Connie Gannon, executive director of Greenspace–The Cambria Land Trust, wrote for The Cambrian on fighting invasive weeds in Cambria:
They’re everywhere! What are those tall spiny plants with small fuzzy purple flowers growing up the stem, or larger round fuzzy flower heads at the top of their stems? Thistles. The ones with small flowers are Italian thistle (Carduus pycnocephalus); those with the larger round flower are bull thistle (Cirsium vulgare). And there is some yellow-flowering star thistle (Centaurea solstitialis) around, as well.
Because of major seed drops in previous years and a lot of rain this winter, 2017 is proving to be a banner year for thistles. Up and down our roadways, spreading across our pastureland, marching into our vacant lots and even pillaging our downtown median and parking strips.
Covered with tiny barbs and larger thorns, they aren’t a plant you want to gather by the armload for spring bouquets. But are they really harmful?
Yes, they are. The thistles named above — Italian, bull and star — are highly invasive. They can overwhelm pastureland, and cattle don’t readily eat them unless trained. While they do feed pollinators, they also crowd out and divert water from beneficial native plants that would normally grow where the thistles have taken over.
You don’t need to cut down the whole plant. Weed abaters will come later and do that. But the only way to stop the thistle is to remove the flowers before they go to seed.
As we can see all around Cambria, they are indeed making their move to take over our open spaces. What can we do? The Cambria Forest Committee and Greenspace — The Cambria Land Trust are launching a campaign to encourage Cambrians and our neighbors to join the Thistle Battalion. This popular uprising, armed with clippers, long-sleeved shirts and large plastic bags, can advance, street by street, neighborhood by neighborhood, to halt the spread of these troublesome invasive plants.
These are the tactics:
▪ Wear protective clothing and garden gloves.
▪ Use common garden clippers or shears.
▪ Work as individuals or neighborhood groups.
▪ Set out in the morning, perhaps after coffee and a hearty breakfast.
▪ Clip the flowering stems off as many thistle plants as you can locate on your block, adjacent to your church or club, on Main Street, or wherever you feel led to attack.
▪ Be sure to toss each and every one in a large plastic garbage bag. This step is essential.
You don’t need to cut down the whole plant. Weed abaters will come later and do that. But the only way to stop the thistle is to remove the flowers before they go to seed. Pour the bagged flowers directly from the bag into your greenwaste bin. They will be trucked to Santa Maria, and added to municipal compost heaps there. Heat in the compost should be high enough to kill the seeds.
A word of warning: Please do not decapitate the low-growing thistle with the large spherical head and dark red-purple blossom. This is the native cobweb thistle (Cirsium occidentale). It is rare and is a protected species.
The time to act is now — in a couple of weeks, the seeds will have dropped and the battle will be lost. Thank you, ready soldiers. Working together, we can rid our lovely town of this pest. May the Forest be with you!