Crape Myrtles are easy to transplant, and have shallow root systems. Do it soon, though, before the weather warms up, and it'll get along better. First, prep the new location, so you can plunk it straight in. Dig a new hole twice as wide as the rootball you'll be digging up, and about the same depth. Fill in the bottom of the hole with some nice compost, to a level that will put the top of your rootball a couple of inches above ground level. Dig out the beast, taking as big a rootball as you can handle. Transport it to the new hole (dragging it on a tarp is a good way) and set it up in the new hole. Get someone to help by standing back and eyeballing the plant to make sure it's straight up and down, and the best side is exposed. Backfill around the rootball with a mix of the soil that came out of the hole, and more compost. Water it in well. Finally, prune the top to compensate for damage to the roots.

What you described about the multiple branches radiating around the trunk, just below where the trunk has been top cut, is a typical growth pattern for such drastic top pruning. All too often growers have already done such pruning to larger crape myrtles when they are shipped to the retail nurseries. Did your area get the recent days' hard freeze around the Easter holiday? If so the CM in question might have a lot of dead wood which needs to be pruned out. If such a freeze happened, watch the tree as its remaining buds leaf out again. Once the tree appears to be fully leafing out enough to look recovered from any winter or freeze damage; totally remove any trunks or branches which fail to releaf. Also from the trunks nearest your house, completely remove all the way to the trunk any branches in the canopy which you can clearly tell will grow to infringe on your roof. Throughout the following growing seasons feed the tree with slow release quality food, and after every week which fails to provide an inch of rain for the shrub, suppliment the tree with that much water. Over the summer let the tree bloom naturally, and do not prune off the resulting seeds in an effort to extend your bloom season to the first freeze of late fall or early winter. By letting the tree bloom by itself and by being patient if it seems to slow down in bloom presentation after the first bloom flush; the tree will be enabled to put forth effort into thickening its branches and developing its proper rooting perportions. After the tree goes dormant, depending on when temps drop low enough for that, consider the space which any branching from the trunks still invade your roof line. cut, at that time, each trunk, all the way down to the root ball, whose canopy clearly will grow to infringe on your roof line. Hopefully when you have accomplished all the above pruning you will end up with the best of either a one or three main leader trunks. Then, in early march of the next year, prune out again all brittle dead wood, brake off the remaining seed pods and their twigs. Then turn your focus onto any remaining radiating branches which are growing just beneath the previously described, chopped off trunks. Preserve only a flexible and clearly healthy branch which grows the most directly upward and toward the direction where you want the trunk to continue growing. Prune away any other branches which are growing around the trunk near the same level of the healthy upward growing branch you selected to retain. To repeat: the one branch you choose to keep growing off the end of such chopped off trunks should be the one out of the ratiating bunches which appeares to be growing most upright, and growing in the right direction for the retained branch to assume the role of developing into a continuation of the trunk. Hopefully each single branch you select to continue the remaining trunks are thick enough to survive the following winter freezes. If not you will need to wrap each and their tunks with cotton insulator wrap prior to each freeze. If the temps are forecast to drop down to a hard freeze than add bubble wrap around the cotton wrap. Just be sure to remove the plastic bubble wrap any time the temps rise back up above 33 F. degrees. The above advised action takes a lot of dilligent effort, so if you do not think the tree is worth the trouble, simply remove it, grind the stump and main roots and purchase a 10 to 15 gallon sized, 25 to 30 feet potential height grower Crape Myrtle which has not also already been such drastically top pruned-down by the grower. With any such new CM tree you plant in the area, make certain to plant it far enough from the house to prevent roof damage, and to also prune train it properly each year just as you first described above.

I'll bet you added that plastic border fairly recently. Either that or you cut a root while weeding. The baby formed from a severed root of the larger crape. the root system of the baby tree probably mainly radiates out away from the parent tree, so you can keep that in mind when you go to dig it up. I'd try to get at least a foot of root length (based on my guesstimate of size from the picture and assuming root structure similar to what I'd expect in this situation). Crape myrtle root divisions are pretty easy to transplant. Just take your time and get a reasonable amount of root as you remove your baby crape. You may also want to be careful not to cut a lot more of the parent tree's roots in the process of digging up the baby. I'd give this job a rating of easy. P.S. Be careful to get down deep enough to get a good piece of root. Depending on various factors, the bulk of the root system on some of these can be deeper than what you might expect from a seedling of similar size.

You should ALWAYS ask permission! What if you and a thousand other people decide to take cuttings of a particular plant at the restaurant, at the grocery, at the park, dentist's parking lot, Disney Worlld, on municipal property along the road? :-) If it's not yours, you should ask first. Check with your City or County municipal departments. Most have a landscaping division with a director or superintendent in charge. Ask for the manager at the grocery, or the owner of the business. Believe me, if the thought of snitching one or two cuttings has crossed your mind, it has occurred to plenty of others ahead of and behind you. Accumulatively, that constitutes property damage. Right? You simply have to ask; it's the right thing to do. You will either get permission right away or you might get asked to wait until they can take the cuttings for you or they will ask that you don't. Whatever happens, they will appreciate that you asked. I've asked and received permission to take cuttings and seeds from public parks, exotic nurseries, cemeteries, parking lots of businesses, and from the gardens of complete strangers who answered my knock on their doors.