Star Thistle: when are the seeds viable?

[poltroon]

I thought I had finally figured out when the seeds were viable for star thistle, but I just read something that worried me, that star thistle actually has two seeds, one that matures early and one that matures late.

Here are the stages of star thistle:

- green plant
- early spines
- yellow flower
- white dandelion-like flower.

It was my understanding that if I got the plants before they had serious yellow flowers, that the seeds would not be viable, and that the ideal time to mow is right when those flowers are starting to emerge. Is that right, or is there a viable seed in the spiny stage?

[fourmares]

I believe that the flowers will mature even after they are cut. The other problem is the root. The stupid plant does not have to re-seed, it just keeps coming back... also once you cut it it will make new flowers just closer to the ground... plan to mow several times. The best thing is to prevent it from getting sun light by having tall grass. It actually lies dorment until the regular grass dies back in summer and once it gets enough sunlight it takes off.... the stuff is truely evil.

[mjrtango93]

How much land are you talking about? We are on 350 acres and surrounding by a good couple thousand of open space so there is TONS of star thistle. The stupid cows don't eat it (really can't blame them there) so we mow alot. For the past couple years though we paid a helicopter pilot to come spray the property with whatever they used and it really kept it at bay. This year no spray as its a rest year, and the crap is everywhere, already on the second mow of the horsie travelled areas. There was a pilot program we were in for this though so didn't pay nearly what it cost as the county picked up part of the tag (Contra Costa County) and the rancher that leases for the cattle rights picked up half of the remainder balance. Perhaps contact your county and see what help they offer. BTY the chemical was non-toxic to the horses, and besides having to be in when the helicopter was flying they were on the pasture by evening turn outs, and the cattle were never moved.

[fourmares]

Apparently Barbados sheep eat it.

[poltroon]

Standard method here is sheep. I am trying to just pull it, but it's a really terrible year for it. Part of my question is disposal. I think I'd better be safe and burn it all.

[Nes]

I spent the last two years pulling the stuff (and two other varieties as well) off our 1/4 acres backyard, it is the bane of my existence!!

Will the sheep really eat it? Because I swear I will go out and get two right now!!!

The method I've employed is hand-weeding (VERY labour intensive) because I didn't want to use pesticides on our lawn. I found a large dose of vinegar at the beginning of spring also did wonders for killing it off (right down to the root). You can also burn it off.

[ambar]

fourmares is right -- the seeds will mature if you cut it and leave it on the ground. :mad:

[fourmares]

I don't know if the sheep will eat it once it has the sharp parts. It's barbados sheep particularly, not just any sheep... barbados sheep are kind of ugly and look like black and tan goats.

[Creaghgal]

Donkeys enjoy thistles as well. Esp. the flowers.

Not sure about Star Thistle.... since we don't get the "pretty" yellow flowered varitiey here in PA.

[poltroon]

fourmares is right -- the seeds will mature if you cut it and leave it on the ground. :mad:

Of course, if I wanted something to grow, that would never work. Sigh.

[Watermark Farm]

The best way to control star thistle is to spray it with Roundup in the early spring, when the plants are just emerging (I think it's called the 'rosette' stage).

Physical removal (cutting and removing) is also good. Lay out a tarp and then carefully cut plants with loppers and use gloves to remove, lay in tarp and haul it all to the dumps. Of course this is only good for small areas. Mowing helps but seems to cast the seeds around.

I hate the stuff, very invasive. I stupidly did not spray for it last year and now 3 plants has turned into a 100x100 patch of it.

[fourmares]

Star Thistle is Round Up resistant... there's something else that you have to use at the rosette stage.

Donkeys don't eat star thistle... and it is toxic to them, just like it is to horses. Totally different than other thistle.

[Roan]

Yellow star thistle at UC Davis: http://cecalaveras.ucdavis.edu/starthistle.htm

Eileen