[fourteen410]

In traveling throughout the state, I've noticed a significant number of deciduous trees are still hanging on to their autumn leaves. I suspect the unseasonably high temps in October played a role. Anyway, that got me wondering: will these old/dead leaves impact the growth of new leaves in the spring? Or will they fall off by then? Pics from the Tieton area a couple weeks ago for example.

[GaliWalker]

Here on the east coast, it’s common for some deciduous trees to hold on to a few of their leaves until spring. These fall off when new ones emerge. e.g. This was taken on Feb 19th:

[Bernardo]

White Oaks keep their dried leaves until Spring. The first picture looks like a type of White Oak.

[zephyr]

[Mike Collins]

It is unclear just why some trees have evolved the adaptation to retain their leaves in autumn (marcescence). One postulate is that the retention of the leaves on the tree serves to decrease the time of decomposition once the leaves are added to the ground litter. That would allow the nutrients to be available to the tree faster. https://link.springer.com/article/10.1007/s11104-017-3318-6

[Sky Hiker]

I noticed the coniferous/decidious Larch tree seemed to be changing color earlier than normal this year. Probably due to the early cold snap we had.

[marta]

The wikipedia article on Marcescence has a good overview on it. I do agree that the leaves in general have been late in falling this year. We have a beech in our yard and it held on to its leaves until after the December snow in the Seattle area.

[rossb]

Yes, big year for Marcescence. I've seen it around town, as well as in the mountains. I don't think I've ever skied over so many leaves (well into December). My guess is it had to do with the early cold snap (as Sky Hiker mentioned). The Wikipedia article mentioned that as well.

[fourteen410]

[BigBrunyon]

These are referred to as deciduus cause the leaves fall

[treeswarper]

Stay tuned. It was the maple trees here that got caught with their leaves on here. We had no fall here. We went right into winter, with a heavy snowfall and cold temps from the get go in November. Until then, we'd only had two frosts and I was wearing shorts outside daily. We had a late, wet spring too. My tree was abused in the past and is not the healthiest. A renter lived here before I bought the place, and skimped on watering. I was reading that OVER watering can cause this leaf thing to happen, but there are brown leaved maples all over town so I don't think that's the cause. The tree still has brown leaves on it. A few blow off when we get wind. We'll see if it comes back to life in a few months. I sure missed having the bright yellow leaves in the fall to look at.

[IanB]

Regarding the number of trees holding leaves this fall. Trees have to prepare to lose leaves in the autumn. Besides the withdrawl of valuable compounds into the vicinity of the bud where they can be recycled the next season, the base of the leaf needs to develop a corky shear zone where it will separate from the stem. Counterintuitively, this is a growth process - a biological action that requires metabolizing sugars has to be undergone to create that shear point. In the early autumn when hot, dry conditions persisted, trees didn't have the moisture necessary to do that biological work in a complete and timely manner. By the time the rains came, temperatures were lowering, also making it difficult to perform the task. In the end many leaves died in place and remain on the their tree until finally whipped and worn by wind and freezing temperatures...

[treeswarper]

[kbatku]

With the intense heat hitting the west side of the state now I've noticed a lot of heat-stressed trees that really need to be watered (in the cities). City folk on the west side aren't familiar with watering treses but they better figure it out quickly of they will lose a bunch of old well-established trees as well as newer ones just getting growing. Someone needs to do a public information campaign to encourage residents to water their trees, including spraying the foliage as high as the water stream will reach

[Mike Collins]

The western red cedar are taking a hit also and have been called “…a canary in the coal mine.” https://www.opb.org/article/2022/09/06/western-redcedar-trees-are-struggling/