Any help would be appreciated. I fear that if i let it grow too high and there are seeds/flowrs on it, the wind will blow and it will make the situation much worse.

Thanks.
2.

http://www.yardlover.com/bonide-vine-and-stump-killer-8oz?ctype=2&gclid=CKPrnvP_6qkCFQUb6wodCXHeYQ

and it won’t kill the checkbook.

http://www.yardlover.com/bonide-vine-and-stump-killer-8oz?ctype=2&gclid=CKPrnvP_6qkCFQUb6wodCXHeYQ

I let my thistles get about 2 feet tall, cut them off, and then use an old paintbrush and literally paint it all over them. in about an hour, they wither, and overnight, they turn black and start to die. it was recommended to do this on a moderately warm and sunny day without forecast of rain – apparently, their root systems are most active on a cooler day and it’s most effective then.

have to say it really works. it’s vicious stuff and so satisfying to see them dying back. very few grow where they have died; i was told it may take a couple of applications to really kill the root system.

THANK GOD.

Clean cultivating means removing everything. So I hooked up sweeps to our cultivator, and did the whole half-acre about six times, from May to August. Sweeps work kind of like a hoe, both slicing things below the soil surface and lifting the soil surface to ‘pull’ the plants out. After leaving the field completely bare for four months, I planted the field to winter wheat. The wheat is supposed to provide enough competition to keep the canada thistle at bay for the spring and summer, at least. It may be largely gone from the middle of that field, but it will start creeping in from the edges.

The other organic way to deal with it is to combine a strong smother crop with frequent cutting. Supposedly sudan grass is about the best, since it’s a strongly growing annual. It gets up to 6 feet tall and grows back quickly once it’s cut. We’ll be putting most of the rest of the infested area in sudan grass next spring. Then we’ll be cutting the sudan grass about once a month for the summer. The nice thing about the sudan grass is that it’s providing a good organic mulch while dealing with the canada thistle, as opposed to the clean cultivating, where we’re losing organic matter all summer.

The overall point is that you need to smother the thistle, cut or pull it frequently and persistently, or apply herbicides persistently. You’ll do the most damage to the plant if you can wait until just before it flowers to pull/cut it, but then you risk spreading seeds if you can’t get it cut fast enough. No fun no matter how you cut it.

I have found to my dissmay that glyphosate isn’t 100% effective against such an established infestation, especially when you meausre their height in feet; only ways I know to remove creeping thistle for good, and both are very drastic, is to dig up the area with a JCB and replace the soil or treat the thistle with very harsh chemicals; a mix of sodium hyroxide (lye) and any non-acidic or salt based root absorbed herbicide. It is important to apply this mixture by spray from max effect, on a warm sunny day most surface growth will be dead and brown in an hour. Using concentrated acetic acid in place of the lye is an enviromentally safer opption but both can cause a dangerous soil pH shift in the immediate area, they may also be other side effects depending on what other herbicides are used. The most powerful and easily accessable mixes I found to be is lye and sodium chlorate (not sure on avialability in North America.) Stay away from chlorates unless you don’t want anything to grow in the treated area for a while, also because of its chemistry you cannot use chlorates with acids, hense why I used lye. This stuff is best used on paths and drive ways as it is the atomic bomb when it comes to weed killers.