On September 1, 2020, John Walkinshaw wrote to Rebecca Pollon, Landscape Manager at the time, about his thoughts on a potential Eagle Ridge Oak restoration project in Rossmoor.
John describes how this remarkable effort started: “Some 20+ years ago, I was involved in the Walnut Creek Oak Restoration Project. It came about because of the observation that not many young oak trees were on the hillsides. The project involved harvesting acorns in the Fall, preserving them in a cool environment, then once the rains came planting them in shallow holes. We usually put three acorns “kissing" at a site, covering them with just one inch of soil, but loosening the soil below them to about 12" (a spade depth). Each site was "flagged", so we could go back to check on growth, and do appropriate "protection" of the shoots. Even though there was a fair amount of attrition, John returns to the areas that he worked seeing very healthy oak trees that are more than 20' tall! He notes. “One of the reasons we started with acorns, is that nature is very clever in its desire to survive. If you dig up a site where the shoot is just breaking the surface (one inch long) the acorn has sent a tap root that is nine or more inches long! 'It knows' that there will be a dry season ahead, so must go deep (and spread out) to survive.
In John’s daily hiking along the trails of Rossmoor, he noticed that 2020 was a year of bumper crop of acorns (sometimes referred to as a mast year) on many different oaks. It occurred to him that that there might be an interest in giving nature a headstart by getting them in the ground at the right time. Relying merely on squirrels was insufficient! He asked Rebecca Pollon, our then Landscape Manager, if she might have interest in such a program. He explained, it would be a volunteer program, under her guidance, as to which oak types to harvest and to plant them. He acknowledged that once the seedling sprouted, there were likely some necessary expenses to protect them from being damaged by wildlife (e.g fencing).”
Rebecca responded enthusiastically on the same day! So, how did things get started?
Adrienne Roth, a member of the Trails Club of Rossmoor and Sustainable Rossmoor/Tree Planting and Preservation Committee, was also an early ardent supporter. She proposed that the 2 clubs could embark on a long-term project similar to John’s experience above with Walnut Creek’s Oak Habitat Restoration (www.wcosf.org/projects/oak.html). To recruit volunteers who wanted to participate in the acorn planting effort, Adrienne sent an email to the 2 clubs. More than 40 “acorn enthusiasts” signed up, plus many more who wanted to just plant on their own.
Meanwhile, Rebecca, John, and Adrienne scouted areas around Rossmoor to survey the best plantings sites. Rebecca was mindful of Rossmoorian desires to protect views and access near their homes. John and Rebecca were also aware of the best places to plant the different types of acorns. For example, Valley Oaks (Quercus lobata) prefer to have access to seasonal water. Areas near intermittent creeks are ideal, and north facing slopes have a better chance of success. (For more information about Valley Oaks: https://www.laspilitas.com/nature-of-california/plants/562--quercus-lobata)
Blue Oaks (Quercus douglasii) fare better on rocky, sunny slopes. They are rarer, and grow more slowly, so patience and perseverance will be the key with this important species. For more information about Blue Oaks: https://www.laspilitas.com/nature-of-california/plants/555--quercus-douglasii)
John and Rebecca provided detailed instructions on collecting acorns from these native species:
1 Keeping them dry in plastic bags and storing them in the refrigerator. The acorns germinate whilst in storage.
2.When ready to plant, in about December/January as the soil softens, the viability of the acorns can be checked by placing them in a bucket of water. Those that sink are viable and those that float are not.
3. For those interested in learning more, he provided a link to a Guide to Growing California Oaks: http://phytosphere.com/oakplanting/acorns.htm
After over two dozen volunteers collected and stored acorns, Rebecca, John and Adrienne scheduled a time to instruct them how to plant. Unfortunately, that was the commencement of COVID restrictions, and we could not meet as a group. Still, more than 500 acorns were collected. So John, Adrienne and a few others read the instructions Rebecca provided. Viable acorns were planted in many different sites in Rossmoor following the instructions and materials, freely provided, from the Landscape Department. Rebecca also planted acorns at many sites. There were numerous “squirrel plantings” too, just as squirrels do in Nature, in a small hole and covered with soil. Hence, you will notice various oaks growing in various places of varying sizes, some still young, some even adolescent. Though none, of course, are yet adults; to those of us who plant, water and protect them, knowing the value they have in their beauty and keeping our air clean, it is very gratifying.
The current Rossmoor Landscape Manager, John Tawaststjerna, is also very supportive of this program and has provided materials (taller cages) and some staff time to support the Rossmoor volunteers involved in the program. Our fully collaborative effort is recognition that our growing trees are there for current children and grandchildren to breathe and see in their glory.
Photo above: Rossmoor East Ridge mature oaks, and young oak in a cage, grown from the acorn planting effort.