When is the best time to prune a myrtle surrounded by Oklahoma?
Answers: If it is up by your house, then within your area I would prune around November or December. Also, when you prune it try and do it at the "tri-points". Basically, you should see where on earth it breaks off into threes. Just above the reciprocal about 3 inches prune respectively of the 3 and try and do it at an angle to prevent rain from sitting on the pruned nouns and causing rot. Also you will probably find that some of the joint don't break into threes, but in two's, prune these alike way, but again try and do them at the 3 point joint if possible.
hope that help, and good luck
ps... If by some destiny your Myrtle is away from your house, try not pruning it at all and the Myrtle will grow much bigger and become a fundamentally strong and well bloomed tree.
prune for size/shape within Feb.. the only time you would prune after bloom is if you're within a warm zone where on earth you can ask the plant for a second round of bloom by pruning off the hoary flowers of the first bloom.. (if you try pruning off the feeble blooms in a cold zone, the plant will try to bloom again, but they will carry killed stale by first frost and that's too big of a stress on the plant). if you do try for the second bloom, you must also feed after the pruning..