We were gone for quite some time due to a family medical situation. Today I am pulling up thistles that have buds on them. We live in a small city surrounded by farm fields. I would like to get rid of the thistles for good if not this year then next year. I am wondering if any of you have this problem and what you use to eliminate the thistles? I never use to have them in my garden but once they got in it has been a battle.

If you are talking about the mean little things that bloom yellow I have them and they are a pain! I have a big eye dropper bottle with Roundup in it and I drip it on each one. It is a pain to do but it does get them. That and remembering to put down Preen every 3 months seems to do the trick for me.

I tried pulling them out because they do come out easy but within a couple of weeks they come right back. You have to use Roundup on them.

I live out in the country and am plagued with Thistle of all kinds. (along with hundreds of other "weeds")

If I don't catch it real early, I let it get 5" or more, it's ugly, but when you pull it, you get a lot more of the root. I don't think you ever get the entire root, and they grow back, but it's a means of controlling it so it doesn't go to seed. A good deep watering helps with the pulling too.

Not really a solution for a backyard gardener, but I read an article once that said that Thistles regenerates the soil. What is needed when soil lacks fertility is an aggressive plant, one, that grows rapidly and adds organic bulk to the soil and two, deters animals. Let the thistles grow as tall as you then slash them, the thistles lay on the ground as mulch, ready to enrich the soil, not to mention the mass of thistle root material below the surface. This article claimed that areas where the thistle was used as mulch did not have thistle in subsequent years. Apparently, enriched soil is not as likely to grow the beastly stuff.

Another tidbit from my notes on weeds :


Canada Thistle: (Cirsium arvense) Most of you are probably familiar with this noxious, perennial weed. One way to control it is by cutting it down to the ground several times a season. This will eventually starve the thistles tough plant roots and kill it. In large, heavily infested areas planting a smother crop of alfalfa or buckwheat after mowing the thistles has proven to be very effective. Alfalfa is so aggressive in its search for moisture and nutrients it can eradicate thistle. The alfalfa can then be tilled under in late summer to enrich the soil.
One method that can be used in small areas is to inject white vinegar into the center of the thistle. We use a veterinarian type syringe to do this so the solution is in contact only with the target plant. This has worked so well that after several applications the thistle shrivels up, dies, root and all. Vinegar does act as a soil sterilant so you must be careful what it contacts. If you can find 30% acidity vinegar, this is the best to use versus the store brands with about 5% acidity.

Kathy I think I will try the vinegar next year they are the Canadian thistles with purple buds. I got most of them pulled up today will do more later. A friend of mine used some kind of poision to kill them in her garden but I really would rather not use it here yours sounds like a safer solution.

Betty and All,

Apparently there are some precautions you need to take with the higher percentage vinegar too.

That post may sound like I've done it, I haven't just something I copied and pasted for future reference. Make sure you research it more to make sure you are safe.

I still just pull it.

I use roundup on my tough weeds and paint it on with a paint brush, just right on the weed. As far as keeping them out altogether, preen would be the only way I know of. Trying to draw finches to the area may help, they love to eat thistle seeds. But if there are thistles in the surrounding area, there may be nothing you can do but control them in the garden.

When I bought my first daylilies back in the early 90's the promo said that daylily growth habit was so dense, they'd block out any weeds.
Sure enough, the did and I never had to weed.

Then along comes rust where daylilies need more breathing room and that changes the picture.
I don't use Roundup since it has so many bad side effects.
I just weed on a regular basis and use some mulch in larger open areas.

I prefer to try digging thistles from any landscaped bed and herbicides are a fine option as long as you're careful. I like the paintbrush idea, certainly less risk than my spot spraying. I've had thistles get bad enough to warrant digging the entire plant (daylily or other) to remove them. If I had thistle issues right now during the bloom? I'd just snip them off around an inch high and deal with them later.

Enjoy the bloom season knowing your thistles are suffering.

We had so much rain when we were gone that my garden beds are so thick with foliage you would think the weeds wouldn't be able to grow but those thistles just push their way thru. My daylilies aren't blooming yet but they have lots of buds it should be quite a show. I will pull the last of the thistles tomorrow the ones I pulled today really gave me a workout had to squat get a grip with both hands then pull them out using my leg muscles. Wonder if I will be able to stand tomorrow.

I feel for you! That is a lot of work.

2,4-D broadleaf weed killer is an option. In theory, 2,4-D will not kill daylilies. Daylilies are monocots just like grass. Most of the weed&feed products for your grass contain 2,4-D.

When I use 2,4-D (spot spray), I try not to get it on any daylilies, but if I do, it seems ok.

If you are using concentrate, proper dilution is important. A "strong" mixture of 2,4-D will kill everything. I know this from experience.

also, my experience has been that 2,4-D seems to work better on thistle than round-up. And, it's a lot quicker.

We are doing battle with yellow starthistle. Acres of our property were covered in it when we bought the place last year. I agree with Frank that 2,4-D (basically, Weed-B-Gone) seems to work much better than Roundup. With yellow starthistle, timing is everything when it comes to spraying. We hate spraying, but there is no other way for us to get rid of it. Put a huge dent in it, and we'll attack it again later in the year, and again in the spring. It's very easy to pull if the soil is damp, but there is no way to do that on a large scale. Was easy enough to pull in the garden though! Putting Preen down afterwards was a huge help. I've had almost none grow back.

frankrichards16 said:2,4-D broadleaf weed killer is an option. In theory, 2,4-D will not kill daylilies. Daylilies are monocots just like grass. Most of the weed&feed products for your grass contain 2,4-D.

When I use 2,4-D (spot spray), I try not to get it on any daylilies, but if I do, it seems ok.

If you are using concentrate, proper dilution is important. A "strong" mixture of 2,4-D will kill everything. I know this from experience.

also, my experience has been that 2,4-D seems to work better on thistle than round-up. And, it's a lot quicker.

I heard of someone who used it around his daylilies and it killed every one that had been sprayed or had gotten spray on them so be careful around the daylilies if you make a stronger mixture.

I have a commercial herbicide, Lontrel. Very expensive but you use only about 1/2 oz. in a gallon. The thistles start turning brown overnight. Read the label - do not use in food producing areas.

Thanks everyone for all the information. I have most of them pulled up and will finish the rest today, for this year pulling them will have to be the way to go. Next year when they first make an appearance I will try something else. I am wondering if it was the Lontrel someone I know used will have to check with her. Can you use this without harming daylilies?

If they are really big around, use a branch cutter to cut the stalk down then dig up the roots.
Or just keep lopping them off? This would work if they are not perennials and you keep them from reseeding. At least, this is what my farmer husband does with pasture thistles. Now I am curious, are they biennials maybe?

I don't know what they are but I do know that I kept pulling them out and within 2 weeks they were all back again.

You may get some flower distortion if it hits the flowers. Just try to hit the thistles. I had a big patch - sprayed with Lontrel - after they turned brown I put on my leather garden gloves and pulled them.