Victory over the Vinca? Not quite!

Posted on by friendsofthewildernesspark

On Saturday, December 6, a dedicated crew set out to vanquish what we thought was a small infestation of Vinca major (Big Periwinkle) next to the Cobal Canyon Trail.

Vinca major (Big Periwinkle) growing next to the Cobal Canyon Trail.

Big Periwinkle is native to central Europe and the Mediterranean region. It was introduced to the United States in the 1700s as an ornamental and for medicinal uses. With its dark glossy green leaves and showy purple flowers, Big Periwinkle has become a popular ornamental ground cover, but when plants escape to the wild and find favorable conditions, they can spread invasively, forming a dense ground cover that outcompetes native vegetation. It grows best in moist, shady conditions, such as riparian corridors. Such infestations along streams can easily spread, as small pieces of stem can break off, float downstream, and sprout roots when they land to start a new infestation.

On Saturday, the volunteers set to work, but as we tackled the infestation, we realized it went farther upstream than we had known, as it couldn’t be seen from the trail. It became clear that the upstream plants were older and much more massive root systems than the plants at the downstream end.

Volunteers hard at work on Periwinkle removal.
Paul tracks down Periwinkle underneath shrubs.
Claudia pulls Periwinkle off the slope
A thick patch of periwinkle upstream from the known infestation.
Yikes! The older plants had really big roots!
The crew – Johan, George, Dalia, Madeline, Paul, Cass, and Claudia (+ Heidi and Terri, not pictured) with their eight big bags of periwinkle.

Nonetheless, we removed all the Periwinkle from the originally targeted areas and some of the more upstream infestation. Here are some before and after photos:

The southernmost Periwinkle patch before removal.
What we thought was the main Periwinkle patch before removal.
The southernmost Periwinkle patch after removal.
What we thought was the main Periwinkle patch after removal.

Many thanks to all the hard-working volunteers! Stay tuned for another workday to tackle the rest of the Periwinkle!

Bird the Wilderness Park with us!

Posted on by friendsofthewildernesspark

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.

Questions? Contact Scott Marnoy to RSVP at gopherus2@gmail.com

Location: Claremont Hills Wilderness Park main entrance
Mills Avenue and Mt. Baldy Road, Claremont, CA 91711 

    Difficulty:  Strenuous-2-3 miles on gravel roads with elevation gain.

    Russian Thistles get the heave-ho

    Posted on by friendsofthewildernesspark
    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!

    Goodbye, Croftonweed!

    Posted on by friendsofthewildernesspark
    The Weed Warriors – Johan, Susan, Paul, Andrew, Heidi, and Nancy – with their pile of Croftonweed with Marcy behind the camera. ©Marcyn Clements.

    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!

    Nancy, Susan, and Heidi contemplate the task at hand. ©Marcyn Clements.
    Marcy pulling Croftonweed. ©Nancy Hamlett.
    Heidi and Marcy go after the Croftonweed. ©Nancy Hamlett.
    Our worksite with a big pile of Croftonweed. ©Nancy Hamlett.
    Croftonweed before removal.©Nancy Hamlett.
    After removal of the Croftonweed.©Nancy Hamlett.