The growths on the trunk are several different kinds of lichen, harmless organisms that actually can indicate decent air quality (they are sensitive to pollutants). Since they don't take any moisture or nutrients from the tree, they do not need removal. (Attempting to scrape them off might actually damage the bark, which is fairly thin on crapemyrtles.) As the plants mature, crapemyrtles normally shed their outermost layers of bark, so as this tree ages the lichen numbers will probably decrease because of this phenomenon -- they can't attach as well to flaking or peeling bark.

We can't tell if this is one of the dark-leaved cultivars of crapemyrtle, whose foliage normally looks nearly black, or if the leaves are covered in a dark coating. If the latter, this would be sooty mold, and its presence indicates a population of sap-sucking insects like Crapemyrtle Aphid or Crapemyrtle Bark Scale. You can use the information on the linked pages to look for each pest, and feel free to send us close-up images of the bark or leaf surfaces (both upper and lower) if you aren't sure if either is present.

Miri

Miri,

You're welcome.

Lack of blooms could be due to several factors, possibly in combination, including: the timing of pruning; insect pest outbreaks; powdery mildew infecting the developing flower buds or young growth; over-fertilization (they don't need any fertilizer, but could be absorbing what is applied to the lawn); drought stress; and the reduction in energy production from recurring bouts with sooty mold (which blocks some of the light reaching the leaves).

Resolution of the suspected pest outbreak should help (though maybe not in time for any blooms this year) and you can monitor the plant's root zone for watering needs. Feel the soil around six inches deep and water well when it's getting fairly dry to the touch at that depth. As a very rough guideline, during hot summer dry spells, watering might be needed once every week or two, depending on soil type and other conditions.

Miri