Crabapples are versatile, small, ornamental trees used in the urban landscape. Crabapples bloom in spring, usually in May, bearing flowers that vary a great deal in color, size, fragrance, and visual appeal. It is common for flower buds to be red, opening to pink or white flowers. The fruit ripens between July and November, and varies in size from ¼”to 2” long or wide. Crabapples thrive in full sun and grow best in well drained, slightly acidic soils (pH 5.5-6.5); however, they will grow well in many soil types. Most crabapple selections tolerate the cold winters and hot, dry summers prevalent in the Midwest. For many years, crabapple cultivars have been selected on the basis of their flowers, but with some cultivars, undesirable features, such as disease problems and early fruit drop, outweigh their short-lived spring beauty. No single cultivar can fulfill every landscaping need. Consider the following information when choosing a crabapple cultivar for your landscape.
Disease resistance should be your first consideration. Many resistant cultivars are available and recommended in order to avoid the most common disease problems. Before making a selection, keep in mind that not all crabapples do well in every location. Disease intensity varies from region to region, and disease strength can vary from year to year. For instance, some crabapples will be more prone to disease susceptibility in areas with greater rainfall than in drier climates. Careful consideration of the following information will be helpful in choosing the right crabapple cultivar. There are four diseases that seriously affect crabapple:
Apple scab is one of the most serious diseases as it leads to early defoliation of the tree. It is a fungal disease, which develops in cool, wet springs. On susceptible crabapples, apple scab causes spotting of the leaves, premature defoliation, and unsightly spots on the fruit. There are numerous cultivars that are resistant or very tolerant (still susceptible but with little defoliation) so choose one based on its resistance.
Cedar-apple rust is a less serious leaf-spotting disease common to our native crabapple cultivars. It is usually a problem in areas where native junipers (Juniperus) are planted. Selecting resistant cultivars can control this disease.
Powdery mildew is a fungal disease that can cause considerable damage to leaves of susceptible cultivars without threatening the health of the tree. Poor air circulation, close association with susceptible apple cultivars, and humid weather conditions will greatly influence disease incidence and severity.
Fire blight is a serious bacterial disease of crabapples. Though it is less common then the others, if left untreated it can be fatal to susceptible crabapple cultivars. Select resistant cultivars.
Crabapples vary greatly in their shape and size. The mature size of the plant should be considered in your selection. The size of the landscape and the surrounding structures will dictate the plant size for a given space.
Trees only produce fruit after they have had flowers. The ornamental fruit of a crabapple puts on a show during the fall and winter. Fruits vary from less than ¼” to 2” in diameter. By definition, Malus trees with fruit larger than 2” are not crabapples, but apples. The best crabapple selections have small fruit, less than one-half inch, with bright, attractive colors (red, orange, and yellow). Some cultivars have showy fruits after hard frost, persisting (staying on the tree) throughout the winter, and providing food for birds. The non-persistent cultivars often produce fruit that can create an unwanted mess, especially when located near a driveway or sidewalk.
Although flowers are usually the first consideration when choosing a crabapple, they should be one of the last. Flowering period is usually short, with bloom length dependent on the weather. Flowers may be single, double, or semi-double and colors vary from white, pink, or red. Flowers also have three distinct stages when blooming, from tight bud to balloon, and full bloom, often changing color with each stage.
Light pruning is useful for keeping plants healthy, improving form, and correcting structural problems. Prune in late winter or just after flowering. Remove dead, diseased, or broken branches at any time. Occasional thinning of the crown allows light into the center of the tree, and is done by removing a few smaller branches back to a branch angle. Heavy cuts of one-inch or more should be avoided since they induce excessive water-sprout growth that will ultimately fill in the tree center. Suckers from the base of the trunk are problems with many types of crabapples and should be pruned as close to the ground as possible each season. It is important to disinfect pruning tools after each cut since pathogens can be spread by pruning tools.
- Family (English) Rose
- Family (botanic) Rosaceae
- Planting site City parkway, Residential and parks, Under utility lines, Wide median
- Tree or plant type Tree
- Foliage Deciduous (seasonally loses leaves)
- Native locale Chicago area, Illinois, North America
- Size range Large shrub (more than 8 feet), Compact tree (10-15 feet), Small tree (15-25 feet), Medium tree (25-40 feet)
- Mature height 15-20 feet
- Mature width variable
- Light exposure Full sun (6 hrs direct light daily)
- Hardiness zones Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
- Soil preference Moist, well-drained soil
- Tolerances Alkaline soil, Dry sites
- Season of interest early winter, mid spring, late spring, late summer, early fall, mid fall, late fall
- Flower color and fragrance Fragrant, Pink, Red, White
- Shape or form Oval, Pyramidal, Round, Upright, Vase-shaped
- Growth rate Moderate
- Transplants well Yes
- Planting considerations Excessive sucker growth, Messy fruit/plant parts
- Wildlife Birds, Migrant birds, Small mammals
- Has cultivars Yes
