New year, new ideas 2018

It is still two months before the start of the growing season for Iowa sequoias. This winter inflicted yet another massive blow to the non-native trees. Several leaders are dead or nearly dead at this time. Several dozen 1-2 year seedlings were frozen out and are completely brown. 

#255 died after winter 2017/18 exposure

But not all hope is lost. Most of the 5 year olds still have green branches at the base. Many younger seedlings covered with foam cones are looking fine. A detailed report will be published later as the spring unfolds.

Most of this post is about the findings and ideas based on the trip to Kings Canyon and Sequoia National Park.

I traveled to these two parks located reasonably close to each other in the early spring of 2018. Unlike most people in the park who were looking at the largest specimens, I was seeking out the very youngest and the ones with visible damage. I was looking for examples of how they grow in their natural habitat. Here is what I learned and ideas that I am planing to implement on my Iowa plantation.

First of all, even here in California there were many damaged and dead sequoias aged between two and ten years old. I have not seen any dead sequoias older than 15. There was one pretty heavily damaged sequoia aged probably around 15-20 years on Stanford University campus but I don’t believe it was near its death. 

Giant sequoias on Stanford University campus, March 2018. Some visible damage.

That was by far the worst I have seen out of dozens "young" but established sequoias in the 15-50 year range. I can't quite tell the age of older sequoias but there were definitely no visibly damaged sequoias older than that.

There were plenty of other species of conifers of all ages completely dead, so giant sequoias were definitely a standout as in once they get stablished they tend to survive better than other trees. The reasons for other conifer deaths were cited as drought and insect damage.

One conclusion from this first observation relevant to my case is that the longer trees survive the better chance they have to establish. It's not an earth-shattering observation of course, but keeping them protected more aggressively over the first ten years still makes sense. Second conclusion is that it may make sense to limit their vertical growth for the first 10 years to allow heavier protection. I can not keep them "under a blanket" for 30 years but perhaps I can for the first 10, given I continue some vertical trimming. So far the best preserved sequoia is the one that lost 80% of the trunk last winter and re-grew decent volume during last growing season:

#207 March 2018. Lost major volume during 2016/17 winter but recovered in 2017. Minimal damage during 2017/18 winter after being kept under foam cone.

I might as well start forcing them to lose the height in a more manageable fashion. I will set up several test cases with varying amount of trimming ahead of the next winter.

Second observation from the Sequoia National Park trip was that although there were several seedlings and saplings standing alone, vast majority of the youngsters were encountered in patches of dozen or so. In those patches dead trees were seen on the edges. It is hard to make any conclusion as to why they get damaged, being so close to other normally looking trees:

36.7507 -118.9775 (36°45'02.5"N 118°58'39.0"W)

 Kings Canyon Park near General Grant Tree

Patch as observed from the trail:

Practically all patches had trees of different ages, which was surprising to me. I would think that if the conditions were favorable for germination one year, all seeds would germinate then, not over the period of several years. Apparently I was wrong:

Two 4-5 year old sequoias with one 2-3 year old next to them.

This sighting was pretty typical, where a mix of young but clearly differently aged sequoias stood together. This was quite a stark sighting because most of the forrest floor is not covered with young sequoias, but where patches occurred they had a mix of ages.

A conclusion that I am making for my experiment is that perhaps sequoias benefit from close proximity of other young trees and perhaps even from the fact that they are of different age. One idea is that they protect each other from the natural elements. This spring I will plant several younger seedlings next to the already planted older ones, creating artificial patches.

A pattern that I was aware previously but which was also standing out was that the patches were located next to the streams.