Tree Blog

Quercus shumardii | Bay Area

These are Shumard Oaks (Q. shumardii) growing at a nursery just inland from the Bay Area. Shumard Oaks provide variable but consistent fall color. Some members of the Eastern Red Oak group display a leaf trait which is universally hated in California. These trees hold their dead leaves, roughly the color of paper bags, all winter long, until they are pushed off by the expansion of new growth in the spring. This trait is called marcessance, a term which some remember by noting that marcessance mars the landscape. Red Oaks (Q. rubra) consistently drop their dead leaves in the winter. Pin Oaks (Q. palustris) typically holds dead leaves all winter, adding to the inappropriateness of the species to California. Scarlet Oak (Q. coccinea) typically hold their dead leaves for the first decade or so after planting, but, with maturity begin to drop dead leaves cleanly in the winter. Shumard Oak (Q. shumardii), unfortunately, has no species pattern. Some hold dead leaves in winter, some don't. In twenty years of observing a thousand or more specimens in California and Oregon, the split is rather neatly fifty-fifty. If non-marcessant Shumard Oaks are required, the trees must be observed growing in the winter, without human interference.

Dave Muffly