Why Is My Blackberry Not Producing Fruit?

Blackberry plants that grow vigorously but never bear fruit are almost always experiencing a management issue rather than a fundamental plant problem. Blackberries are extremely productive when grown correctly — a single well-managed plant can yield several kilograms of fruit annually. When they fail to produce, the cause is usually incorrect pruning, wrong cane management, very young plants in their first year, or a site problem that is suppressing flowering.

Pruning away the fruiting canes

Blackberries bear fruit on canes that are in their second year of growth — called floricanes. First-year canes (primocanes) grow vegetatively, then in their second year they develop lateral fruiting shoots, flower, fruit, and then die. If you remove all canes from the plant each winter (cutting to ground level), you are removing the second-year canes that would have borne fruit. Instead, remove only the canes that have already fruited (dark, woody, this season's fruited canes) and keep the current-season's new green canes tied in for next year's fruiting.

Plant is in its first year

A new blackberry plant planted this year will produce only first-year canes (primocanes) in its establishment season. These canes fruit the following year. In the first year, no fruit is produced — this is completely normal. The plant is building its root system and producing the canes that will fruit next season. Expect the first significant harvest in year two.

Deep shade

Blackberries tolerate more shade than most fruiting plants but require at least three to four hours of direct sun per day for productive flowering and fruiting. In deep shade, the plant grows vigorously but fails to initiate enough flower buds for a worthwhile harvest. Improve light by pruning back overhanging trees or consider moving the plant to a sunnier position if shade is extreme.

Excessive nitrogen

Very rich soil or high-nitrogen feeding drives vegetative cane growth at the expense of flower-bud initiation. Avoid fresh manure applied directly to blackberries. Switch to a balanced or potassium-dominant feed if you have been applying high-nitrogen fertilisers.