Gadenin日本語Get the appFeeding is the fastest way to lose the crop
Chinese bayberry carries nitrogen-fixing nodules on its roots. In partnership with a soil bacterium it converts atmospheric nitrogen into a form it can use, which means an established tree in reasonable soil is already fed. Adding nitrogen on top of that does not produce a bigger crop; it produces a bigger tree with less fruit on it.
The symptoms of an overfed bayberry are easy to read. Shoots extend two or three feet (60 to 90 cm) in a season instead of the normal one, the leaves are large, soft and a very dark glossy green, growth continues far too late into autumn, and flowering thins out. Fruit that does set on such a tree is often watery and drops early. Trees pushed this way are also noticeably more prone to winter damage, because soft late wood does not harden off in time.
If you must feed, and the only real case is a tree on very poor, thin, sandy ground that is making under six inches (15 cm) of new shoot a year, use a low-nitrogen fertilizer with potassium and phosphorus, applied lightly in early spring, and stop as soon as growth recovers. Potassium supports fruit size and sugar and rarely does harm; nitrogen is the one to avoid.
| Input | Effect on the tree | Use it? |
|---|---|---|
| Nitrogen fertilizer or manure | Long soft shoots, poor flowering, late growth | No |
| Potassium in early spring | Better fruit size and sweetness | Sparingly, on poor soil |
| Lime or wood ash | Raises pH, causes yellow leaves with green veins | Never |
| Pine bark or pine needle mulch | Holds moisture, keeps pH low, protects surface roots | Yes, every year |
| Rich garden compost around the trunk | Feeds nitrogen and holds damp against the bark | No |
Watering: deep, occasional, and never standing
The root system is shallow and wide, running mostly in the top foot (30 cm) of soil and spreading well past the branch tips. That shape means the tree dries out sooner than its size suggests in a hot spell, but also that it drowns quickly in ground that holds water. Both problems are solved by the same habit: water deeply and then let the surface dry before watering again.
For the first two years after planting, water thoroughly once a week in the growing season and twice a week in hot, dry weather, giving enough each time to wet the soil to the full depth of the roots. After the third year an established tree in normal ground needs watering only during genuine drought. Check by pushing a finger three inches (8 cm) into the soil under the mulch; if it is dry at that depth, water.
The exception is the few weeks when fruit is swelling, between petal fall and color change. A tree that dries out badly during that window sheds a proportion of its crop and the fruit that stays on stays small. Keep the soil evenly damp through that period, then ease off as the fruit begins to color. Heavy watering right at ripening does the same damage that heavy rain does, splitting the skins.
Water at the ground, not over the canopy. Evergreen bayberry foliage is dense and slow to dry, and overhead watering in warm weather encourages the leaf and twig fungal problems that spoil the following year's fruiting wood.
Mulch does most of the work
Because the feeding roots sit so near the surface, they suffer from heat, from drying and from anything you do to the soil above them. A permanent organic mulch fixes all three. Spread three to four inches (8 to 10 cm) of pine bark, pine needles, shredded leaves or wood chips over the whole root area out to the drip line, and top it up once a year as it breaks down.
Keep a clear ring a hand's width wide around the trunk. Mulch piled against bark holds moisture there and causes collar rot, which kills trees that were otherwise thriving. Never dig, hoe or rotavate under the canopy; you will cut the surface roots the tree depends on. If weeds come through the mulch, pull them by hand or lay more mulch on top.
Through the seasons, and what to record
In spring, as growth starts, check the mulch depth, clear any weeds and look over the tree for winter-damaged twigs. Through summer the tree needs little beyond water in dry spells and watching the fruit as it swells. After harvest comes the one main pruning of the year. In autumn resist the urge to tidy or feed, and let the wood harden. In winter an established tree is hardy to roughly 14F (minus 10C); younger trees appreciate a thicker mulch over the roots and shelter from cold drying wind.
Keep a simple yearly log: the date the tree first flowered, the date the fruit began to color, the date you harvested, roughly how much you picked, and any watering you did in the weeks before that. After three seasons the pattern is obvious. You will be able to predict harvest within a few days from the flowering date, and you will see straight away whether a poor year came from drought at swelling, rain at ripening, or something you did in the pruning the previous year.