(cllane’s other half here)
Buttercups, they suck, but I’ve got them down to a science now I think.
#1, like someone said, they are an indicator to a point. The like wet acidic soil, so first, get soil samples done. My results this spring showed very good nutriend levels, but low pH in some areas of the pasture. Ag lime will fix that problem and help the grass outcompete the weeds.
#2, from my days with the USDA Ag Research Service, buttercups to produce a chemical that keeps some plants from growing near them. I don’t remember details, but I remember doing bioassays against grasses with the extracts. Point being, when they get dense enough, they may keep the grass out on their own.
#3, 2,4-D is your friend. I applied by hand, but for a reason. We have a large tractor mounted sprayer, but I wanted to be selective on the first pass. I used a backpack sprayer and ~2 pints of concentrate. The 2,4-D I used was only 2,4-D, it did not have any additional chemicals. If I remember right, the environmental half life of 2,4-D is ~9-10 days, so it is not very persistant. Lucky for me, I have a great entemologist at work that helps me with this stuff.
Most of the broadleaf herbicides are based on 2,4-D but add an extra compound to increase effectiveness. I have 2.5 gallons of Grazon Next that I was going to apply with the tractor to finish up treating the weeds, but… no rain. 2,4-D is ok to apply on pasture w/o grazing restriction when used IAW the label/directions.
to sum it up:
- get soil tested (cheap)
- use 2,4-D
- adjust pH and fertilizer to let grass out compete weeds.
C’mon, how can you resist this face?