Answer #2 ·
Maple Tree's Answer · Hi Ken-The link Josh gave gave you has good information including pictures on how to prune your crape myrtles. Unfortunately if the trunks or stems have grown quite long and spindly you may have to prune them back further than normal to start creating a fuller nicer looking rounded canopy. Crape myrtles are extremely hardy and recover well from any hard pruning that may have to be done. Normally two or more new shoots will emerge from the cut that was made. I also noted a link to a question that was asked awhile back from a member that I believe had the same problem with her crape myrtles as you have. They also were growing very tall without any previous pruning. The answer to this members question shows where Brent Wilson, who is very knowledgeable of crape myrtles, explains where her crape myrtles would best be pruned back to. Just click on this link to go directly to the question and answer. If you would like to upload a picture of your crape myrtles it would help to know the proper pruning they may need. Above this answer and to the right of your name below your question you will see where you can upload any picture you have saved on your computer.
You memtioned some of the trees have many many trunks that are long and spindly. If these trees are being grown as multi-trunk trees it is best to pick 3 to 5 of the most upright strongest trunks for the tree and remove the others at ground level. I would normally prune these small trunks at about 5 feet in height where my canopy would start. Again, seeing a picture would help if you are able to upload one. Any broken limbs or those that you feel may be damaged from winter weather can be pruned back some now but it is best to do any heavy pruning in late winter or early spring before new growth appears. Pruning now in the fall can result in a flush of new growth that can easily be damaged by winters freezing temperatures.
Its unfortunate the trees were not planted in locations beneficial for healthy growth. If the Sweetgum trees are growing to close or over the crape myrtles I would definitely remove one or the other. For a crape myrtle to grow healthy and bloom well they need at least 6 hours of direct sunlight daily. Problems may also arise with competition of the trees root systems for water and nutrients. Too much shade and moisture can cause fungal problems at times with the crape myrtles not having proper sunlight and ventilation as you mentioned. Planting something more appropriate would be determined by which of the two trees you and your neighbors elect to remove, the space you have available for planting trees or shrubs between the trees you are keeping, the amount of sunlight or shade the area recieves, your locations hardiness zone, and a few other considerations. If this is an area you feel would look nice allowing it to return to its natural state possibly removing the crape myrtles would be all that is necessary. If you decide you sill want some flower color in this area you might think about some native flowering shrubs or small trees that might go well with a natural setting such as native azaleas, ninebark, Mountain laurel, Virginia Sweetspire, or others that will survive in your hardiness zone with the sun or shade that will be available. I also noted a link to an article on fertilization as you asked about fertilizing the crape myrtle also.
http://www.gardenality.com/Questions/609/Plants/Trees/How-To-Prune-This-Old-Tall-Crape-Myrtle.html#http://www.gardenality.com/Articles/344/How-To-Info/Pruning/How-To-Prune-A-Crape-Myrtle/default.htmlhttp://www.gardenality.com/Articles/1032/How-To-Info/Fertilizing/How-To-Fertilize-a-Crape-Myrtle-Tree/default.htmlPlease ask if you have any other questions.
John)