Goji Berry

Even moisture through bloom and fruit sizing

Give about an inch of water a week, ideally on drip, and aim for steady soil moisture rather than swings between soaked and bone dry. Watch this most closely during bloom and while fruit is sizing. Goji is prone to blossom end rot, which is a localized calcium deficiency rather than a disease. Calcium travels to the fruit dissolved in water, so when soil moisture swings the plant cannot move it to the far end of the berry fast enough and that tissue collapses, even where soil calcium is perfectly adequate.

First feeding at budbreak, one of three splits

Budget 4 to 5 tablespoons of 16-16-16 per 10 square feet for the year and split it into three roughly equal applications: the first now at budbreak, the second at flowering, the third as fruit ripens. Cut the rate on soils that are already fertile. Splitting the year's nitrogen across budbreak, bloom, and ripening matches supply to the three points where the plant is actually building tissue. A single heavy dose pushes leafy growth at the expense of fruit.

Dormant pruning: open the shrub and shorten last year's laterals

While the shrub is leafless and dormant, cut out weak, dead, and damaged wood, then shorten the lateral branches back to somewhere between 6 and 18 inches. Keep three to five strong side shoots as the permanent frame. Skip this entirely in the first year and let the plant build roots. Goji carries its crop on lateral shoots off the current season's growth, so heading the laterals while dormant is what forces out the new fruiting wood. An open canopy also dries faster after rain, which is most of the powdery mildew control.

Summer: pinch the shoot tips and pull the root suckers

Pinch the top two to three inches off vigorous new shoots to force side branching, trim shoots sprouting directly off the main trunk, and pull out root suckers and sprouts rising from the base. Once the trunk reaches 16 to 18 inches, cut its tip to push side branches. Most fruit forms on lateral branches, so pinching a tip turns one long unproductive whip into several fruiting laterals. Goji suckers aggressively from the roots and will build itself into a thicket that shades out its own fruiting wood if the sprouts are left standing.

Scout for powdery mildew in the crowded interior

Through summer, check leaves for white powdery patches, working from the shaded interior of the shrub outward. Thin crowded branches to move air through the canopy. Horticultural oil can slow the spread once mildew is already present. Powdery mildew takes hold on foliage that stays still and damp, which is exactly the interior of an unpruned goji. Air movement and faster leaf drying do most of the work a spray would otherwise have to do.

⚠ If you reach for horticultural oil, do not apply it during bloom while pollinators are on the flowers.

Goji gall mite: 2 percent horticultural oil at leaf drop

Spray a 2 percent horticultural oil solution in fall just before the leaves drop, or alternatively in spring just as the leaves emerge. Cover the stems and buds thoroughly rather than just wetting the foliage, since that is where the mites sit. The goji gall mite runs six to seven generations a year and is too small to see until the galls have already formed, so once the season is underway you are permanently behind it. A dormant oil smothers the overwintering mites and knocks the starting population down before it can compound.

⚠ Keep this oil off the plant during bloom. Goji flowers continuously from midsummer until frost, so any in-season miticide lands on open flowers and the bees working them - the fall or spring timing sidesteps that completely. Oil is a contact material only and needs full coverage to do anything. Do not apply horticultural oil within 30 days of a sulfur application, and avoid spraying under freezing or drought-stressed conditions.

Net the shrub as the first berries color up

Drape bird netting over the shrub as soon as the earliest berries turn orange-red, and fence the base if rabbits or deer browse your area. Birds and squirrels strip ripe goji, and because this crop ripens as a long trickle from midsummer to frost instead of all at once, an unnetted shrub gets picked over daily for months rather than losing one harvest.

Pick at full color, about 35 days after full bloom

Harvest when berries reach full color, roughly 35 days after full bloom, and keep picking into late fall. Hand pick only, pulling each berry slightly to the side so the stem stays on the plant. Go over the shrub repeatedly rather than stripping it once: in warm weather around 68 to 77 F expect to pick about every 10 to 15 days, eight to ten times a season (UF/IFAS HS1391), and expect longer gaps between pickings in cooler climates or late in the season. Goji sets flowers continuously, so ripe and green fruit hang on the plant together and it has to be picked repeatedly rather than stripped once. Pulling a berry straight out tears the peduncle off with it, which wounds the shrub and shortens how long the fruit keeps.