Back in late December my brother and I collected and planted a couple hundred Quercus agrifolia (Coast Live Oak or California Live Oak) acorns up on the "upper 40" hillside at my parents' place in Santa Barbara. Due to uncommonly cold weather in spring of 2007, the acorn yield was very high this year, so collecting the acorns was easy. Acorns came from the ground and from trees. Generally we just scratched a hole in the leaf mulch or soil and pressed them in with our thumb. My father and I also started some in 1 gal containers filled with local soil in case we didn't have enough rain.
Well, we've had enough rain (even down in Los Angeles, where a couple containers with acorns sat out in my back yard and had supplemental hose waterings). One of the two acorns (or more? I can't recall how many I planted, but it was at least two) sprouted the other day. Quercus agrifolia oaks sprouts are red when they first burst on the scene, and it takes them only a couple days to develop a recognizable oak leaf shape.
I expected to see many similar small sprouts on the upper 40, where perhaps 200 acorns were planted. However, I wasn't able to find a single sprouting acorn. I did inadvertently dug up couple acorns that I had previously planted there. One had formed an extensive tap root, but no structure above soil. The other I was not able to accurately observe.
In the 1 gal containers, many of the oak sprouts had already sent their roots down the bottom and in many cases they had started to coil around the container interior. The above ground to below ground ratio must have been 1:20 in some cases. Perhaps root confinement causes early above ground growth. In any case, I'm not willing give up on all the acorns on the upper 40. I think there's a good chance that we'll see a number of sprouts. The process will be to wait a year or two and then select winners if there are too many.
Californiaoaks.org has a recipe for preparing and storing acorns to plant, but I've found that with the two species I've tried here in southern California, that none of the washing in dilute bleach and cold storage is necessary, if starting in containers. I place the acorns in a tub of water and select those that sink to the bottom, scrape the soil to a depth of 0.5 - 1", place the acorn sideways in the hole, (a little up or down doesn't seem to matter) cover, and water.
last year I tried the same thing with absolutely no luck. This year I gather some Live Oak seeds and took them home, water tested them, drained the water and then stored them in a plastic Dickeys BBQ cup until I could get some potting soil. I got busy and 4 or 5 days went by until I finally got the motivation to set the seeds in the pots. When I poured them out on the shelf, 2 of the seeds at the bottom of the cup had sprouted. Was it temperature? the moisture at the bottom of the cup? was it the flourescent light in the kitchen? or perhaps something else? I don't know- but I'm trying to repeat this process to see if I've arrive at something. you can see my facebook post of it with picture - lance tharp
ReplyDeleteI was just hiking up above the Palisades Highlands in Pacific Palisades (on the backbone trail to Will Rogers), and there were a ton of old acorns on the trees that were sprouting in mid air (which I collected). They didn't have roots of course, but the acorn was splitting and the sprout was starting to poke out. I'm curious to see how these do.
ReplyDeleteOn the sprouting in the cup issue: I'm certain it was the residual moisture, since you don't mention that you dried the acorns. I place mine on a towel in warm sunshine to dry and a semi-permeable refrigerator bag might help as well.
ReplyDeleteDrying the acorns after washing (with dilute bleach, if memory serves to prevent mold during long term storage) is key to preventing sprouting.
I've never seen acorns sprouting while still on the tree! I'm curious how those do. Please let us know.