Immature Green Pine Cones
We have lived in our home for nineteen years and have Douglas Fir trees. This year we are seeing an abundance of green immature pine cones falling in our yard. We always see many pine cones throughout the year but in the past they have been brown and mature. Is there an explanation for why we are seeing the green immature ones this year? Just curious.
Jerry Robinson - Vancouver
I can think of a couple possibilities. One is that it just happens to be a really good cone year for the Douglas-fir in your area. This happens on a sort of cyclical basis. And possibly, out of that abundance of cones, it's just dropping some. Or perhaps an animal (bird or squirrel) is cutting some of the cones off.
It's also possible that the tree has put out a flush of stress cones. This happens when the tree is dying and it makes a final effort to reproduce.
If the tree looks otherwise healthy and other trees in the vicinity also look like they have a lot of cones, my guess would be that it is just a good cone year and that you will see lots of both immature and mature cones on the ground through the course of the season.
If the tree looks sickly (yellowing, thinning foliage) and is the only one with a lot of cones on it, then that's cause for more concern.
Ultimately, if there don't appear to be any other troubling symptoms, I would just take a wait and see approach and monitor it over the next 1-2 years.
Kevin, thanks for taking the time to answer my question. I have lived at my residence for more than 19 years and this is the first time I've seen this happen. Also, when walking around our neighborhood, I am noticing the same immature green pine cones in other's yards. Our trees appear to be healthy. It may be nothing but I found it interesting and wondered if there was a known reason for the drop. Take care.
I finally heard back from an expert in conifer cones, and he was not aware of any sort of pathology that results in aborted cones. He reminded me, though, that we are seeing a lot of mortality, damage, and otherwise odd behavior this spring as a delayed reaction from last summer's record-breaking drought period, not to mention an abnormally dry/warm period earlier this spring, so it may just be an off year all around for some trees because of the weather.