Why Do My Blueberries Look Unhealthy?

Are the berries soft and mushy?

Are the berries shriveled and webbed together with silk?

Do the berries drop early, mature berries turn gray, shrivel and harden up?

Are the blueberries blossoms, leaves and twigs covered with brown splotches or brownish-gray mold?

Are the new leaves yellow with green veins?

Have the canes died back?

Are there any reddish, conical stem swellings that may have become blisterlike?

Have the leaves been skeletonized?

Blueberry maggots are small white maggots that feed

This type of damage could have been caused by two kinds of fruitworms, Cherry fruitworm, and cranberry fruitworm. Berries will contain sawdust-like material and either a white caterpillar (cherry fruitworm) or a yellowish-green caterpillar (cranberry fruitworm). To reduce damage from these pest harvest berries frequently and destroy infested fruit to prevent larvae from maturing.

Mummy berry is a fungal disease that overwinters on dried, diseased berries called mummies and spreads most rapidly in cold, wet springs. Control mummy berry by picking all mummies off the plant. In the spring cultivate around bushes to bury dropped mummies, or add mulch to cover the remaining fungal spores.

Iron deficiency causes leaves to turn yellow with distinct green veins. The soil usually has sufficient iron but is not acidic enough to make iron available to the plant. Spray leaves with iron salts or chelates for quick relief of symptoms. A long-term solution is to reduce the soil pH by mulching with an acidic material, such as pine needles.

Blueberry cane canker is a fungal disease common in the South. Prune off all infected branches and sterilize pruning tools between cuts in isopropyl alcohol. If this disease is a problem in your area, plant rabbiteye blueberries, which are not susceptible to cane canker.

Fusicoccum canker is a fungal disease more common in colder regions, begins as red stem spots that enlarge and develop a bulls-eye pattern. Prune off all infected branches and sterilize pruning tools between cuts in isopropyl alcohol. Resistant cultivars include ‘Berkeley', Blueray', ‘Burlington, ‘Coville'. and ‘Rubel'.

Skeletonized leaves are caused by Japanese beetles. Adults of these insects devour leaves, stalks, and flowers of nearly 300 plant species. Their larvae feed on the roots of the plants. Handpick adult beetles into a can of soapy water but make sure to wear gloves as Japanese beetles are blister beetles. Apply parasitic nematodes to the soil to limit beetle grub populations. Use pyrethrin powder or neem oil as a last resort.

If the fruits have disappeared the most probable culprits are birds. Birds love blueberries so much that unprotected bushes are often stripped clean of berries, even before they are fully ripe! The only sure protection is a net draped over the planting and held to the ground to prevent birds from getting underneath.