Flowering crabapple

Botanical name

Malus species and hybrids (hundreds of cultivars)

Type

Small to medium deciduous ornamental

Size

Small to medium; varies by cultivar (Utah State University)

Hardiness

Zones 3 to 9, so every elevation we serve

Where it is found

Hardy at every elevation we serve, about 4,000 to 7,100 feet

Known weak points

Fire blight, root and trunk suckers, sunscald and frost cracks when young

Crabapples are among the toughest small trees in a Great Basin yard, with hardiness rated to zone 3. They are also one of the trees where an owner is most likely to ask what is killing a branch. This page covers identification, where they grow by elevation, their usual problems and when pruning or removal is right.

How do you identify a flowering crabapple?

In April or May the crown is a cloud of pink, red or white blossoms. Leaves are simple, oval and toothed. After bloom come small apples; Utah State University follows the rule that fruit about 2 inches or less across is a crabapple and larger fruit is an apple. Some cultivars hold the fruit through winter and some are fruitless.

Bark is gray-brown and scaly on older trunks. Look at the base. Thin shoots that spring from the roots or low trunk are suckers, and they are a normal habit of crabapples.

• Spring flowers in pink, red or white
• Small apples under about 2 inches
• Round crown on a short trunk
• Sprouts at the base

Where does it grow in Reno, Carson City and the Carson Valley?

Crabapples are the exception to the valley-floor rule. At zones 3 to 9, they are hardy in Reno (4,505 feet, zone 7b), Carson City (4,680 feet, zone 7a), Minden (4,725 feet, zone 6b) and also in the cold air above them. Utah State rates the group high for alkaline soil and salt tolerance, which fits our ground.

At Incline Village (6,437 feet) and the Nevada south shore towns Glenbrook, Zephyr Cove and Stateline (6,243 to 6,284 feet), the zone 3 rating means cold is not the limit. They are rated shade intolerant, so a crabapple growing in a conifer's shadow will often decline.

What goes wrong with it here?

The most important problem is fire blight. It is listed as a frequent problem of apple and crabapple in University of California and Utah State pest notes. The tips of shoots wilt, turn black and hook over, and dead leaves stay on the twig as if scorched. The Cytospora canker that attacks stressed apples and cherries can also show up as sunken, dead bark.

Young crabapples have thin bark. Colorado State Extension names crabapple among the trees that benefit from a winter wrap because of sunscald and frost cracks, which show on the south or southwest side of the trunk. Fruit drop, aphids and suckers are the nuisance end of the list. Utah State notes that sprouts can be a problem.

Pruning, cabling or removal: which is the right call?

Late winter is the usual pruning time for dormant crabapples, with one exception: fire blight is cut out by following the pest note, with cuts well below the infection and tools cleaned between cuts. Suckers are cut at the base. Our fruit tree pruning guide covers the timing in more detail.

Removal is the answer when blight or canker has girdled the trunk, when a large union has split over a roof or path, or when the trunk is decayed. Crabapples rarely need a crane; most are routine tree removal. Stump grinding deals with the stump and the sprouts that follow.

What does Battle Born Tree Service do about a crabapple?

Start with a free estimate. A certified arborist assesses the tree before any work begins, and the estimate says whether the answer is pruning out dead or diseased wood or removing the tree. Two of our crew are ISA Certified Arborists, and credential WE-11728A belongs to one of them. We do not spray or treat for blight, and we do not plant.