With more than 35 species and 700 varieties, the crab apple is one of the most popular trees used in garden landscaping. Closely related to the apple tree, the crab apple tree bares smaller edible fruit. Its relatively small size makes it ideal for residential landscaping, fitting on small lots and neatly under power lines.
Flowers of the crab apple tree are similar to the flowers found on apple trees. Both have five petals and 15 to 20 yellow stamens in the center. Crab apple tree flowers typically start out a deep pink and gradually fade or lighten as they open. Flowers bud and begin to open before leaves develop creating a pink cloud effect. Blooming takes place between April and May depending on the region and temperature.
Fruits from crab apple trees are less than 2 inches in diameter. Anything larger is classified an apple. Several varieties are as small as a quarter inch in diameter. Some species are more valued for their show of fruit than for their flower displays. Fruits are on the tree longer than the flowers and within the crab apple family come in a variety of colors ranging from yellow and orange to purples and the traditional bright reds. With some lasting well into winter, crab apple trees make a showy display long after the flowers and leaves have gone. This can be an added benefit for bird lovers, too, as the fruit is a food source.
With as many varieties as are available, it is not surprising that crab apple trees also come in a variety of sizes and shapes. Most range between 15 and 25 feet in height but some can climb to 50 feet tall. They come in vase-shaped, columnar, spreading and even weeping types, creating many choices for the landscape designer or weekend gardener. Fall leaf colors also cover the gamut providing red, yellow, orange or purple displays depending upon the type.
Crab apple trees grow well in just about any soil type but seem to prefer clay or sandy clay loams. They prefer full sun and will perform poorly if heavily shaded. Planting them in hot southern or western exposed terrains could cause premature budding which might result in exposure to a late frost. Crab apple trees handle drought well. They seem to prefer mulched beds with a drip irrigation system.
Remove sucker growth, the new shoots that sprout around the base of the trunk. Crab apples are usually grafted on other apple tree stock and the shoots will be from the original tree causing a mixed look if allowed to grow. Prune annually in the spring prior to budding of flowers to remove dead or damaged branches, limbs that cross over, rub against each other or grow toward the center of the tree. It is important to maintain an open, scaffold appearance to allow air flow and light penetration.