Gadenin日本語Get the appThe year at a glance
Unlike most citrus, a mature yuzu in a cold garden stays outside all year, so its calendar is set by the local seasons rather than by moving a pot in and out. It makes one main growth flush, flowers once, and carries fruit through most of the growing season. The table assumes an established tree in the ground; a tree in its first three winters needs the extra protection described in the last section.
| Season | Feed | Water | Main jobs |
|---|---|---|---|
| Late winter | None yet | Rain is usually enough | Prune before buds swell, remove suckers, check ties and stakes |
| Early spring | Start balanced citrus feed | Water if a dry spell runs over two weeks | Remove winter row cover from young trees, top up mulch |
| Late spring | Every 3-4 weeks | Keep evenly moist through flowering | Flowering, then the natural fruitlet drop |
| Early summer | Every 3-4 weeks | Deep weekly soak in dry weather | Thin the crop once the drop ends, watch the new flush for leafminer |
| Midsummer | Last feed of the year | Never let it dry out while fruit is sizing | Check for scale, keep the mulch topped up |
| Late summer | Stop feeding | Reduce as growth slows | First green pick, no pruning, no nitrogen |
| Autumn | None | Reduce | Fruit colors and is picked, clear fallen fruit and leaves |
| Early winter | None | None needed | Row cover young trees before hard frost, mulch the root zone deeply |
Late winter and spring: cut first, then feed
The pruning has to be done before the buds swell, and it is the only major cutting the tree gets. Take out rootstock suckers, dead wood and crossing branches, cap the height, and stop. Wait until buds actually move before writing off frost-damaged shoots, because yuzu wood that looks dead in late winter often breaks bud a few weeks later.
Start feeding as soon as new growth extends, with a balanced citrus fertilizer, and keep to it every three or four weeks. The aim is one strong early flush that hardens well before the leafminer season, so early feeding is worth more than heavy feeding.
Flowering follows in late spring, and yuzu is self-fertile, so a single tree sets fruit on its own without a pollination partner. The flowers are strongly scented and insects find them readily; there is nothing to do at this stage except keep the roots evenly moist, because a dry spell during flowering causes flowers to drop.
Summer: thin, then leave it alone
Three to six weeks after flowering the tree sheds a large proportion of its fruitlets by itself. That drop is normal and is not a failure. What matters is what you do immediately after it: on a heavily set tree, thin the remaining fruitlets while they are still around three quarters of an inch (2 cm) across, spacing what stays roughly a hand's width apart along each branch. Thinning at this point is the single most effective action of the whole year, because it protects next season's flowering as well as this season's fruit size.
Water deeply once a week in dry weather rather than lightly and often, and keep two to three inches (5-8 cm) of mulch over the root zone with a gap around the trunk. Drought while fruit is sizing causes a second wave of fruit drop and shuts down next year's flower buds.
Take the last feed by midsummer and stop. This is the discipline that most separates a yuzu from other citrus: everything from late summer onward is about hardening the wood for winter, and nitrogen after midsummer works directly against that. Inspect the joints where leaf stalks meet the stems for the small brown or white bumps of scale, and treat with horticultural oil in the evening if you find them building.
Autumn and winter: harden off and protect
From late summer the fruit is full size and the first green pick is available. Take a share then, both for its sharper aroma and because it lightens the load, then let the rest color through autumn. Pick everything before a hard freeze, because frozen rind loses its oil quality and will not store.
Do not prune, do not feed, and do not water beyond keeping the tree from drought stress. A yuzu going into winter should have firm, fully hardened wood and no soft growth on it at all.
Clear fallen fruit and leaves from beneath the tree rather than leaving them under the mulch. Then, for a tree in its first three winters, wrap the trunk and lower framework in row cover before the first hard frost and pile eight inches (20 cm) of loose mulch over the root zone, keeping it off the bark. Uncover on mild days for light and remove the row cover entirely when nights stay above freezing. From about the fourth winter an established tree in open ground generally needs nothing.
The five dates that run the tree
The whole calendar reduces to five entries, and if you record only these you can run a yuzu properly from the second year on. Write down the date you pruned and roughly how much you took, the date of full flowering, the date the natural fruitlet drop finished and whether you thinned, the date of the first green pick, and the date of the final harvest with the count or weight.
The gap between flowering and the final pick is your own tree's ripening interval, which no general guide can give you. The pruning entry paired with next year's flowering shows whether you cut too hard. And the year-by-year harvest total is the only way to see a heavy year and bare year cycle forming while there is still time to break it by thinning.
Add one winter line as well: the lowest temperature the tree saw, whether you protected it, and how much damage showed the following spring. After three winters that gives you a hardiness figure for your own garden and tells you when it is safe to stop wrapping.