diatomaceous earth and vinegar

diatomaceous earth and vinegar

I have a few questions about these things...and thought I'd ask you experienced gardeners what you think...

Diatomaceous earth:
Have you used it before? With what kind of results? How often did you have to apply it?
(I'm hoping to control some ant populations that I suspect are farming aphids around my favorite flowers).

Vinegar:
Same questions as above, but specifically, I'm curious about it's possible success in killing turf instead of weeds. (I'm in the process of de-grassifying my lawn but want to forgo chemicals such as Roundup.) I also wonder how much may leech into the soil and kill desired plants.

Thanks in advance for your expertise and opinions.
Some of my hydrangeas

Some of my hydrangeas

ah, germany

ah, germany

Wall Decoration!

Wall Decoration!

Gardenia with everlasting buds.. :P

Gardenia with everlasting buds.. :P

HUGE caterpillar, what is it?

HUGE caterpillar, what is it?

For what it’s worth…

For what it’s worth…