Gadenin日本語Get the appLate winter: the only pruning window
With the leaves off you can see the frame. This is when structural work happens: choosing a single leader on a young tree, raising the lowest branches toward six feet (1.8 m) so you can get a roller underneath, and taking out dead, crossing and inward-growing wood on an older one. Pick a dry, mild spell rather than a wet or frosty one, and disinfect the saw between cuts.
It is also the time to look hard at the bark on every limb you can reach. Sunken orange patches and rough cracked areas are cankers, and cutting them out now, well below the damage, is far easier than doing it in summer when the canopy hides everything.
Finish the window by checking stakes and ties on young trees, loosening anything that has started to bite into the bark, and topping up mulch out toward the drip line while keeping it a couple of inches (5 cm) off the trunk.
Spring: growth, water and the ground under the tree
Buds break relatively late on chestnut. Once they move, stop pruning; from here on the tree is building the shoots that will carry this year's flowers. Feed only if growth has been genuinely poor, and use something that does not raise soil pH; chestnut on the right ground rarely needs feeding at all.
Keep a three-foot (90 cm) circle clear of grass around young trees and water them through any dry spell, ten gallons (38 L) at a time rather than a daily splash. Mature trees look after themselves in a normal spring but a drought now shows up as shed burrs in midsummer.
This is the practical moment to sort out the ground you will be harvesting from. Level any ruts, clear brambles and leaf litter out to the full canopy spread, and get grass under the tree into a state where it can be mown short later. Doing it now is easy; doing it in autumn with nuts already falling is not.
Summer: flowering and the crop set
In early to midsummer the tree hangs with cream catkins and the whole garden smells of them. This is the week that decides the crop. Note when each tree first sheds pollen and when the small green female clusters at the catkin bases look receptive, because on a wind-pollinated pair the overlap between those two is the entire mechanism.
Through the rest of summer, water in prolonged dry weather. Burrs shed in quantity in midsummer with undersized contents is drought talking, and once they are on the ground they are not coming back. Watch the canopy for a single limb going brown while the rest is green, which is the classic first sign of blight.
Late summer is when the adult weevils are drilling into the developing nuts. There is nothing to do about it at that moment, but it is worth knowing it is happening, because it explains why last year's sanitation matters more than anything you can do now.
Autumn: the four weeks that matter
Mow the ground under the canopy short before the first burrs split, and have the roller, buckets and boots ready. The drop runs over three to five weeks with a heavy peak in the middle, and the discipline is simple and absolute: gather every day, twice a day in warm or wet weather. Nuts left for 48 hours mold, get tunneled, or are taken by squirrels and deer.
Float-test every day's batch as it comes in, discard the floaters, and cure the sinkers one layer deep in a cool airy shade at around 60F (16C) for seven to ten days before bagging them in perforated plastic in the refrigerator at 32-36F (0-2C). Chestnuts are perishable; they do not sit in a sack in the shed the way a walnut does.
When the drop finishes, do the cleanup that sets up next year. Rake up and destroy every remaining nut, split burr and cull, including the ones you would not have eaten. Left lying, they carry weevil grubs into the soil to emerge under the same tree next season. This half day of work is the single most effective pest control in the chestnut year.
Do not throw culled nuts into the hedge or a cool compost pile. Burn them, bin them, or feed them to poultry or pigs run under the trees after harvest.
The year at a glance
The table below sets out what to do and, more usefully, what to be looking at in each part of the year. The judgement calls are all in the middle column: what you see decides whether the season is going well or whether something needs attention while it is still cheap to fix.
| Season | What to look at | What to do |
|---|---|---|
| Late winter, dormant | Bark for sunken cankers; the shape of the frame | Structural pruning; remove cankered limbs; check ties and mulch |
| Early spring, bud swell | Whether growth is starting evenly across the crown | Stop pruning; clear grass circles; prepare the harvest floor |
| Late spring | Extension growth and leaf color on young trees | Water young trees deeply in dry spells; mulch to the drip line |
| Early to midsummer, flowering | Pollen shed dates and female receptivity on each tree | Record the dates; do not disturb the canopy |
| Midsummer | Burr set; any limb browning off on its own | Water in drought; trace and cut out blight early |
| Late summer | Burrs sizing up and turning from green to yellow-brown | Mow the ground short under the full canopy spread |
| Early autumn, drop begins | Burrs splitting on the tree; first nuts on the ground | Start daily pickup; float-test and cure each batch |
| Mid autumn, peak drop | Rate of fall; weather, warmth and rain | Collect twice daily in warm or wet spells; keep sorting |
| Late autumn, drop ends | Leftover nuts, burrs and culls on the ground | Rake and destroy all remaining nuts; record the season's totals |
| Early winter | Storage bags for soft or moldy nuts | Check the refrigerator weekly; write up the year's notes |
What to carry forward each year
Keep four numbers for every season: the pollen shed and receptivity dates for each tree, the date the first burrs split, the total weight gathered, and the percentage that floated. Add the position of any canker you cut out and the date you cut it.
Individually none of these is dramatic. Together, over four or five years, they tell you whether your pair of trees genuinely overlaps in flowering, whether weevil pressure is rising or falling with your pickup discipline, and whether blight is moving through the planting. A chestnut planting is a twenty-year project and none of those trends is visible in a single season.