Tree Blog

Quercus gravesii x agrifolia | Santa Barbara

In 2008, nearly 500 Q. gravesii acorns were germinated as part of Oaktopia nursery project. Over the next year, all but perhaps 15 of these died. The survivors were grown on, with two of the survivors growing much more vigorously than the others. All of the survivors had leaves that were slightly different from the parents, and also were closer to evergreen than the two Q. gravesii planted in the Shields Oak Grove in Davis. A decade later, the survivors are still surviving, and several of them have been planted into the landscape. Shown here is one of the survivors, growing in Santa Barbara. For may years, the paternal pollen parent has remained a mystery. Now, as the trees grow out and begin to display mature traits, it's quite clear that the male parent is Q. agrifolia, the California native Coast Live Oak. Green leaves are held until the spring, and then leaf coloration, leaf fall, catkins and new growth occur roughly simultaneously. The trees are extremely ornamental during this time, and have great looking green leaves throughout the growing season.

Dave Muffly