Spacing on most crapemyrtles should planted 8 to 10 feet apart for optimum future growth and development. Trees should be placed with their future height AND canopy spread in mind. That's difficult for most people to do when they are looking down at very immature specimens.

There are some that are dwarf and semi-dwarf. It might help if you knew what variety you have. I had some that were full sized at 6 feet tall. Nevertheless, they sound too close together. If each is only one or two trunks, you might be able to plant them all together and make one tree. (Most multi-branched crepe myrtles are actually several trees.)

Most that I have seen derive from one primary root system, which is the only acceptable method of growing a multi-trunked tree. The crapemyrtles today, as a general rule, are grafts or rooted cuttings, grown and trained to multi or standards in the nursery of origin.

Michelle, in the future, make sure that the plants you purchase have a 'name' attached to them. ;-) Knowing the cultivar of your plants is all that you need, in order to research its mature size, growing requirements, etc.

Good luck with your crape myrtles!

Very good advice! Unfortunately, I did not buy these; I inherited them when I bought the house. I guess I will be moving them again this fall to spread them out. It is a good thing crepes are tough; this will be the third move in a year.
Michelle