Goji Berry Care: Watering, Feeding and Keeping the Stems Off the Ground

Feed lightly, or not at all

Goji comes from poor dry ground and it behaves accordingly. Given rich soil and regular nitrogen it makes enormous quantities of soft leafy stem, flowers late and sparsely, and produces fruit that never firms up. This is the most common way to end up with a large healthy-looking goji that has never given you a decent crop.

An established plant in open ground needs a single light scatter of a balanced general fertilizer as growth starts in spring, at roughly 2 ounces per square yard (60 g per square meter), and nothing else all year. Skip it entirely on fertile soil. If the leaves are mid-green and the plant is throwing several strong new stems, it has everything it needs.

Container plants are the exception, because watering flushes nutrients out of a pot. Give a container goji a balanced liquid feed every three or four weeks from the start of growth until flowering finishes, then stop. Feeding into late summer pushes soft growth that will not have hardened before the first frosts.

Watering: less than you think, except at flowering

An established goji in open ground is genuinely drought-tolerant and will survive a summer without a drop. Surviving and cropping are different things, though. The window that matters runs from the first flowers opening through to the end of picking, which on goji is unusually long because the plant flowers and fruits in overlapping waves for months. Drought during that stretch makes flowers drop before they set, and the fruit that does set stays small and does not color properly.

Through a dry spell in that window, give an established plant 3 to 4 gallons (14 to 18 liters) a week in one long soaking at the base rather than frequent light sprinkles. Outside that window, in early spring and after picking finishes, leave it alone. Goji roots rot in wet soil far more readily than the plant suffers from dryness, and the commonest way to kill an established goji is kindness with a hose in winter.

In a container, check the top 2 inches (5 cm) of the mix and water when it is dry, which in high summer may be daily. Do not let a fruiting container plant wilt: goji recovers from wilting without visible harm, but the flowers and small green fruit present at the time drop, and that is the crop gone.

Tying in, and the stems that root where they touch

A goji stem grows long, thin and flexible, and by late summer a strong one can be 8 to 10 feet (2.4 to 3 m). Left alone it arches over under its own weight until the tip reaches soil, and there it roots within a few weeks. The new rooted point throws its own stems the following year, still joined to the parent, and this is how a single plant walks across a bed and becomes a thicket. It is not slow: two seasons of not looking is enough.

The answer is a support and a habit. Put in three or four canes, a tripod, or a couple of horizontal wires along a fence, and tie the main stems up as they extend, using soft string in a figure of eight. Then walk round the plant every two or three weeks through the growing season and deal with anything heading downwards, either tying it up or shortening it. This takes a couple of minutes and it is the single most useful thing you do for a goji.

If a tip has already rooted and you do not want a new plant there, cut the connecting stem, then dig the rooted point out completely rather than pulling the top off. Goji regrows from root fragments, so leaving the root in place means the same shoot comes back the following spring.

1. Walk the plant every two or three weeks Look along the outside of the plant at knee height and lower for stems arching towards the soil. Tie up anything within a foot of the ground, or shorten it by a third. Do this from late spring through to the end of summer, when stem extension is fastest.
2. Pull suckers, do not cut them Shoots appearing away from the crown come from roots running sideways. Pull them out with a sharp sideways tug so the shoot tears away at its base, taking the growing point with it. Cutting a sucker at ground level leaves the base behind and it comes back with two or three shoots instead of one.
3. Keep a clear strip around the plant Maintain 3 feet (90 cm) of mown grass or hoed bare soil around an open-ground plant. Escapees show up immediately against a clean surface, and mowing alone kills most suckers before they get established. Suckers hidden in a border are found years later.
4. Check ties before autumn gales Soft string cuts into thickening goji stems over a season. Loosen or replace ties in late summer, and check every tie again before the windy part of the year, because a stem that works loose in a gale ends up lying on the soil, which is exactly where you do not want it.

Bruised leaves, blackened stems and other things that look worse than they are

Goji foliage bruises very easily. Push through the plant to pick, and the leaves and young stems you brushed against will be blackened and limp a day or two later, in the exact pattern of your hand and arm. It looks like a fungal disease and it is not. The plant is unharmed, the blackened leaves drop, and new growth continues. Knowing this saves people from spraying a healthy plant.

It does mean picking and pruning benefit from a light touch. Work from the outside in rather than shouldering your way through, support a stem with one hand while you pick with the other, and prune with something sharp so you are cutting rather than crushing. A plant tied to a support and cut back annually is far easier to move around inside than a sprawling one, which is another argument for keeping up with both jobs.

Goji also drops a lot of leaves in a dry spell and regrows them when water returns. Sudden leaf drop in high summer on an unwatered plant is a drought response, not a disease, and the plant recovers. It does cost you the fruit that was setting at the time.

Note the date you first tied stems in each year and how many main stems you are carrying. Stem count is the number that predicts the crop on a goji far better than plant size does, and it is the figure that tells you whether last winter's pruning was too hard or too soft.