These pretty, purple perennials are resilient and cold-hardy. Mexican petunias are fast-growing plants native to warm parts of South America and Mexico, but they can tolerate cool temperatures in ...

Q: We have Mexican petunias, and all have suffered frost damage. How far should we prune them back? A: Contain Mexican petunia in a localized area, so it doesn’t spread. Cut it back close to the ...

A: A broadleafed weedkiller (containing 2,4-D) will kill a certain portion of them, but at some point, you may just decide to rototill deeply and rake out as much of the root system as you can.