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.

I'll drill a hole and pour concentrated glyphosate for few days. ==>>> thats NOT WHAT HE SAID ... you didnt kill it.. you decapitated it ... interior wood is structure.. not live.. the vital juices of the tree run thru teh cambian layer.. just below the bark ... use the very expensive applicator at the link.. and apply to the outer most quarter inch of a fresh cut trunk ... it should have been done immediately at cutting ... if any suckers appear.. clip with hand shears.. and apply one drip .. until it dies... minimal use.. precise application ... this is NOT a spray.. nor pour thing ken Here is a link that might be useful: link

I've never believed in rose replant disease myself as I often replanted immediately with no problems. But, I was reading in a soil science text last night (I'm writing a master's thesis on soil hydrology) about 'deleterious bacteria' that grow on plant roots. Plant roots are normally coated with microbes of all kinds, but these 'deleterious bacteria' do something that reduces plant growth and their populations can build up over years of monoculture, particularly in orchards where you have the same trees living for decades, and appear to be a cause of yield drops in older orchards and plantations, and a problem for replanting to replace the older trees. So there could be something like this going on with roses that have been in the ground for years and years and are declining in vigor, a buildup of populations of 'deleterious bacteria' that would then attack the replacement rose too. But, I would only be concerned in the case of very old roses that are doing poorly. Not roses being yanked because they get blackspot, or you don't like the color, or they died their first winter, or that kind of thing. Adding organic matter to the planting hole will help avoid the replant problem as it will add more microbes to compete for space on the roots with the 'deleterious bacteria'. I have grown roses for decades, and I often yank and replace right away, and the only times I've had problems with the replacement rose is in the case of soil drainage problems or oak root fungus, common in California and deadly to roses. In your case, I say go for it.

With a tree that small and if I'm sure there are not wires or pipes in the roots, I just take tow strap and a pickup truck and pull it out by the roots. It helps to soften the ground around the tree with watering before you do it. You could have it cut off with a chain saw and then hire a stump grinding service. Their prices vary. I see them advertised for around $100 depending on the size of the tree. If you were thinking about hiring out the whole job of removal, I'd call around, prices vary wildly but make sure it is a reputable outfit that will take responsibility and have proper knowledge about what they're doing.