I believe if you water it normally and mow high, St Augustine will march through and take over almost every grassy plant with the exception of some weeds which have slightly coarser blades and also grow tall. Crabgrass can get a hold and hang on toe to toe, but bermuda and other fine bladed grasses seem to have absolutely no chance against St Aug. Here are two pictures of my current back yard. I have not purchased any St Augustine. At first there was a thin line of it surviving against the concrete patio. I nurtured it along and you can see the results after 5 years. 2014 2019 The St Augustine stops at the line about half way between the dog and the bottom of the picture. I mow the weeds low and the St Aug high, so the line is fairly clear. This year it is down to the bottom of the picture and still spreading. The original "lawn" was a mix of dormant bermuda and prairie grasses like buffalo and the ubiquitous King Ranch bluestem.

For newcomers this site is actually pretty hard to navigate, edit, post and upload pictures. But since we are on the topic of Velvet Leaf and in light of the toilet paper madness because of covid19, I just gotta say.... If we ever DO have to worry about toilet paper shortages... (which is NOT at this time btw) I would just forage around for this plant! The leaves make an acceptable wipe (or so I heard).

From what I understand, zoysia is just a fancy bermuda grass. goodbye gardens and flower beds! there is a chemical now thats supposed to kill it, but roundup wont touch it. good luck, i've battled bermuda for 40 years--its winning.

All that fluffy stuff is seeding new plants everywhere. Doesn't much matter what it is. Pull & discard before it seeds.