First Signs

First sign of autumn color in Mono County (Alicia Vennos – 8/23/12)

California Fall Color has begun hearing from color spotters that the first signs of fall color are appearing… still a month from the official start of autumn!

The photo at left was shot today by color spotter Alicia Vennos of an aspen in Mono County.  And, so we are able to say that Mono County is the first to report and that color is showing 0-15%.

Newly “knighted” color spotter Carol Brandt reports from San Rafael (Marin County) that “the cherry trees have a quarter of their leaves turning orange/red, several large Liquidambar are also changing color to orange/red, with Japanese Maples going from their deep-red summer color to lighter orange and yellow.  Carol’s lilac trees have completely gone from summer green to bright yellow and apricot leaves are turning yellow.”  So, let’s put Marin County on the charts (at least for the exotics she describes), as 0 – 15% have turned.

For those unfamiliar with our scale, it is the same color scale used by The Weather Channel (they asked that we use it for consistency).  It measures the % of overall change of color in a forest, not on a given tree.  We think it’s also helpful to guide trips to see color.  Leaf peepers and photographers want to know when to be in a given area when it’s approaching peak or at peak, the scale helps guide travel planning.

Let’s use Alicia’s photo (seen above) to illustrate why we measure change in this manner.  Counting the leaves on the branch in her photo, there are five orange leaves and about 20 green ones.  So, the % change on the branch is 20%.  However, for the forest, it’s 0 – 15% changed, as while some change is showing, it’s inconsequential to the color change in the entire forest.  The same is true when we get to the end of change for a given forest.  If 90 out of 100% of the leaves have fully turned color, then the forest is said to be in the range of 75 – 100%.  And, once most of the trees have dropped their leaves or fully lost color, we call it “Past Peak.”

Given that primer, here’s the full Weather Channel scale:

  • 0 – 15% (Little to no change of color, some lime, mostly green)
  • 15 – 30% (slight change of color, lots of lime color, some yellow)
  • 30 – 50% (approaching half the foliage is showing color)
  • 50 – 75% (approaching peak, lots of color, still some lime)
  • 75 – 100% (at peak)
  • Past Peak (most leaves have lost color or been blown away, though some pockets of color may exist)

The scale indicates the % of change, but it doesn’t help knowing when you should plan to be in a certain area.  Lots of factors can affect color change.  Look back at our previous blogs and you’ll see cases where we were reporting 30 – 50% and within a few days it was peaking.  This is particularly so at higher elevations, where color can change suddenly.  If we write “Go Now,”  we don’t guarantee how long the color will last.  It could be gone the next day.  “Go Now” means delay your trip not later than the end of that week.  Even then, there are no guarantees.  A wind storm can knock leaves from trees (as we photographed last year) in a matter of minutes.

What we have noticed fairly consistently through the years is that leaves that have not yet changed color aren’t usually blown from trees and even some with a little color change in them will hang on through a storm.  Though, fully turned leaves are most vulnerable to wind storms, particularly at higher elevations.

1 reply
  1. Jyoti says:

    Hi John!

    The trees in East Bay and South Bay are showing significant coloring now. Many are in the 15%-30% stage, while almost 70% of the deciduous trees in the 880 N, Fremont Blvd, Almeda creekside… are in the 0%-15% stage. Will try to catch a few pics and send.

    Jyoti

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