Sunday, January 17, 2010

Rambling the Arroyo

This morning before the rain, my son and I enjoyed a short stroll along the lower Arroyo Seco with KPCC environment reporter Molly Peterson. We parked at Pasadena's Lower Arroyo Seco Nature Park and headed north toward the Colorado Street Bridge (pictured above).

My 2-year-old walked this, but most of the trail is accessible with a jogging stroller.

Under the bridge, concrete disappears and the stream meanders. Last summer, the Arroyo Seco Foundation partnered with the City of Pasadena to restore a petite native fish, the Arroyo Chub, to this area.

Willows and mallards also inhabit the stream bed, as do invasive plants such as Mexican Fan Palm, and cape-ivy (below). The latter is an especially brutal weed, as it will climb shrubs and trees and smother them. Left to its own devices, cape-ivy (Delairea adorata) will blanket the entire terrain, preventing seeds of other species from sprouting. It can be hard to tell destructive ivy from its more benign relatives, so weed experts advise gardeners to avoid ivy altogether.

After our short Pasadena walk, we drove a couple miles south to South Pasadena Nature Park, which flanks the Arroyo on the south as the stream swings west.

Horticulturist Barbara Eisenstein has led volunteer efforts to restore this stretch of the Arroyo. Eisenstein says the primary approach has been to try and get the upper hand on the worst weeds, including castor bean, milk thistle and ailanthus. She adds,
More recently I have been ready Bringing Back the Bush - The Bradley Method of Bush Regenerationwritten by Joan Bradley. The method is based on work by Joan and Eileen Bradley in Australia. Basically it calls for working from areas where native plants are doing well towards more degraded land. This allows the native plants to move out into the weedy areas. If one just removes weeds leaving a void, the weeds are always at an advantage for reestablishment.
We will be having a "Planting Party" on January 23rd with student volunteers from Occidental College (MLK Service Day) and community volunteers. We will be planting close to the central kiosk where the buckwheat, giant rye, coyote brush, toyon and oaks were planted in 2004.
The park has come a long way since it was "restored" in 2004. As we control weeds we are beginning to see native plants taking hold on their own. The buckwheat and California fuchsia are spreading from the 2004 planting. We have seen deerweed and datura, both native plants common in disturbed areas, and at my last visit I noticed some fiddleneck (Amsinckia). We have a long way to go but we are definitely making progress.
On our visit, Peterson helped my son photograph a toyon bush. He also enjoyed watching a trio of horses (plus riders) heading for the nearby stables.

Despite the weeds, the park is a refuge for native plants, including this lovely oak.

I enjoyed seeing the fluffy white blossoms of this coyote brush (Baccharis pilularis) glittering in the sunlight.

This park is just east of the bike trail that runs for two miles along and in the (channelized) streambed.

Lower Arroyo Seco Nature Park is located below Arroyo Blvd at Norwood in Pasadena. To get to South Pasadena Nature Park, head south on Arroyo until it meets Pasadena Avenue. The park entrance is on the right side, just before the road re-crosses the 110 Freeway.

1 comment:

  1. Thanks again, Ilsa, for the write up. I am keeping my fingers crossed that it won't be raining on Saturday when we are planning our "Planting Party."


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