I use glyphosate(Round Up)but only when I absolutely have to. April

Thanks for the info, JayK!

Small courtyard grass killed by roots from two crepe myrtles & sago palms. Dug out two inches of dirt to replace with crushed limestone (the pretty red kind),several 16" stepping stones & pavers around birdbath. Courtyard is a mass of roots from trees & shrubs. Will cut roots at edge of flowerbed so as not to kill trees & shrubs. What is most effective method of applying Triclopyr to kill roots to prevent problems down the road? Is there something more effective than Triclopyr??

I have no personal knowledge or experience but have read that triclopyr is not as effective when applied to roots. It's absorbed and works better through foliage or fresh stump cuts. "Triclopyr is most effective when applied to actively growing plants." (http://www.hort.uconn.edu/cipwg/art_pubs/GUIDE/consideration.htm)
and
"Triclopyr is absorbed by leaves and roots and is moved throughout the
plant. Lab experiments indicate that foliar uptake is fast with 90% of applied TBEE penetrating vegetation in about 12 hours (McCall and Gavit et al., 1986). Triclopyr can damage plants due to root uptake BUT DOES NOT WORK EFFECTIVELY THAT WAY (Newton et al., 1990)." (www.cdpr.ca.gov/docs/emon/pubs/fatememo/triclopyr.pdf)

You also need to be careful what else is in the formulation. Maybe your state extension agents could give you more information.

I have invasive vinca vines threatening to take over and climb bushes and trees and also running along the dirt. It's like a sci fi movie. I removed as much of it as I could, cutting it down to the ground with a weed eater and pulling away all of the vines, and that's when I could see the woody stems and read about their root system. I read that I could brush Triclopyr on the stems as soon as I cut them and it would kill them. Is this true? Is there a better way?