How to Grow and Care for Weeping Crabapple

The weeping crabapples comprise a subgroup of the crabapple group, which is itself a subgroup of the much larger Malus genus that includes all apple trees. Crabapples are usually grown for their lovely spring flowers rather than fruit, and those within the weeping group are known for downward-turning, cascading branches that display beautiful white or pink blossoms each spring. The bloom season is short-lived, often lasting just a few days up to two weeks. However, the lush, green foliage and small red, yellow, or orange fruits that the tree produces provide visual interest into the fall and even into winter.

As with other flowering crabapples, the fruit of a weeping crabapple tree is largely ornamental—less than 1/2 inch in diameter and too sour to be edible except perhaps when used in jellies. Weeping crabs are usually planted as potted nursery specimens or ball-and-burlap plants in the fall. They are generally smaller and slower-growing than standard crabapples, growing only about 6 inches per year, and it may take several years before they reach flowering maturity.

As is true of all apples, the fruit of weeping crabapples has seeds containing small amounts of amygdalin, which breaks down into a toxin. But because crabapples are sour and not very tasty, there's not much likelihood that the seeds will be eaten in dangerous amounts. Moreover, the seeds would need to be pulverized through chewing in order to release any toxins, which is unlikely.

Weeping Crabapple Care

Growing a weeping crabapple is easy enough for beginning landscapers and beautiful enough to make a worthy addition to any yard or garden. These trees are hardy enough to produce blooms even in cold weather climates that other flowering trees—like magnolia and dogwood—can't survive. Weeping crabapples require only basic care and attention. They’re fairly drought-resistant once established, and often don’t need any additional watering other than rainfall unless drought persists. The weeping canopy of the tree generally doesn’t need pruning, unless you have a specific shape in mind. If so, prune outside of the growing season to avoid damaging the tree or reducing its resistance to disease.

These fruit-producing trees will drop crabapples in the fall and early winter. The decaying flesh of the fruit may stain driveways, sidewalks, and patios, so keep this in mind when choosing where to plant your weeping crabapple.

Light

For maximum flower and fruit production, a weeping crabapple demands full sun. Ideally, this tree should receive eight to 12 hours of direct light each day. However, if you have a spot that is partly shady, the tree can tolerate such conditions—but it will probably produce fewer blossoms and fruit.

Soil

The crabapple tree is not fussy about the type of soil it’s planted in—as long as it’s well-draining. Otherwise, the roots of the tree can become soggy and subject to rot. Soil should be friable for the health and longevity of the tree. In addition, these trees do best in soil with a pH level of 5.0 to 6.5; slightly acidic is best. 

Water

Once established, rainfall generally produces sufficient amounts of water for the crabapple tree. These trees are considered to be drought-tolerant, and therefore a good choice even if rainfall can be spotty. However, you should plan to supplement this tree with additional watering if drought stretches on for an extended period. Otherwise, the tree is likely to deplete its energy reserves to maintain vitality, resulting a shortage of blossoms and fruit in the following year. 

Temperature and Humidity

Weeping crabapple trees are rather hardy and make a great ornamental choice even in colder weather climates. They’re generally considered hardy to USDA zone 4. At the other end of the spectrum, these trees can handle the heat and humidity up to zone 8—or sometimes even into zone 9, depending on specific growing conditions.

Fertilizer

Generally speaking, these trees should grow 5 to 6 incher per year until maturity. If your tree is growing more slowly than this, it may be a soil nutrient deficiency that indicates that fertilizing is warranted. Perform a soil test before applying any fertilizer to determine what the nutrient deficiency is, if any. For soils lacking in general nutrients, you can often use organic fertilizer that is spread around the tree, over top of the root system. This should be done in the fall and again in the early spring before the growing season commences.

For soils with a serious deficiency in nitrogen, chemical (non-organic) fertilizers might be the best option for a quick change in soil nutrients. However, too much nitrogen can weaken the tree’s defense against disease, so be careful about how much and how often you add chemical fertilizer. 

Types of Weeping Crabapple

• Malus ‘Louisa’: One of the most popular types of weeping crabapple trees is the Malus ‘Louisa.’ This cultivar grows about 10 feet tall and has graceful, long limbs, accented by pink blossoms in the spring, rich green foliage in the summer, and small yellow crabapples in the autumn.
• Malus ‘Royal Beauty’: This weeping crabapple is unique for its purple foliage and deep red crabapples. These trees reach a mature height of about 10 feet and are typically taller than they are wide—though they do broaden with age. This type produces fruit late into the season.
• Malus ‘Red Jade’: With a spread of about 15 feet, ‘Red Jade’ has a beautiful canopy with long branches. Springtime brings pink flower blossoms that open to reveal white flowers. The fruit of ‘Red Jade’ is a bright, cherry red color and enjoys a long season, remaining on the tree into early winter.
• Malus 'Red Bud' (Malus x zumi var. calocarpa) : This is a 10- to 20-foot variety with white flowers and branches that cascade at the tips. The fruit is bright red, and the leaves turn an attractive shade of golden yellow in the fall.
• Malus 'Molten Lava' ('Molazam'): This 12-foot high tree blooms with profuse white flowers in early spring. It has excellent resistance to disease.

Pruning

In most cases, the weeping crabapple tree will grow into a beautiful, downward-facing crown without much pruning or interference. However, if you do feel the need to shape your tree or it becomes necessary to trim it back, then you should plan to prune it during a time of dormancy.

Generally, the best time to prune is in late winter (after the coldest weather has passed) or early spring before the growing season begins. If you prune the tree as it begins the growing season, you risk hindering the flower and fruit development for next season. 

Propagating Weeping Crabapple

Most named crabapple cultivars are grafted trees that are created by grafting branches from ornamental varieties onto the hardier rootstock of native species. Therefore, there is no way to propagate most crabapple trees by traditional vegetative or seed-starting methods—at least not if you want a plant guaranteed to have the same performance and hardiness as the parent tree. But you can certainly try to propagate your weeping crabapple by branch cuttings, with the understanding that the results will be unpredictable:

1. Early in the growing season, clip 8- to 12-inch cuttings from flexible green growth at the tip of the tree's branches, using sharp pruners.
2. After stripping off the lower leaves, scrape off the bark on the bottom few inches of the cuttings.
3. Dip the stripped end of each cutting in rooting hormone, then it in a pot filled with moist, coarse sand.
4. Place the planted cutting in a plastic bag, then set the pot in a sunny location. Keep the pot moist until roots form—about four weeks. Check frequently and moisten the pot when necessary.
5. When a good network of roots has developed, remove the plastic bag and continue growing the cutting in full sunlight. In a few weeks, transplant the sapling into a larger container filled with commercial potting soil.
6. Continue growing the tree in the pot until it is sizable enough to transplant into the garden. It's typical to plant in the fall after starting the cutting in spring.

How to Grow Weeping Crabapple From Seed

Weeping crabapple cultivars are usually grafted plants, so new plants started from their seeds generally don't produce trees with the same performance or appearance as the parent tree. But if you want to try it, you can harvest some seeds from fall fruit, store them through the winter, and start them indoors in late winter.

Plant the seeds in small pots filled with a mixture of commercial potting soil, peat moss, and perlite or vermiculite. Barely cover the seeds with potting mix, then lightly water and place the pot inside a plastic bag in a bright, warm location. After the seeds sprout, remove the plastic cover and continue growing the seedlings in a sunny location. When the seedlings are about 6 inches tall, they can be transplanted into larger containers filled with standard potting mix. When the seedlings reach a height of 12 inches or so, they can be planted in the garden. This may take a full year of growth in the pot before they achieve a suitable size.

Potting and Repotting Weeping Crabapple

Although it's not common, smaller cultivars of weeping crabapple trees can be grown in large containers. The pot should be at least 24 inches in diameter, and rather than commercial potting soil, fill the container with a mixture of garden soil and compost. It's best to use a cultivar that grows no more than 10 to 12 feet tall, and you should be prepared to prune it regularly to keep it from becoming too top-heavy for the pot. Crabapple trees are difficult to repot, so use the largest container you can. Potted trees can be more susceptible to winter cold, so you may need to move it into a sheltered position for the winter.

Overwintering

It's a good idea to guard the trunks of young trees with metal hardware cloth or fencing during the first two or three years to prevent them from damage from gnawing animals. And it will help to also wrap these young trees with tree wrap to protect the bark from winter burn.

As winter approaches, rake the ground beneath the tree clean of leaf and fruit debris to prevent insects and diseases from overwintering.

Common Pests & Plant Diseases

Weeping crabapple trees are subject to many of the same disease and pest issues as other crabapple and standard apple trees:

• Fireblight  caused by the Erwinia amylovora bacterium creates oozing wounds in the tree's bark and blackened, burned-looking leaves. There is no cure, but good sanitation will prevent the spread of the disease. Avoid fertilizing with high-nitrogen fertilizers, which can encourage the bacteria.
• Rust can be caused by several different fungi, creating orange-yellow spots on the leaves. There is usually no need to treat mild disease but fungicides can be used on severely diseased trees.
• Apple scab is another fungal disease. It causes olive-black spots on the leaves and fruit. Properly timed application of fungicide can also help treat the disease.
• Powdery mildew is a fungal disease that coats leaves with grayish-white powder. Regular pruning to improve air circulation often helps prevent powdery mildew.

The most common insect pests include aphids and mites, both of which cause deformed leaves and both of which can be treated with horticultural oils, such as neem oil.

• Japanese beetles chew holes between the veins of leaves. Unless the infestation is very severe, it's best to ignore Japanese beetles rather than spraying with insecticides.
• Appletree borer attacks young or sickly trees, boring into the trunk and main branches, often causing cracks. There is no control, other than keeping your tree healthy so it can fight off the damage.

How to Get Weeping Crabapple to Bloom

If your young weeping crabapple doesn't bloom, you may just need to be patient. A young tree typically takes three or four years before it is mature enough to bloom and produce fruit.

Also make sure the tree's cultural needs are met: plenty of sun and regular water. And make sure to prune on the proper schedule—during dormancy, not during the active growing season.

Common Problems With Weeping Crabapple

Weeping crabs are usually easier to care for than standard crabapples since a slightly unkempt, cascading growth habit is desirable. But these trees can be prone to some common complaints:

Cracked, Oozing Bark

Badly damaged bark may indicate that the tree has been infected with fireblight or is facing apple borer infestation. If you see these symptoms, it's wise to consult a professional for diagnosis and treatment recommendations.

Wasps Swarm Around Tree

All crabapples are an attractive source of nutritional juices for yellow jackets and other wasps who seek out decaying fruit in the fall. As your tree begins to shed fruit, keep the ground free of debris.