For those of you wanting a nice flowering tree for full sun exposure, the flowering crabapple is hard to beat, but ONLY if you pick out the best cultivars. There are hundreds of varieties and cultivars of the crabapple, and most of them are actually quite crappy. You read that right–crappy! The inferior selections suffer from three bad foliar diseases (rust, scab and mildew) and some are susceptible to a virtually uncontrollable bacterial disease (fireblight). Too many of them have fruit that is too large for birds to consume, resulting in nasty messes and rotten fruits all over the sidewalk, driveway and patios. Those rotten fruits draw them dang yellow jackets, too. Horrible!
Too many homeowners abuse redbuds and dogwoods by planting them in a hot, sunny location (southwest, west and northwest exposures). Dogwoods abhor hot afternoon sun (3 to 7 PM) while redbuds can handle a bit more, but they won’t thrive with intense PM sun. Instead of planting these “woodland understory” species, plant a crabapple! Some crabs stay nice and small, while others can reach 30 ft tall and wide.
Here’s what you need to do. Visit the nurseries NOW. First, look for trees that still have leaves on them. If the leaves aren’t present, assume they suffered from disease and have dropped off. The owner of the nursery may try to tell you that simple water stress/drought is the reason for a lack of leaves, but don’t buy that line of B-S. Next, look for small fruits—about the size of a pea or just slightly larger. Marble-sized fruits are too big for most songbirds to consume. Finally, inspect the base of the tree for an absence of root suckers. It’s ok to have a sucker or two on the main truck, but NOT from the roots on the top of the root ball. If necessary, try to peel back the burlap on the top of the root ball to ensure that the existing suckers were not pruned of. You can easily feel the woody stubs. Heh now, keep your mind out of the gutter! Rootstock suckers are a symptom of either graft incompatibility or an aggressive rootstock, or both. They will develop all spring and summer long, and thus, make the tree ugly and result in a lot of maintenance headaches for you.