Toadflax Farming


Dalmatian toadflax is closely related to snapdragons, and their flowers look similar. In fact, both of our invasive toadflaxes in North America were introduced as ornamentals and have since escaped cultivation.

“I’m so glad those nasty plants are finally out of here!”

This quote was brought to us at the end of last semester by one of the professors in the Department of Plant Sciences whose greenhouse is adjacent to that of my Masters advisor, Brian Mealor. The plants referenced, of course, were the Dalmatian toadflax which I had been growing with native grasses in nearly 400 pots.  The yellow snapdragon-like flowers were a gorgeous sight spread across two of the large sliding benches, but they belonged to a plant that has made noxious weed lists in at least 15 western states and provinces, including Wyoming. “Nasty” is by no means an inappropriate term.

I get a lot of jokes about being a confused weed science student. I received my undergraduate degree in rangeland ecology and management, so I’m coping with my new identity as a weed scientist by incorporating targeted grazing into my project. The purpose of my greenhouse study was to look at the toadflax’s response to different levels and types of defoliation before we begin working with the animals this spring. Then I decided to incorporate native grasses that are commonly found growing with my lovely yellow weed. That’s when my experiment grew so much larger than anticipated. Or perhaps the expansion occurred when the roots we collected from my field site turned out to grow far more successfully than anticipated (that’s the perk of working with nasty weeds: growing them for experimental purposes is not a problem). Either way, the experiment was rather conspicuous.

After a semester of growing the weeds, I was glad to see them go. I’m fairly certain the army of technicians and graduate students that appeared to help with planting and treating and harvesting was relieved, as well. I knew the plants couldn’t set seed (Dalmatian and yellow toadflax are self-incompatible, and no insect pollinators were frequenting our greenhouse in the middle of a Laramie winter) but all those perfect flowers still made me nervous. And I wasn’t the only one.


This is the current status of “round 2” of my toadflax farming adventure. These plants will be used to train sheep to eat toadflax before we attempt targeted grazing at my field site.

However, the thing about targeted grazing is that your animals need to be familiar with the plant they’re supposed to be targeting, to avoid an outcome of munched grasses and untouched weeds. With this thought in mind, we determined at the start of this semester that I should head back out to the greenhouse to start up another batch of toadflax plants with the leftover root pieces. After all, sheep are less easily trained than graduate students (although hopefully more efficient and eager when it comes to chowing down on tasty green foliage), and we want to make sure they know what they’re supposed to be eating. So the nasty noxious plants are back and, I’m happy to report, growing like… well, like weeds. I’m sure that this news will thrill the other greenhouse users to no end!

And me? The “rangey” part of this weed scientist is highly excited for the next step in this project. I don’t know yet if my sheep will prove to be a viable toadflax control. But I have figured out a backup plan: if all else fails, I can always take up toadflax farming.