Saturday, March 31, 2012

Another bad invasive: Malta star-thistle

Malta star-thistle (Centaurea melitensis)
Similar species is yellow starthistle (Centaurea solstitialis)

Here recently, I must admit that I felt a little relieved to know that we don't have the bastard cabbage (Rapistrum rugosum) in our neighborhood. Then last Wednesday, I met Ricky Linex, a wildlife biologist with the Natural Resources Conservation Service, at a Riparian Workshop (part of my Texas Master Naturalist training). On a creek bank near Horseshoe Bay, he pulled up a dark green plant and said it was the invasive thistle he mentioned to me earlier.

Malta star-thistle (Centaurea melitensis). It's just as bad as bastard cabbage.


In the meantime, James and I had been eyeing a healthy crop of big green plants growing along the street that adjoins the Meadow. Uh oh.

After I got home, I took a closer look at the plants.


We've got Malta star-thistle IN OUR WILDSCAPE!!

Yesterday evening, James started pulling it up. I pulled up more around noon today and walked across the street, too, to yank up some growing in our neighbor's yard. We've got a LOT more to pull. And there's more young ones coming up.



Just now, I reported our thistle to Early Detection & Distribution Mapping System, a web-based mapping system for documenting invasive species distribution. My Record ID for the Malta star-thistle is 2027636. 


Here we go after supper, back to work on the Malta star-thistle. Bad stuff! Last year, the city scraped this side of the street for sewage work, and then left it be. We should have tried to reseed it, I guess. At any rate, this thistle showed up in full force.
It took everything I had to pull up some of the thistle!!! I think it should have a similar name as that bastard cabbage....

Daunting work, but we kept at it.

I asked James to take a photo of what's UNDER a cluster of thistle. NOTHING.

James won the prize for the biggest thistle of the evening.

We removed the majority of the Malta star-thistle...for now. We'll have to keep pulling until hopefully we win and not the thistle. 

* * * *

More info on invasives:

National Invasive Species Information Center

Invasive Species, AgriLife Extension, Prairie View A&M University


I asked Ricky some questions about best how to control the species:

"There are chemical methods, but the plants might still produce seed because of the length of time required for the chemical to work. Hoeing or pulling will get roots and all. According to a forest service pub mowing and I suppose weed-eating can cause the plant to send out side branches. Google "Field Guide for Managing Malta Star-thistle" to read more."

Can the piled up bunches of pulled thistle still make seeds?

"If it hasn't produced yellow flowers, it won't now make seed. The ones you've pulled were caught early so they are done. And forgot to add that the untouched plants will bloom different heads through early summer."

UPDATE, MAY 12, 2012

I am still pulling Malta star-thistle and beggar's ticks (Torillis arvensis), another non-native. The species is also called hedge parsley. You've seen the has pretty white flowers that resemble baby's breath or Queen Anne's lace. Then the flowers turn into nasty burrs that stick to socks and fur. As I was yanking the plants, I noticed that the species--like most invasive weeds--crowds out everything and creates a monoculture (nothing grows under it)!

My pile of thistle and beggar's ticks.


Anonymous said...

I am a Noxious Weed Specialist in New Mexico. Malta Starthistle is one of the weeds that has invaded my area. I applaud you on your effort to handpull all the weeds! It is a daunting task. Rarely have I seen shoots come up from mowing, since it is an annual. Most of it's energy has already been used produce the plant. I do use chemical that will kill the plant and have a residual on the ground so that any seed that was produced will not grow. Good luck on your efforts

Kim said...

Sheryl and James,

I just discovered star thistle on my property in Blanco, Texas. Now that my eyes are open to this nasty weed I have noticed it in many small towns in our area. I have 8 acres to clear, you are is a daunting task! We are trying to avoid chemicals for our section of the world. However, I have to say that I saw some places with acres (maybe 5+) heavily covered with the thistle. That land was affected by overgrazing and the drought. It is a real emergency in my opinion, as this weed is taking over the native plants and grasses. One property that I visited had been mowed several times and the weed spread laterally covering the ground. I was advised during a land management seminar that if the acreage was too large to simply pull the weed by hand that shredding very low followed by an application of chemicals (Grazon and Remedy) might help. I heard that Ladybird Johnson Wildflower Center is suggesting broadcasting Indian paintbrush seeds to the vacated area as it competes well with the thistle. I hope that people become aware of this weed and start pulling it up. I take much delight in seeing your blog as we obviously are working together in a slow conquering of this ugly weed! Thanks for a great post!

Sheryl Smith-Rodgers said...

Thank you, Kim and Anonymous, too! (I'm behind in responding.) I'm still pulling thistle and beggar's ticks, too (Torilis arvensis). It's very overwhelming, and we'll never get all the thistle. But we're trying!

Karla Pfennig said...

START NOW!!! new crop of Malta thistle is up with the blue bonnets (in October this year 2012). It sets a seed at the base early and that one has fallen off by the time you harvest the size in the photos. I have cleared a monoculture of these things off nearly 20 acres. I have photos and documentation of this, I am in Hays county under wildlife management. I can send what to look for.

Karla Pfennig

Sheryl Smith-Rodgers said...

YES, please send me info! May I post it on this blog?

Marie T said...

I spent hours and hours pulling Malta Star Thistle by hand from about 1/4 acre late last spring. Drug out like 16 huge bags. This year I’m pulling it earlier. Hopefully I can control it. I wish I would have know what it was when I first saw it before it took over. Oh well it gives me something to do and think about besides the Corona Virus. The weeds remind me of the virus. Early detection and prevention is key. Stay safe everyone!

Sheryl Smith-Rodgers said...

Good for you, Marie! Just yesterday I pulled some from a nearby city easement. James and I cleared a lot from that area a few years ago. Now we monitor it, and there's still some malta star that comes up.

Marie T said...

Hi Sheryl, I'm still trying to rid my back 1/2 acre of Malta Star Thistle and am hoping it won't return but am reading online that it will. Did you ever get the information from Karla Pfennig who also commented above? I would love to have that information. Thanks Marie T.

Sheryl Smith-Rodgers said...

I guess I didn’t, Marie. I’ll try that email address.

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