and forms no fruit buds for the following season. That is what biennial bearing is, and thinning early is how you break it.
- Wait for the natural drop to finish Thinning before the tree has shed on its own wastes work and can leave you short. Once fruitlets stop falling, usually a few weeks after petal fall, start.
- Reduce each cluster to one Keep the largest, best-shaped fruit in the cluster, normally the central king fruit unless it is misshapen or damaged. Remove the rest with scissors or by pinching the stalk, taking care not to knock off the spur.
- Then space along the branch Go along each branch and thin further so that remaining apples sit four to six inches (10-15 cm) apart. Two apples touching will rot where they meet and will both stay small.
- Take off anything marked, and be harder in a heavy year Remove fruitlets with sawfly scars, scab spots or insect holes first. If the tree cropped lightly last year it will try to overload this year, and thinning severely now is the only way to get a crop the year after.
Thin earlier rather than perfectly. The effect on next year's fruit buds depends on removing the load before the seeds develop, so a rough thinning done promptly beats a careful one done a month late.
Midsummer to harvest
Through the heat, the priority is steady water. Irregular watering, a dry spell followed by a soaking, is what causes split fruit and drives bitter pit. Water deeply and less often, and keep the mulch topped up rather than watering little and often. Established trees only need this in genuine drought; young trees need it every dry week.
This is also when you calm a vigorous tree down. Summer pruning, cutting the current season's side shoots back once their bases have gone woody in late summer, removes leaf area and encourages fruit buds instead of extension growth. It also lets light onto the fruit so it colors. On a restricted form such as a cordon or espalier, summer pruning is the main prune of the year.
Watch for a second codling moth generation in warm areas, keep collecting fallen apples weekly, and prop any branch bending dangerously under a heavy crop rather than letting it split. Then start testing for ripeness ahead of when you expect it: lift and twist a few apples on the sunny outside of the tree, and if they resist, wait three or four days. Pick over the tree several times across two to four weeks rather than stripping it at once.
Autumn: setting up next year
Once the last apples are in, the work is all preventive and it is the highest-value hour of the year. Rake up and remove every fallen leaf under the canopy, because scab spores overwinter in them and will start next spring's infection. Pull down mummified fruit still hanging in the branches, and clear all windfalls off the ground.
Remove and destroy the cardboard trunk bands with their overwintering codling larvae. Renew the mulch over the root area, keeping it clear of the trunk, and check that the tree circle is still free of grass on a young tree.
Leaf fall to bud burst is also the bare-root planting season, so if a pollination partner turned out to be missing this spring, this is when you fix it.
| Symptom this year | Likely cause | What to change next year |
|---|---|---|
| Heavy bloom, no fruit at all | No compatible partner in overlapping bloom | Plant a partner or a crab apple |
| Bloom killed overnight | Frost at or below 28F (-2C) | Cover on frost nights; avoid frost pockets |
| Hundreds of small dull apples | Not thinned | Thin to one per cluster after the early drop |
| Huge crop, then a blank year | Biennial bearing | Thin hard and early in the heavy year |
| Grubs in the cores | Codling moth | Trap early, band trunks, collect drops weekly |
| Cracked brown patches on the fruit | Scab | Clear fallen leaves; open the canopy in winter |
| Masses of upright shoots, little fruit | Over-pruned last winter | Prune far less; tie branches towards horizontal |
Keep a short record each year: the winter pruning date and how much you removed, the full-bloom date, any frost during bloom, the date you thinned and how heavily, and the first and last picking dates. The gap from full bloom to first picking predicts next year's harvest to within a week.