This Tropical Mockingbird was recently spotted in the southern part of Texas. Others have recently been spotted too. That's curious because this is the first sighting of the tropical species in Texas ever. It's normally abundant in northern South America and southern Central America.
Like many of you, we try to garden organically. So we use a safe, low-cost herbicide to kill weeds - vinegar. It doesn't kill or sicken every living thing (including birds) in your yard, and you can buy the ingredients cheaply at almost any grocery store.
I'm certainly no botanist, so I have no idea why it works. But here's how I make it; take one gallon of 10% vinegar (undiluted, from grain alcohol), blended with 1 ounce of citrus oil and one tablespoon of either molasses or plain liquid soap. I just put it in an old spray bottle without adding water, and spray it directly onto unwanted vegetation. (It may need 2 or 3 applications if the plant is particularly deep-rooted)
A word of caution; it works best on actively growing vegetation, so don't expect good results during our superheated weather of July and August, when many plants go into dormancy.