It’s been about a month and a half since Tropical Storm Hilary soaked Southern California with record-setting rainfall.
The unusual amount of Summer rain has resulted in a second Spring at Ahmanson Ranch, with some plants behaving as if it were March or April.
Not only are plants growing as if it were Spring, some are flowering. The lupine pictured above usually blooms at Ahmanson Ranch in March, April, and May. Now, as a result of T.S. Hilary’s rain, it’s flowering in October!
Those plants that usually flower in the Fall, such as telegraph weed, vinegar weed, and common sunflower, are much more widespread than usual.
Spring-like conditions are present in many areas of Southern California. On Sunday, I ran the Phantom Trail in Malibu Creek State Park. Some sections were so overgrown that it was challenging just to navigate the trail, much less run it. Ticks were also a problem.
It was a little past 3:00 in the afternoon when I passed this straight-backed wooden chair along an Ahmanson Ranch trail. The Tempe thermometer clipped to my pack read over 100 degrees.
It gets REALLY hot at Ahmanson Ranch (Upper Las Virgenes Canyon Open Space Preserve). In the direct sun the temperature can be 10°F-15°F hotter than in the shade, and there is very little shade at Ahmanson. In-the-sun temperatures of 100°F or more are common in the Summer but can occur just about any time of the year.
There are two weather stations I use to get an idea of the weather conditions at Ahmanson Ranch — the Cheeseboro RAWS and Valley Circle Estates Weather Underground station. Weather station thermometers are usually shielded from the direct sun by a white, ventilated enclosure. The Cheeseboro RAWS includes a measurement of the “Fuel Temperature.” This is generally a better indication of the temperature experienced by a runner, hiker, or rider in the direct sun.
Update on July 29, 2023. Rounding the temperature to whole degrees, my West Hills weather station recorded a high of 100°F, or higher, for 15 consecutive days this July (7/13/23 to 7/27/23). The station is about three miles from the Victory Trailhead at Ahmanson Ranch.
After the Ahmanson Blue Oak in East Las Virgenes Canyon died this Winter, I started to search for another blue oak (Quercus douglasii) in Upper Las Virgenes Canyon Open Space Preserve (aka Ahmanson Ranch). Blue oaks are rare at the southern limit of their range, but I was hopeful that if there was one blue oak at Ahmanson, there might be another.
Valley oak leaves.
Typically, blue oak leaves are noticeably different than valley oak leaves. The Jepson eFlora describes the leaf margins of blue oak as being more or less entire, wavy, or more or less lobed. The leaves of the Ahmanson Blue Oak fit this description. Valley oak leaves are usually much more deeply lobed and readily identified.
Recently, while on a run, I noticed an unusual oak near the top of a service road on the western margin of Lasky Mesa. Its leaves are not deeply-lobed and are a bit more dusky than the usual valley oak leaf. But the tree doesn’t look quite the same as the Ahmanson Blue Oak. One difference is that the shape of the leaves is not as uniform as those of the Ahmanson Blue Oak. This might be due to the wet 2022-2023 rain season and the flourish of leaves that resulted. And, as with the Ahmanson Blue Oak, this oak was burned in the 2018 Woolsey Fire, and its trunk is partially hollow.
Blue oak-like leaves of an oak on the western margin of Lasky Mesa.
Based on its leaves, the “West Lasky Mesa Oak” could be a blue oak, blue oak hybrid, or valley oak hybrid. A 2002 study of a mixed stand of blue and valley oaks found that appearance can be misleading. When DNA tested, four of the five hybrid-appearing oaks in the study were not classified as hybrids. Of the four trees deemed most likely to be hybrids, only one oak was intermediate in appearance.
Although it seems unlikely this tree would have been overlooked, I could find no specific reference to the oak in the various studies and surveys done of Ahmanson Ranch. Please get in touch with me if you can provide additional information about this tree or how a DNA analysis can be arranged.
An unusually wet rain season not only increases the population of many wildflowers, it can produce wildflowers not usually seen in an area.
The Farewell to Spring (Clarkia amoena) pictured above was one of very small population found in Upper Las Virgenes Canyon Open Space Preserve (aka Ahmanson Ranch) in June 2023. The California native is much more common in the Bay Area and coastal Northern California. It probably found its way to Ahmanson by way of a local garden.
This year’s bloom of Elegant Clarkia (Clarkia unguiculata) in Upper Las Virgenes Canyon Open Space Preserve (aka Ahmanson Ranch) is even more widespread and lavish than it was in Spring 2020. It’s virtually impossible to do a hike, run, or ride at Ahmanson Ranch and not see the stalks of the oddly-shaped, 4-petaled, pink-purple flowers.
Dirt roads used to service gas pipelines that pass through Ahmanson Ranch have recently been scraped and graded.
Scraped and graded section of East Las Virgenes Canyon Rd about two miles west of the Victory Trailhead.
The work was sorely needed. In the wake of our very wet rain season, in some areas the mustard was 8 feet tall and roads were rutted and damaged.
All of the scraped roads are in the western part of Ahmanson, primarily in and near upper Las Virgenes Canyon. Some very welcome weed-cutting was previously done along the roads in other parts of the open space area.
(Officially named Upper Las Virgenes Canyon Open Space Preserve, most users refer to the open space area as Ahmanson Ranch or simply Ahmanson.)
