Every time I'm asked about tree selection, there seems to be one common theme: "What is the perfect tree?"
While I've never found a Shangri-La where all trees are perfect, I must admit that some of the new varieties of crab apples are exceptional.
Some time ago I heard several national experts discuss crab apples and their advantages and disadvantages. They shared an interesting perspective (one with which I agree) about choosing the perfect tree.
These experts pointed out that the overwhelming reason people selected crab apple trees was the bloom. Yet they also noted that the bloom is only on the tree for a maximum of two to three weeks each year. That means it is essential that you look at other tree characteristics when making a selection.
Remember, a tree is not like an actor who runs on and off the stage. It is more like the theater itself, as trees are in the landscape year-round. Trees must be chosen carefully to take full advantage of their best year-round characteristics.
Few trees have undergone such radical transformations in such a short period of time as the crab apple. These trees used to be planted strictly for their fruit, not as ornamentals. But as interest in ornamentals increased, many crab apple varieties fell out of favor because people didn't want to deal with the fruit.
Interestingly enough, crab apples have enjoyed a resurgence in the orchard, not as fruit producers but as pollinators. It is as ornamental plants that they have enjoyed their stunning popularity.
Few trees create more interest or visual impact during all four seasons than flowering crab apples. In the spring they take center stage as all eyes turn to their flowers. The emerging buds often hint at one color and open to reveal another. The flowers show anytime from mid-April to May, depending on the season and the cultivar.
Blossom colors range from snowy white to delicate pinks to deep reds and even hints of lavender. Some cultivars have coral- or salmon-colored flowers, and some have stunning combinations of several colors.
Further interest comes from varying flower types. Flowers are classified as single (five petals), semidouble(six to 10 petals) or double (more than 10 petals). Double-flowering crab apples retain their flowers longer than other types, and these double-flowered types have fewer fruits.
Leaves are the summer features. While many, as expected, have green leaves, some have darker green-, red- or burgundy-colored leaves. As summer gives way to fall, the second showiest season emerges. Both the foliage and the fruit are transformed into striking color combinations that offer an unparalleled beauty.
As the leaves fall, the fruit still remains on many varieties. These fruits often hang on until later in the winter, with the bright colors contrasting with the snow. Even in late winter, the snow accents the branches and the tree form. These trees are rightly crowned with the title "jewels of the landscape."
Crab apples have diverse growth habits and shapes. The shapes consist of weeping (pendulous), rounded, spreading (horizontal), upright (columnar), vase-shaped and pyramidal.
Lest they sound too good to be true, I am compelled to point out a few drawbacks. Among the most serious is their susceptibility to diseases. No matter how wonderful the flowers are on a tree, the tree is not on the keeper list if the diseases are too serious. Keep that in mind while making your decision. You must look for a cultivar that is suitable for Utah conditions.
Pay the most attention to how susceptible the cultivar is to powdery mildew, as this is a severe and widespread problem in our area. While you can spray for the disease, it is costly and time consuming.
Fire blight is a serious problem on some cultivars. Select resistant varieties, and avoid pruning trees in the spring, when infections are likely to occur.
Crab apples are likely the most serious problem a homeowner will face, so choose varieties carefully. Many older cultivars produce bushels of fruit, turning the trees into horrible maintenance problems. Select fruitless trees that have flowers but not the messy fruits.
The fruits stay on the persistent varieties until the birds eat them in the winter. Unfortunately, these trees have a tendency to develop root and collar rot and should be placed in well-drained soil.
Many varieties are extremely cold hardy, and their growth habits and size are excellent for areas under power lines, as small accent trees and for small parking strip trees.
Larry Sagers is the regional horticulturist at Utah State University Extension Service at Thanksgiving Point.