Per the link below... Paniculatas (PG/Limelight types) can be pruned in the fall, winter, or spring. However, it is not necessary to prune them every year. It is suggested that one trim out crossing branches and those that do not contribute to an attractive form whenever necessary. Paniculata hydrangeas are the only hydrangeas that can be pruned into a tree-form. If one is attempting to grow a paniculata as a tree, the developing trunk and main top branches should not be removed. If a panicultata that is trained into a tree-form is cut or broken off close to the ground, it will grow back as a shrub unless the training and pruning is started again from the new shoots. Thanks again, and any other advice is most appreciated! Nothing to add but my Limelight grown as a shrub is big, beautiful, and pretty carefree. I just wish it wasn't located in the middle of a flower bed, since it has gotten so large and there are so many other 'better' locations for it. Sue Here is a link that might be useful: Scroll down for Limelight

I would prefer that it concentrate energies in developing a good root system in its first two or three years. It should speed growth once it becomes established. Water it as needed so it has soil that is moist all the time (or as best as you can). Mulch it well and do not fertilize it until Spring of 2014. Stake it in order to prevent it from toppling during windy/stormy days.

I have my bottle of Roundup out and aimed. I don't think I will just be able to dig it out because it just breaks off and leaves its evil roots, so I will spray the parts I can safely reach.

Flowers - you can remove them at any time for paniculatas like Limelight. However, some people leave them "on" or winter interest. Others cut them when they change from white. Others cut them off when they turn brown. So it is up to you to choose. Nothing is "required". To deadhead flowers, you can cut the little string that connects the bloom to the stem. So cut the string, not the stem. No need at this point to wrap in burlap as Limelight is very winter hardy. You can wait until mid-to-late May to prune all the way down those stems that did not leaf out. Some people do prune it down to -for example- 1' to 18" since it has a habit of growing back a lot from one year to the next. Continue monitoring bent branches to see if they re-orient. If they do not look aesthetically pleasing after a while and the stems are not inclined to self-correct then consider pruning them. Winter would be a good time for this since all the foliage has dried out and you clearly see the stems without the leaves getting in the way.