Showing posts with label California rainfall. Show all posts
Showing posts with label California rainfall. Show all posts

Monday, March 19, 2012

Rain Comes to Dry California

 What a difference an inch of rain can make!

Saturday it rained for over six hours. The rain gauge measured an inch and a third of spring-awakening water. By the next day, the Douglas iris committed itself to bloom.

While we are still in need of five or more inches to bring us into the “normal” range of rainfall, this gentle winter shower has washed the dust from the leaves and prompted some of the plants to reach for spring.
The Douglas iris is a California native and like all of our other native plants responds rapidly to rainfall. The deep purple blooms typically open throughout April, this year they're a bit early. There are hybrids of this native that come in a variety of shades, from white to deep purple and burgundy. Interestingly, in our yard, it is always the original purple that blooms first and is the most robust. The blooms last for a month or so, depending on the rainfall. The slender green leaves are fibrous and deep in color, they survive both frost and drought. We’ve been most successful with them planted in partial shade.

Our biggest challenge comes on four-tiny legs; pocket gophers that like to lunch on the iris’s rhizomes. If I can keep the rodents at bay, the Douglas iris comes back in larger clumps each year. Even if you initially put them in the wrong spot, they transplant easily. The Douglas iris demonstrates the beauty and practicality of planting natives.

They say it may rain again tomorrow. The iris and I are hoping that is true.

Monday, March 05, 2012

Facing Drought in California, 2012

What does the face of drought look like? Plants that typically should be robust and green in March displaying leaves curled from water stress.


non-native spider plant

native currant
Natives like the currant which should be blooming, this year are producing only leaves. There are ramifications for later in the year. A lack of blooms means no summer fruit. Birds and small mammals will find less to eat in August and September.


native bush anenome
Are we really looking into the eyes of a long dry summer? I keep track of the rainfall in my yard. There is a reason why the California slender salamanders aren’t out and about and why the bush anemone is looking stressed. We have had very little rain this season.


From October to April is our rainy season. In 2010, our first measurable rain arrived on October 6th and by the end of February we had received 12.58 inches of rain. This year our rainy season began on October 5th, but as of today, March 5, 2012, we have received only 5.375 inches.


The average annual rainfall in Los Angeles since 1878 is 14.98 inches. Typically, weather forecasters measure our rainfall against a rounded-up 15 inches. If you look at the graph of annual recorded rainfall, patterns are tricky to spot. There are years of less than 5 inches spiked with years of 20 or 30 inches.


seasonal rainfall numbers sourced from National Weather Service
But if you delve a bit deeper into the numbers you see that the mean amount of rainfall since 1878 is 13.19 inches (a few years of heavy rainfall actually push the average up). Over the last 50 years the mean amount of rainfall has dropped to 12.48 inches. The two lowest years are 2002 (4.42 inches) and 2007 (3.21 inches).


If rain doesn’t arrive soon, we will probably arrive in June with a total of less than 8 inches of rain, drought levels. This impacts every living thing in Southern California, from frogs and fish, to agriculture and humans. The hillsides and their wild residents can’t ask for more water from a river far away. They have to survive on what falls from the sky.


battered mourning cloak butterfly
The mourning cloak butterfly has awoken from its winter hibernation ready to find a mate and breed. But it is tattered by a long year of wandering and the flower blooms that it needs to survive are few and far between.