Crabapple

Crabapple (Crab Apple in Europe) is a term used for several species of Malus in the family Rosaceae, which are characterized by small sour fruit resembling familiar table apples (Malus domestica). They are usually small trees or shrubs.

photo courtesy Susan Sweeney

The crabapple fruit is not an important crop. The plants are grown primarily as ornamentals, although a few growers produce the fruit commercially. The fruit is preserved or pickled or it is used in making jellies. Most crabapples are grown for their ornamental value, and cultivars are chosen because of their beautiful flowers, foliage, or fruit.

The general appearance is similar to a small bearing apple tree. Culture is also similar to the culture of apple trees. When planting around a home it is wise to choose disease resistant varieties. Some varieties, such as Dolgo, are propagated for large size and eating qualities. Crabapple fruit is extremely sour and woody and it cannot be eaten raw for this reason. However if crabapples are stewed and the pulp is carefully strained and mixed with an equal volume of sugar then boiled, their juice can be made into a delicious ruby-coloured crabapple jelly. A small percentage of crab apples in cider makes a more interesting flavor.

photo courtesy Susan Sweeney

The flower is similar to that of the apple. Bees freely visit the flowers, for both nectar and pollen. Like the apple, the crabapple appears to require cross-pollination between cultivars by insects. All native crabapples are self-sterile. Self-pollination is impossible and that pollinating insects are absolutely needed. Considering that the only difference between the crabapple and the apple is fruit size, it seems reasonable that the most effective pollinator of apples, the honey bee, should be equally effective on the crabapple.

Crab apple species freely hybridize among themselves and with domestic apples. They produce copious and highly fertile pollen, thus are used as pollenizers in apple orchards. Varieties of crab apple are selected to bloom contemporaneously with the apple variety in an orchard planting, and the crabs are planted every sixth or seventh tree, or limbs of crab are grafted onto some of the apple trees. In emergencies a bucket or drum bouquet of crab apples blossoms are placed near the beehives as orchard pollenizers. See also Fruit tree pollination.

Some crab apples are used as rootstocks for domestic apples to add beneficial characteristics. For example, Siberian crab rootstock is often used to give additional cold hardiness to the combined plant for orchards in the northern part of apple range.

Some other species that are called crab apples include:

• Malus augustifolia, Southern crab, native to southeastern USA
• M. baccata, Siberian crab, native to northern Asia
• M. coronaria, American wild apple, native to central USA
• M. floribunda, Japanese crab, native to Japan
• M. fusca, Oregon crab, native to western USA
• M. silvestris, European crab, native to Europe

External links:

• Disease ResistantCrabapples: Vermont Extension
• Crabapple Pollenizers for Apples: Ontario Ministry of Agriculture and Food
• Preparing and Canning Crabapple Jelly: University of Georgia