The manufacturers of glyphosate products will tell you that the stuff needs to sprayed on a plants foliage so cutting down a plant and then spraying is mostly a waste of your time, energy, and money. Some Ragweeds are annuals, some are perennials, so cutting down those that are annuals is enough to control them. Those that are perennials may be a bit more difficult, but for me mowing works just as well.

It's in an area that can't be mowed. They are nested among desirable plants and wildflowers on a 45 degree hill.

I took them all down today by hand with bypass loppers. I was going paint all the cuts with undiluted glyphosate but that was just too much work. Spraying the foliage is problematic due to overspray on nearby desirable plants.

I'll watch and wait to see what happens.

Some things have to be sprayed mature. To protect your other plants use a bucket with the bottom cut out. Put it over the plant then spray inside the bucket. For small plants use something else like a paper towel center, or an old plastic glass, carry out cup, etc..