So I've been slowing pushing back on some poison ivy on my property using Round Up Poison Ivy Plus Tough Brush Killer. I normally try to go in two times a year, once in the spring and once in the summer and spray whatever I see growing. All the big growth seems dead now and I'm basically working on small shoots that I miss each time. This year I've been a bit behind the times and just am getting around to it. Will it be effective to spray poison ivy in the fall? Or should I just wait until next spring. The leaves on these plants are starting to orange. (I'm in New Hampshire and its October if that matters) This is what the website says but I'm not sure if they are still growing around now:
WHEN TO APPLY Apply when weeds are actively growing. For best results, apply during warm, sunny weather (above 60�). Spray when air is calm to prevent product from drifting onto desirable plants. Rain or watering within 30 minutes of application will NOT wash away effectiveness.
Also as a side question in a few years I plan on cutting down the other brush in the area and converting it to grass. How long do the vines from poison ivy need to dead before I don't need to worry about getting the rash from them?