by Betsy Herbert
published in the Santa Cruz Sentinel 10/16/14
October is a great time to hike in the redwoods. Even during Indian summer heat waves, the air is cool beneath the big trees. Leaf color in the forest understory is starting to change. Sword ferns, redwood sorrel and hazelnuts are still green, but big-leaf maples and sycamores are turning yellow and poison oak is turning bright red.
Earlier this week I donned my day pack and headed for Henry Cowell Redwoods State Park, hoping to encounter one of my favorite natural occurrences in the redwood forest...the annual seed-drop. In case you haven’t experienced this small wonder, I will describe it. Several years ago in Bonny Doon, about this time of year, I was walking beneath a large grove of redwoods when I heard a strange crackling noise all around me. It sounded almost like a light hail storm, but it was a warm day. When I stopped to listen more carefully, I found myself in the midst of a shower of thousands of redwood seeds, each about the size of a tomato seed.
As they fell from cones high in the redwood canopy onto the leaf-strewn ground, the seeds made a cacophony of little popping noises. . .the sound of the next generation of giants taking shape.
I stopped in at the Henry Cowell Redwoods Nature Center to ask about my chances of witnessing the seed drop. Dennis, a volunteer State Parks docent, showed me a display of small lime-green redwood cones that had just been collected in the park. Each cone was about an inch long. The cones had just started to open and release their tiny seeds, which were also on display. He said that the seed-drop may have been early this year, due to the drought.
As I hiked the loop trail around the big trees, I spotted a few of these small green cones on the ground, but there was certainly no ongoing seed-drop. Later, I examined some of the redwood tops through my binoculars and saw that the branches at the top of the tree were absolutely loaded with little green cones. Redwood cones normally open from September to March, coinciding with California’s rainy season. So, perhaps the seed drop is yet to come this year.
A little research revealed that coast redwoods are prolific cone-bearers, and that each cone bears 90-150 seeds, though many of them are not viable after they reach the ground. Redwoods start to bear seeds when they are young, between five and eight years old, but trees more than 250 years old produce the most viable seed.
Despite the many thousands of seeds that each mature redwood produces, only about 3 to 10 percent germinate. Viable seeds will germinate as soon as they get wet.
It’s not easy for a redwood tree to get started. Once they’ve sprouted, redwood seedlings need adequate moisture to survive. They are also susceptible to fungus infection and to consumption by banana slugs and rabbits.
Fortunately, redwoods have another way of reproducing-- through stump-sprouting. Each stump sprout is a tiny growth emerging at the base of a tree. Both healthy trees and cut stumps produce sprouts. A redwood stump sprout can eventually become a full-size clone of its parent.
According to Jessica Friedman, State Park Interpreter, “No matter what season you visit Henry Cowell Redwoods State Park, you’ll find something of interest.” Autumn activities include a “Basket Making Workshop” on Saturday, October 25, 10-noon at the Visitor Center; and “Birding for Beginners” on Sunday, October 26 at 8:00 a.m at the Nature Store.