Analysis of Japanese Quince

The Shrub

• Japanese quince is a deciduous shrub that stays fairly low, only about 3 feet in height, but spreads to as much as 6 feet wide in a jumble of densely packed branches. Its dark green leaves are oblong, 1 to 2 inches in length, with toothed edges. The shrub produces deep red-orange flowers in the very early spring or late winter, before its leaves emerge. After the flowers come apple-like fruits that ripen by early fall.

Fruit

• The fruit of the Japanese quince is yellowish-green and about 1-1/2 inches in diameter. Its flesh is very firm, and ripe fruits are fragrant. The fruit is edible, but its flavor is too bitter to be palatable to most people. The bitterness diminishes when the fruit is cooked, however, and quince often is used to make jams and jellies. The shrub flowers on new growth, and pruning immediately after flowering will increase the number of blooms for the following season. However, removing the current year's flowers will decrease the fruit yield for that season.

Growing Requirements

• Japanese quince is undemanding and will grow well in many different types of soils, including dry soils, with a minimum of care. It is hardy in U.S. Department of Agriculture hardiness zones 5 to 9, but flower buds may be damaged during especially cold winters or spring frosts. The shrub prefers full sun, but will tolerate partial shade; it flowers best in full sun, however. In soils with high pH levels, the shrub's foliage will turn yellow because the plant's roots won't be able to absorb minerals adequately from the soil.

Pests and Problems

• In wet conditions, Japanese quince is vulnerable to fungal leaf spot, which can cause its leaves to drop. It can be susceptible to fireblight and apple scab, diseases that also affect apple and pear trees. Fireblight is a bacterial disease, and apple scab is caused by a fungus. Insect pests that tend to attack Japanese quince include aphids, scale insects and mites.