Every time I rode the Harley back to my Sierra Nevada mountaintop home I cruised at rather high speed down the Bullard's Bar Grade into Dobbins.  Riding motorcycles requires all my attention to stay safe on those crazy crooked roads in the high country.  Yet sometimes I'd catch a flash of color out the corner of my eye, and I'd always have to go back and find the source.

This time it was golden yellow, which was strange because the gold Scotch broom had long ceased their early flowering.  Nothing bloomed at that time of year in such density at 1800 feet.

To my surprise I was Fremontadendron californicum, the native species that has yielded such incredible bloomers as 'Calfornia Glory'.  But this is the wild form micro-adapted to the Sierra foothills where conditions are far more trying than those experienced by the same species in the coastal foothills.  Therefore these plants were low and spreading, anchored by roots into a barren south facing slope.  Below the parents, seedlings sported their first flowers in the loose alluvial soil that accumulated at the toe of the slope.  Perhaps there had been many more on the mountainside above at one time, but logging and the regrowth of manzanita choked them off. 

From that day forward I began watching for more Fremontia.  In almost every case they were growing on eroding south facing slopes in acidic soils heavy with decomposing granite.  And always they perched at the top of the slope, perhaps feeding on topsoil above or simply sticking to the fastest drained ground.

Gardeners have always had a hard time growing Fremontadendron.  This roadside study tells you why.  The plants demand an open, south facing expoosure.  They do not like rich topsoil.  The ground must be loose and porous with a clay subsoil deeper down for anchorage. 

Try to grow this plant with these demands anywhere else and they probably won't live long.  Perhaps those I've seen have managed to survive due to cut slopes created by road building or cutting irrigation ditches and fire roads.  With this land so damaged by logging early in the 20th century, we have no way of knowing how they grew before the wilderness.  But at least I know (and now you do too), by observation, exactly what they need.