Why Does My Quince Tree Look Unhealthy?

Do the fruits have small brown spots that enlarge and grow fuzzy in humid weather?

Are the growing shoots wilted or dying, a gummy exudate is present?

Are the fruits surrounded by brown, crumbly excrement?

Do the young fruits have crescent-shaped scars on them?

Are there webbed nests in tree branches full of caterpillars?

Did the leaves suddenly blackened, and the tips of growing shoots bend over?

Are there any dark red or brown spots on leaves?

These symptoms are caused by fungal disease - Brown rot. Other symptoms of brown rot may be withered blossoms, mummified fruits, brown leaves, and small tan cankers with dark margins on twigs. Remove and destroy both mummified fruits and twigs or branches with gummy lesions. For more control, spray sulfur early to protect blooms, then again later to protect the fruit.

These symptoms may indicate twig borers. These small caterpillars tunnel into growing shoots and fruits and feed on the inside. Prune off the affected fruits and shoots below the entry point and destroy them. If you find holes in larger branches, slide the wire into the hole to kill borers inside.

Brown, crumbly excrement that surrounds quince fruits are caused by Codling moth larvae. These white or pinkish caterpillars feed by tunneling through the fruit. Control is very difficult without using chemical insecticides. You can kill their eggs by spraying superior oil on leaves and twigs 2-6 weeks before blossoming. One of the effective methods of control is biological insecticide CYD-X, codling moths granulosis virus.

Crescent-shaped scars on fruits are caused by beetles - Curculios. You can control their numbers by gently shaking the tree and the branches or hitting the branches with a padded mallet and when the bugs fall, collect and destroy them. If you do this twice a day, you won't have trouble with them.

Tent caterpillars can be controlled by manually destroying their nests or egg cases, spraying leaves with BTK at the first sign of damage, or applying pyrethrin spray as a last resort.

These symptoms indicate a bacterial disease Fire blight. Control fire blight during the growing season by pruning off branches a foot below infected sections. Between each cut, dip pruning shears into isopropyl alcohol or a 10 percent bleach solution to prevent spreading the disease as you prune.

Fungal disease leaf blight often attacks quince leaves and twigs. Prune off all infected leaves and twigs to stop the disease from spreading. Thin plants to increase air circulation and allow sunlight to reach inner branches. Rake and destroy all fallen leaves and fruit.

If the leaves covered by small bumps the culprits are scales. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.