Summer is great but sometimes I yearn for the renewal the first rains will bring. When I'm feeling stranded in the drought, nostalgic for autumn, I go acorn cruising.
When fall comes, I'm going to want to go and gather acorns. I have my favorite spots but you might not, so I'll share some of my cruising guidelines with you. The first and most important consideration is species. Different oaks yield acorns with different levels of bitterness. This difference is not in kind but in degree: in other words, the process is the same for leaching any acorn from any oak -- but some will take longer than others. Blue and Valley oaks (Quercus douglasii and Q. lobata, respectively) have acorns which leach rather quickly. California black oaks (Q. kelloggii) take a bit longer, but many people feel the richer flavor is worth the wait. Live oaks (any oak that doesn't lose its leaves in winter) tend to have extremely bitter acorns which take a really long time to leach, and I never gather these for processing.
For beginners, I usually recommend blue or valley oaks. This is a great time to learn to recognize these species and identify populations that are on land you have permission to harvest from. (For example, a friend's or neighbor's house, or behind your workplace.) Most private landowners are delighted to have someone pick up acorns in a mast year.
What's a mast year? Well, that brings us to the second criterion for picking your acorn spot. Oaks, like many other nutbearing trees, don't bear the same amount of fruit each year. (Yes, acorns, like all nuts, are technically a fruit.) They may bear almost no fruit at all for one, two, or even more years, only to release a hailstorm of acorns in a magnificent bonanza known as a "mast year". Amazingly, all the oaks on a mountainside or in a whole region will share the same timing, if they are in the same species. No one knows how oaks communicate with each other to achieve this. Some people think this irregular rhythm helps the oaks outsmart their natural enemies, like acorn-eating grubs, weevils, moths, and squirrels. So, ask around and see if you can get word of a stand that hasn't borne a lot of acorns for two or more years. (Homeowners are most likely to remember mast years, not lean years, so try and get them to recall when the last time was there were so many acorns on their driveway it was almost unsafe to walk.)
You can also just cruise around and check the development of young acorns on oak twigs. These are visible as early as the first week of June, when they will be pea-sized. All oaks are bisexual (each tree produces fruit as well as pollen), so if it's going to be a good year, every individual should have some visible acorns. If oaks experience a severe stress (or hear some signal we can't discern?) they can still drop their acorns before maturing them, so early-summer checks aren't failproof. But they're better than guessing at random, and they also help you get to know your local oak forest. This cruising is best done on bike, because you can cover a lot of ground but can also stop frequently and check oaks out or talk to people who wonder what the heck you're doing.
Trees of almost any age can bear acorns, but older trees tend to have heavier harvests that are easier to gather.
Finally, you should consider making fire your ally. Recently burned areas may have the best acorns of all. Native Californians had many good reasons for setting frequent, low-intensity fires in this part of the world, but one of the most important was to reduce the eggs and larvae of acorn pests that can build up under oak trees. If you can find an oak grove that experienced a low-intensity fire last year (or even this year, if the oak kept its leaves), you may find that the acorns you gather contain fewer pests and last longer in your pantry. Restoring fire to our landscapes would have too many benefits to count. Improved oak woodland regeneration would be one!
Once you've located the grove you hope to harvest this year, it doesn't hurt to spend as much time with the trees as you can. Many people ask the trees for a good harvest, or permission to gather. Some "negotiate" with the jays and squirrels. Whether you're comfortable talking to the trees or not, I'm 100% confident that spending time with them will make your summer a much more enjoyable and hopeful season!
To learn how to process your acorns -- and do it in a fun, family-friendly atmosphere with plenty of acorn goodies to snack on -- sign up for one of our daylong acorn intensives this fall. These will be memorable events with something for everyone to enjoy!
You can see our Clinics page for more details or our Facebook Events page as well.