hi. we moved down the hill from my parents last year. lots of disturbed soil and thistles. did not get ahead of them in the summer.read an article on canada thistle in ab agriculture "Bye Bye Canada Thistle"

The author suggested disturbed and poor soil was the reason for thistle invasion. His solution included chopping, mulching and manuring and rototilling thistles for about three years and the things were gone and have remained gone. My question is should I try this?

I have a big bed (400 feet long by 20 feet wide along driveway) with some transplanted things: yarrow, lilac, daisy etc it is both very clay and thistle and grass infested.

Would 20 year old manure do the trick? should I rototill first and kill the roots with burning or rototill and leave roots buried by manure? Should I lay manure?

My mum thinks manure will just make them grow 10 feet instead of this years' 5 feet tall.She thinks I just need to pull them. I avoided pulling all summer, thinking everyone I would pull would leave 900 viable plants underground just waiting to pop up. However, I have since started pulling.

I am feeling overwhelmed cuz I have 6 acres and 2 little kids, we are building a garage and live where the snow flies.

I don't know necessarily what I should do or even do first (needless to say there are other areas needing attention, but so far this bed has had the most time invested)

I have also covered other areas with poly hoping to kill the grass underneath and buy myself time till next year. This may work,but there are already a lot of plants there that I would have to avoid and the poor soil issue still remains.

Any ideas how, when what order etc would be great

Thanks Nance outside of Calgary

I agree with your mum that using manure will just get you bigger and stronger thistles. And will more likely burn your desired plants before it puts a dent in a tough customer like the Canada thistle.

I think pulling and rototilling will also just make things worse, as these suckers spread by both seed and root, and the smallest bit of root will resprout. Also don't allow the existing plants to set seed. According to the literature, the seed will remain viable in the soil for up to 20 years.

My suggestion would be to move the plants you want out to a holding bed and solarize the bed with the thistle under a heavy layer of black plastic, starting in the spring. Let it cook for a couple of months, then take off the plastic, ammend your soil and replant. Lastly put down a good thick layer of mulch over the soil, to suppress germination of seeds that remain in the soil. Keep grubbing out any new seedings you find.

Here's a website with more information on this lousy weed: http://ianrpubs.unl.edu/weeds/g509.htm

I try not to use Roundup unless I have to, but my nemesis, unvariegated goutweed, has been too difficult to deal with otherwise. I try to minimize the amount I use and protect the plants I want to keep by using a small paintbrush to put the Roundup directly on the goutweed leaves. Even our local native plant society (as big a group of environmentalists as you get) will use Roundup in this manner to reclaim areas from the invasives, if there are no other options.

You have a big job ahead of you! Good luck!!

Thistles The bain of my back yard. (i too have fought these pesky ... beautifull devils!) (remeber finches love them) i PULLED & PULLED & PULLED & PULLED!!!! ) manure will just give the beggers more help.... dig em up now while they are small. (Believe it or not i used Urea on the hot spots ...... killed them dead .... (Sounds weird i know but it works) round up is wonderfull but with small children around i'd be hesitant to use it (I too have kids)

In the early spring, I walk around with a dandelion puller and get rid of thistles by yanking them up. I hate to accidentally step on them mid-summer while barefoot! I leave one or two at the very back of the property, for the finches.

One way to help keep thistles under control, if you have children is to put a bounty on their heads (the thistles, not the children). I started at 25cents per thistle (must have roots attached), but quickly had to reduce the price as my kids and their friends were going to bankrupt me.