Ornamenal Crabapples

Who hasn’t thrilled to the sight of a crabapple in full bloom at the height of spring? They’ve been a favorite in landscapes for years-spectaculor when in bloom, compact in size, available in a variety of growth habits, and a source of food for wildlife in the depths of winter.

Technically, crabapples are defined as those apples with fruits two inches or less in diameter. At maturity the majority range in height from 15 to 25 feet. They are ideal for planting near houses or in small yards. You can buy them in a varity of shapes: spreading, weeping, columnar, vase-shaped or pyramidal. Some types have a horizontal branching habit, but most are upright.

What they’re really treasured for is their flowers and fruit. Flowers range from white through pink to a rosy-red. Some show pink in the bud, opening to display white petals. Flowers are either single (5 petals), semi-double (6 to10 petals), or double (more than 10 petals). Most bloom here from early to mid-May.

Then there are the fruits. These vary from pea size to 2 inches in diameter, and range from green to yellow to red. Some drop in the fall, but others remain hanging on the tree into winter - like jewels. The large fruited types can be used to make preserves. Those that persist into winter provide food for robins, cedar wax wings, finches and other birds.

Flowering crabapples grow best when you plant them in a sunny, well-drained site. Dig a planting hole that is 2 to 3 times wider than it is deep. Plant your new tree at the same depth it was in the nursery (indicated by a soil line on the trunk or root system). Do not plant your tree too deeply; recent research has shown that more trees die because of improper planting than for any other reason. Mix in organic matter like peat or compost only if the soil is very sandy or a heavy clay. Prune only to remove water sprouts, suckers, branches out of place and diseased or damaged wood. The most serious insect is aphids and these can be easily controlled with insecticidal soaps. During the first year make sure your tree receives the equivalent of an inch of rain each week. Water deeply once a week rather than in sporadic bursts. Wait until next year before fertilizing.

Unfortunately, crabapples are susceptible to four major diseases which can cause early defoliation, disfigurement and weakening of your trees. Apple scab is the most common and most serious of the diseases. It shows up on leaves as olive green spots with a velvety, grayish surface. In July leaves often turn yellow or orange and drop from the tree. Fireblight causes the leaves to blacken, shrivel and hang down. Cedar apple rust shows up as bright yellow to orange spots on the upper leaf surfaces. And powdery mildew appears in mid-summer as patches of grayish-white powder on leaves and fruit.

So why even bother to plant a tree that succumbs to so many disease problems? Because their ornamental characteristics are outstanding and each year professional horticulturists rate over 700 crabapple cultivars for their resistence to these diseases. There are now a number of improved cultivars with enough disease resistance to look good year round without spraying. Some of the cultivars that show good disease resistance are listed below. Keep an eye out for these as you shop - they generally allow you to enjoy your new ornamental with a minimum of care.

 

1. Adams: A rounded, dense tree with clusters of vivid red buds. Single, 1 ½ inch flowers turn pink with age. The red 5/8 inch fruit hangs on trees through late autumn.
   
2. Donald Wyman: A crabapple rounded in habit and highly resistant to apple scab. It has single white flowers and produces bright red fruits in great abundance.
   
3. Harvest Gold: An upright vase-shaped tree with golden fruit remaining colorful in December and persisting until spring. Flowers are single and white.
   
4. Indian Magic: A rounded tree with rose-red flowers. Fruits are red to orange in autumn, darkening to bronze during the winter.
   
5. Japanese: A broad, rounded tree with dense branches. Flowers are single, pink to white in color and very fragrant. Buds are red.
   
6. Prariefire: New growth on this rounded tree emerges purple-red in color, eventually turning to reddish green. Flowers are a rich, dark, true red.
   
7. Professor Sprenger: A tree with abundant pink buds that open into showy white flowers. The orange-red fruits last until Christmas.
   
8. Robinson: This upright, spreading tree has deep pink flowers and small, long lasting red fruit. Purplish-green new foliage eventually becomes bronze-green.
   
9. Sargentii and or Sargentii ‘Tina’: A dwarf cultivar maturing at 6 feet. This plant bears bright red buds that pen into pure-white, single flowers.
   
10. Snowdrift: Flower buds are pink opening to single white flowers. This tree is symmetrical with numerous, orange-red glossy fruit.
    
11. Sugar Thyme: Pale pink buds open to fragrant single white flowers. The tree reaches 18 feet in height and has long-lasting medium sized red fruit.

For more information visit our web site or call the UNH Cooperative Extention’s Family, Home & Garden Center ’s Info-line (toll free) at 1-877-398-4769. Trained volunteers are available to answer your questions Monday through Friday 9:00am to 2:00 p.m.