Blue star creeper is indeed invasive and you are not the only one that has allowed this garden tramp to hop into beds uninvited. The most practical solution (other than spraying the entire area with Round Up on a sunny, spring day) is to smother the invader with newspaper and a three to four inch layer of topsoil and then replanting a new lawn on top of the new soil. Fall is the time to layer wet newspaper (5 to 6 pages deep) on top of the groundcover, top this off with heavy, damp topsoil and let the winter rains soak and rot the roots below. Be sure to provide a deep barrier at least six inches in depth between the ground cover and your lawn so it won't creep over again. You can reseed the topsoil or lay sod to create a new weed free lawn in the spring. Now my confession - I also have some blue star creeper that has hopped into my lawn. Luckily a wet winter rotted most of it away but it still pops up late in the summer. I am trying to accept the interloper and admire the tiny blue blooms. Now for your second question, you can prune your weeping cedar by shortening the longest branches and it will not kill the tree but it may not look too attractive. I do not recommend cutting into the main trunk. Try to follow the branches to a joint so you can more easily hide the pruning scars. The trick is to remove some, stand back and look, then remove some more, taking your time to prune to shape. Another idea is to make the bed larger or remove nearby shrubs and plants to give this specimen tree more room to spread out as nature intended. Keep growing, Marianne Binetti