This interesting puzzle came as usual from the Vallejo Farmers' Market.  An older couple came by with questions about a crape myrtle (Lagerstroemia indicia or L. hybrid) that was planted by a landscaping company in their front yard several years ago.  Actually, there are 2 of these bushes/trees planted there and neither one has ever bloomed!  What could possibly be the matter with them and what can be done?

As usual, we started at the beginning: the who, what, where, and how.  As insulting as it sounds, beginning by asking if the plants in question were actually crape myrtles, since plants even in nurseries are mislabeled or put in with other “like looking” plants as this happens –a lot.  This is why it's so important to make sure that any plant you purchase has some form of identification: a stick in the pot, an attached hang tag, or a can label, so that later you can go back to the id and verify you planted the desired plant or tree.  In this instance, there was no id of any sort to be had; on the planting plan, the variety of tree wasn't listed as to variety, just “crape myrtle”.

Then came the “20 questions”:  where are these trees planted, sun or shade, or both; how often are they watered; have they been fertilized and with what; are they in a lawn area or  with grass right up to the trunk; if you pruned them, when and how much; and other questions that occur to the booth members.  Believe me, these questions are very important as to the information we give out.  Without answers, we at the booth can merely be tossing out ideas blindly!  Being told that the trees are in the sun, watered 4 times a week, yes, but with an unknown fertilizer, no lawn or grass, and yes, “he pruned them”, the cloudy crystal ball became just a little clearer.  We suggested less water, no fertilizer for awhile, and no pruning, and sent the couple on their way.

Looking up crape myrtle care in books and Internet, I later found that we were mostly on the right track and a little off at the same time.

Here are some of the mistakes we make with our crape myrtles:

1. Pruning too late. If no flowers appear, it can be because the tree was pruned late in the season, mistakenly removing the new wood which causes the buds for the flowers to never really develop.  Never prune a crape myrtle BEFORE it blooms.  Having said that, just when do crape myrtles bloom?  They usually bloom after other flowering trees and are usually one of the last flowering trees to bloom.  My own crape myrtle just went into bloom last week; I've been admiring others I see in Vacaville and Vallejo for awhile, but this one takes its own time coming into bloom. If you have an older crape myrtle that doesn't bloom the way YOU think it should, wait until after crape myrtle bloom time and encourage it to bloom by PRUNING IT CAREFULLY and LIGHTLY.

If you trim away any dead branches that are inside the tree, this allows more sunshine and air to reach the interior.  Don't just hack away; you can also enhance the look of the tree carefully as you prune.

2. No blooms to lack of sun.  Not enough sunshine will curtail blooms on a crape myrtle.  Being in a place where the tree does not get significant sunshine is a recipe for a non blooming tree. Make sure that the tree is not planted in an under-story position as the shade from larger trees and shrubs will block the needed sunshine to the tree. Full sun is a blooming crape myrtle's best friend.

3. Fertilizer.  If that crape myrtle is getting plenty of sunshine and still not blooming, it could be a lack of phosphorus.  Checking the soil around the tree may prove this out.  OR too much nitrogen may be the problem; both of these situations cause no blooms.  Heavily fertilized flower beds and lawns may have too much nitrogen which promotes leaves but fails to make crape myrtles bloom.  If a lack of phosphorus is the problem, adding bone meal around the tree will add the needed phosphorus over time to the soil.

Checking all of these items should make your crape myrtle and you a happy gardener!