The Friends of the Wilderness Park are planning to offer more educational events for those who would like to know more about the natural history of the CHWP.
Our first offering is a collaboration with the Pomona Valley Bird Alliance to bird this diversity hotspot (990 species of organisms on the Friends’ iNaturalist CHWP Biota project, 133 species on eBird). We will take a holistic approach, observing the birds as well as the natural history they are associated with on this 2-3 hour walk.
This is a great opportunity to learn about using eBird and iNaturalist to share your observations of birds and other wildlife. If you’re interested, please download the apps to your phone before you come to the Park, as cell phone reception in the Park is spotty at best.
Meet at the entrance gate to the park at 7:00 AM. Parking is free for 6 hours for Claremont residents in the south parking lot at Mills and Mount Baldy Road and $5.00 for nonresidents at the north and south lots. Bring water, sunscreen, sturdy shoes and binoculars. Limited to 15 participants. To participate, register here.
The weed workers – Dick, Peter, Lea, and Kathy – with 10 big bags of thistles!
On Saturday, November 1, a group of hard-working weed warriors removed invasive Russian Thistles in Johnson’s Pasture from the sides of Johnson’s Pasture Road, Webb Canyon Road, and a social trail that links the two.
Russian Thistles, which actually aren’t thistles, can be any of several species in the genus Salsola. So far as we know, the ones in Johnson’s Pasture are all Salsola australis, which, as you might guess from the name, came from Australia, not Russia – so they’re neither Russian nor thistles. To be fair, the first Russian Thistles to reach the US were Salsola tragus, which was inadventently introduced into South Dakota around 1874 in flax seed from Russia. And the name Russian Thistle stuck and was applied to all the similar Salsola species.
Starting in late fall Russian Thistles dry out and die, their seeds nestled between prickly dried leaves. Gusts of wind easily break dead them off from their roots. A microscopic layer of cells at the base of the plant — called the abscission layer — makes a clean break possible, and the plants roll away as tumbleweeds, spreading their seeds.
When the rains come, Russian thistle seed germinates very rapidly. Each seed contains a fully formed embryo coiled up inside that uncoils as it germinates. The young taproot extends into the soil within about 12 hours. During this rapid germination period, Russian thistle has an advantage over many other plants under limited moisture conditions. A minimum amount of moisture, lasting only a few hours, will allow germination and root growth to deeper, subsurface moisture.
Large Russian Thistle tumbleweeds can reduce roadway safety by obstructing views along rights-of-ways and causing drivers to swerve their cars to avoid colliding with them. Tumbleweeds accumulating against fences, houses, or natural barriers also pose a fire hazard, and ignited balls of burning Russian thistle blowing through grasslands can spread fire. In the cities of Palmdale and Lancaster, tumbleweeds are such a big problem that Los Angeles County spends $100,000 to $150,000 yearly clearing them.
Fortunately, the Russian Thistle problem is not that big in the Wilderness Park, but we have clearly noticed their numbers increasing, so it’s good to attack them before the situation is dire.
The crew did an outstanding job today, but there’s more of the Park to attack, so we hope you’ll think about joining us for another Russian Thistle removal outing!
Enjoy some photos:
Close-up of stem, flowers and fruit, and prickly leaves of a Russian thistle.Kathy and the other weed workers removing thistles from the social trail that connects Johnson Pasture Road to Webb Canyon Road.Peter with a big Russian Thistle.Peter stomps down a Russian Thistle so it will fit in the bag.This might have been the biggest of all!
Croftonweed (also known as eupatory, thoroughwort, sticky snakeroot, catweed, hemp agrimony, sticky agrimony, and sticky Eupatorium – scientific name Ageratina adenophora) is toxic to humans, horses, and other animals, and also produces chemicals that inhibit the growth of other plants. It spreads easily and crowds out native vegetation.
In 2019, we spotted a single clump of Croftonweed in Cobal Canyon, and since then we’ve seen it expand from a single clump to something like 50-100 plants. So wanted to get it out before it spread more and got even harder to remove. On October 4, a group of volunteers braved poison ivy to remove all the known Croftonweed from Cobal Canyon. We will have to keep an eye out for any sprouts that might come up from seed next spring, but basically, it’s Goodbye, Croftonweed!
This year Saturday, June 7 – Sunday, June 15 was California Invasive Species Action Week, a statewide, week-long event created to increase public awareness of invasive species in our state and to promote public participation year round in invasive species management.
For our June 14 Second Saturday event, we removed invasive mustard – including Short-pod Mustard (Hirschfeldia incana), Mediterranean Cabbage (Brassica fruticulosa), Oriental Mustard (Sisymbrium orientale), and Hedge Mustard (Sisymbrium officinale) – and Italian Thistles (Carduus pycnocephalus) from areas near the Park entrance that are being revegetated with native plants.
Some volunteers also did our usual trash pickup and greeted visitors at our booth.
Here are some photos of volunteers at work:
Weed workers getting ready.Charlie with a bag of thistles.Richard removing mustard along the fence.Mustard pulling in progress.Jessica pulling mustardTrash collectors Noelle and Tracy with our CISAW displayLook at that! Eleven huge bags of mustard and thistles!
And a little “Before” and “After”:
Area by the storage shed before mustard was cleared.Area by the storage shed after mustard was cleared.Thistles under the oak tree by the entrance.Under the oak tree after thistles were removed.
Friends of the Claremont Hills Wilderness Park 