Spring and fall are the preferred times for planting nearly all trees. But crape myrtles are an exception. Their roots actually grow rapidly in warm soils, which means now is a great time to plant. Just make sure to water well throughout the summer months.

The greatest thing about crape myrtles these days, as opposed to just a decade or so ago, is that there are so many sizes available, from less than two-footers to over 20-footers, and just about everything in between. And in addition to the familiar tree forms, there are some awesome shrub forms as well. In other words, there’s a spot somewhere in your garden for a crape myrtle, assuming it gets plenty of sun.

Leaf colors are now available in green to reddish to purple to almost black, and although the basic flower colors haven’t changed all that much, the range of hues certainly has. Particularly striking are the varieties with nearly black leaves and white flowers selections. 

Crape myrtles will grow in decent soil so long as it drains well, but they don’t like wet feet. More than anything else, they need sun, and lots of it. They simply won’t grow well -- and more importantly, won’t flower well -- if grown in shade. 

In late winter, remove branches smaller than the diameter of a pencil, especially those in the interior of the tree, to promote good air circulation. Do not cut them back hard (even though you may see others doing just that), because it destroys the plant's natural form and creates ugly knots or knobs. Pruning suckers that form at the base of the trunks improves the look of the tree.

This black, sooty fungus is caused by insects, including aphids, whiteflies, and scale (see below). So if you get rid of the insects -- which primarily attack leaves -- you get rid of the mold.
Spray leaf surfaces with insecticidal soap, horticultural oil, neem oil, or spinosad and the problem should go away fairly quickly.

The second best way to prevent powdery mildew (which, by the way, is a fungus that looks just like it sounds), is to make sure plants have sufficient light and air circulation. The best way is to simply plant a resistant variety, particularly those with distinctly Native American names -- Arapaho, Comanche, Natchez, Sioux, for example -- as well as Dynamite, Red Rocket, and Pink Velour. Infected plants can be sprayed with horticultural oil.

Bark scale is nasty. And ugly. The white to gray, felt-like scale insect responsible for the condition secretes honeydew, which then encourages the development of black sooty mold on branches and foliage. OSU continues to recommend scrubbing affected areas with mild dishwashing soap and water (a stiff nylon brush works well), followed by an application of horticultural oil or neem oil to smother any remaining adult insects and their eggs.