Bull thistles

[redman135]

Bull thistle, aka scotch thistle, is easy to get rid of if you have cattle. On a fine day bruise the leaves(use a harrow, or drag something over the thistles) this causes the leaves to wilt and the catttle will do the rest. The cattle won't eat unbruised thistles. Best results are obtained by bruising at the leafy stage and the cattle will eat the thistle off at ground level.
You can mow, but you must mow BEFORE the seed heads form. Expect to mow at least twice.

Canada thistle, aka californian thistle, requires different tactics (it sprouts from subteranean roots). Wait until the flowers are at the " hardball" stage,(flower head has formed but NOT flowered) then hit with roundup using a weed wiper(zwiper) or roller type wiper (roto wiper) if you want to save the grass, or blanket spray if you are culivating. NOTE the timing is critical to achieve a good kill. Also, take a before and after picture. Timed right, the callies will be exterminated.

 

[redman135]

oosik, with Bull / scotch thistle, the growing point is above the ground, so you only need to cut the top off and NOT leave any leaf. If you look closely at the stump and it has a cup shaped depression in it then you have removed the growing point and that thistle is dead.

 

[redman135]

If anyone has mystery infestations that just appear, did you feed hay there? Hay is a common source of thistle spread.

 

[oosik]

We get winds in the late fall. At times I've seen "white clouds" blowing in the wind. Great "pods" of thistle seeds. The ranchers on both side have thousands of acres of open range land. They can't be bothered with the spreading of thistles.

 

[ponytug]

If anyone has mystery infestations that just appear, did you feed hay there? Hay is a common source of thistle spread.

It is a nice idea.

Around here there is enough around on other properties to spread via wind. It doesn't correlate with our hay feeding, but I have no idea how long the seeds are viable in the soil here. For all that I know, the seeds come from 30 years ago.

To your prior comment on mowing/harrowing; it is what I do. I mow when it is in full growth, but no seed heads, and the cattle love the green "silage", and yes, I usually have to mow it twice here. Both times are always a bit hair raising due to our slopes, and the slick nature of thistle sap...but it is effective. I'm thinking of trying @oosik's method for any stragglers or in lieu of the second mow next year.

All the best,

Peter

 

[oosik]

I periodically travel on the ATV both North and South. Open range lands owned by two rancher. I seldom see much thistle on either property. Could be that the cattle will eat them. I know the deer really enjoy the seed heads of our milk weed.

Around here the thistle grows quite a bit taller than all the other grasses and weed. Pretty easy to spot.

 

[MAX-24-Dean]

We get winds in the late fall. At times I've seen "white clouds" blowing in the wind. Great "pods" of thistle seeds. The ranchers on both side have thousands of acres of open range land. They can't be bothered with the spreading of thistles.

Last year I thought the cottonwoods were blowing it was so white out the front window. Until I noticed the umbrella shape of the thistle blowing towards the house. I've cut 6 12 gallon bags of the flower tops off of the thistle and pulled them after cutting the tops.
Then find out they spread by there root system! Well I guess I might have to spray them to get rid of them.

 

[MAX-24-Dean]

Bull thistle, aka scotch thistle, is easy to get rid of if you have cattle. On a fine day bruise the leaves(use a harrow, or drag something over the thistles) this causes the leaves to wilt and the catttle will do the rest. The cattle won't eat unbruised thistles. Best results are obtained by bruising at the leafy stage and the cattle will eat the thistle off at ground level.
You can mow, but you must mow BEFORE the seed heads form. Expect to mow at least twice.

Canada thistle, aka californian thistle, requires different tactics (it sprouts from subteranean roots). Wait until the flowers are at the " hardball" stage,(flower head has formed but NOT flowered) then hit with roundup using a weed wiper(zwiper) or roller type wiper (roto wiper) if you want to save the grass, or blanket spray if you are culivating. NOTE the timing is critical to achieve a good kill. Also, take a before and after picture. Timed right, the callies will be exterminated.

oosik, with Bull / scotch thistle, the growing point is above the ground, so you only need to cut the top off and NOT leave any leaf. If you look closely at the stump and it has a cup shaped depression in it then you have removed the growing point and that thistle is dead.

Thank you for the information redman135.

 

[TugBarge]

Around here there is enough around on other properties to spread via wind. It doesn't correlate with our hay feeding, but I have no idea how long the seeds are viable in the soil here. For all that I know, the seeds come from 30 years ago.

A farmer in Western WA once told me the local agricultural extension was suggesting thistle seeds are viable for up to 30 ish years, depending on soil conditions.

 

[TugBarge]

If anyone has mystery infestations that just appear, did you feed hay there? Hay is a common source of thistle spread.

Definitely get more thistle spread when feeding round bales without an elevated feeder - I have wondered if it's the seed in the hay OR the choking out of competitive grasses that actually causes the spread.