Bunkey will have to replace a box elder tree next spring. As with most of its kind, it has been a fall pain in the backside. It is a female, thus attracts the box elder bugs that plaster the south side of his light colored house. He suggested painting the house dark green, brown or maroon, but Petunia wouldn’t agree. She likes the combination of cream with aqua trim. “Just get rid of that blasted box elder,” she demanded. Since it shades the east side of the house, it must be replaced. After hitting every nursery and tree farm in western Minnesota, the two of them finally decided on a Kentucky coffee tree.
While, ideally, likes moist rich soil, the tree it a tough one. It will tolerate pollution, drought, high pH and road salt. It will need a bit more water than one usually gives yard trees but is very worth it.
The Kentucky coffee tree is a medium sized tree, excellent size for most yards. It is oval to irregular shaped with an open spreading crown. The leaves are unbelievable. Up to 3 feet long, doubly compound and a bluish green. A nice contrast from our usual common green leaved trees. In late spring it blooms greenish white. The flowers are very attractive to pollinating insects. That fact alone makes it a must have. The blooms are not very fragrant. Nice if you don’t tolerate strong smelling flowers. Only the female tree blooms. Female trees develop 6 to 10 inch flat pods that are quite attractive in the fall as is the deeply furrowed bark. The bare branches are quite architectural. Unfortunately, the pods are a bear to mow so it is best to get a male tree. The fall color is nothing to write home about, but it can occasionally turn a dark yellow.
Since the leaves are so large, one would think the tree would provide dense shade. Actually the shade is filtered or dappled so Petunia can plant grass or shade loving plants under it. It gets its leaves quite late in the spring so it is perfect for a bed of daffodils or tulips either right under it or nearby. And it drops its leaves soon after the first frost so it a good choice where you want sunlight spring and fall. Not only is it disease and insect free, it also has the ability to fix nitrogen in the soil.
This tree is a bit difficult to transplant because of a branching taproot. It is best to plant it in the spring. It is not a fast grower so give it a bit of fertilizer the second year. It will also need watering during dry periods for a few years.
The seed pods have been roasted and used as a bitter, caffeine free coffee substitute, thus the name. However, the raw seeds contain a poisonous acid so keep them away from the kids, or better yet, get a male tree. Look for Stately Manor a seedless male. It is more upright and has a narrower crown; Espresso is another with an upright growth habit and a vase like shape. Prairie Titan is an upright spreading male with interesting winter architecture. All are cultivars developed by the University Of Minnesota. (Our money at work.)