It would be a lot of work. But if you take a mattock and dig as much of the root as possible, returning to get what comes back up, you would eventually get rid of it. I'm doing this with Great Mullien. It wouldn't be quite as much work as it might seem, in that after you did the initial digging you could go through every other week and just nip those sprouts using a mattock. I bet, in two years, it would be gone.

George
Tahlequah, OK

How often do you mow? I saw a tip on an Extension Office website that suggested mowing only when the plants are flowering but before they make seeds. I don't know if this is feasible for you, but the idea is that if you mow too early in the season, side shoots develop low to the ground. These can grow laterally, eventually producing flowers and seeds that your mower may not be able to cut.

We have a major thistle problem. Doing research I have learned that the seeds may stay dormant for over 10 years. Im in for a long battle to get rid of those. Good luck with your issue.

Round up works well for just about everything. Have you tried any home brew herbicides?? vinager and salt solution?? That might be a better option for you if your against round up.

Poison parsnip is also photo-activated, that is to say, the irritating rash is activated when sunlight hits the juice on your skin. You can pull it after sundown and avoid the rash, by washing up well with soap and water after working in it. You could pull it by hand and put in trash bags...but I realize on two acres it would be a huge job. That, and you would have limited working time in am or pm when the sun is not up. type 'poison parsnip' into a search engine and read up on how else to abate it. If you are going to use roundup, be sure it is listed for that use. Also, be ready with a cover crop to plant so that it will discourage poison parsnip seed in the ground from sprouting and compete with it. Barley or something quick growing for time of year you decide to spray, if you go that way. Just a few suggestions....