The flowering crab on our front lawn was planted about 10 years ago. It flowered very well until the summers of 2015 and 2106 when it did not flower at all. It is in a fairly sunny location, in clay soil. Other than not flowering, it appears healthy.
Flowering Crabapple best grows in medium moisture, well-drained, acidic loams in full sun. It adapts to a wide range of soils.
As your flowering crabapple is planted on lawn in clay soil perhaps it’s getting too much irrigation and/or nutrition.
A clay soil is usually considered a “rich” soil because it contains large number of colloids and therefore has a high nutrient-holding ability or high cation exchange capacity. A clay soil is low to drain. You can improve the soil structure and drainage through the addition of organic matter.
Lawn fertilizers are usually high in nitrogen. Heavy nitrogen fertilization may delay or retard flowering because nitrogen promotes excessive vegetative growth (green parts), and plant will not flower until rate of leafy growth is reduced.
Weather can also be a factor. An early spring followed by cold weather may mean buds form that later die and flowers will not form. A dry fall may stress trees and deter flowering the following spring.
Some cultivars getting older may also stop flowering every year.
Improper pruning practices can result in a tree with no blooms. It is best to prune this tree as needed in late winter but before new growth begins in the spring. If you prune the dead, damaged and diseased branches and remove crossing branches only, pruning will not prevent your tree from flowering. But if you cut back last year’s growth for size, you are removing all the buds that would produce the current year’s flowers.
Hope your flowering crab will bloom this spring.
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