It's summer again on the West Coast. The weather is hot, although thankfully pretty mild compared to previous summers. Our highs in Sacramento have been in the mid-90s F, not low-100s F. That's not only nicer to live/work in but also less stressful for the trees.
We concluded our spring update saying that this year is going better than last year. I am pleased to say that that trend continues. We're still ahead of some of the problems that plagued us last year (weeds, voles, water, etc.) and are seeing the tiny Okei pollinators starting to push more growth which is good. Below is an example of one such Okei pushing out the top of it's 3-foot Plantra grow tube.
Chestnut Tissue Samples
We took our first tissue samples in late May and received the results below back from the lab.
We then shared the results with researchers at Michigan State, and the Chestnut R&D Center in Italy, as well as Claude. We received good feedback from each source, with the folks in Michigan and Italy giving us a good, quick gut check that nothing looks particularly concerning.
For Claude, we specifically asked it to review the samples, search online for research around the optimal ranges for chestnut tissue samples, and compare that research to our results. Below is the table that Claude produced… you’ll see it pulled research from some of the same folks we sought out. Not bad, AI.
I then asked Claude to build a recommendation of what it thinks I should do to address what it noticed in the samples. Below are its summarized recommendations.
I am going to follow it’s #3 & #4 recommendations. I am not worried about the Potassium levels right now, mostly because the tree’s growth looks healthy, they’re young and pre-productive, and we applied 159 units of potassium per acre in the compost at planting (see compost analysis below at 11 tons per acre application). Not all that K is plant available. It will become available over the years following application, but we added a ton of nutrients just 2 years ago so will focus on making that plant available rather than adding more.
We’ll keep an eye on all the levels in the next round of tissue and soil samples. If they stay low in future we may need to take a more targeted action, but for now we’ll keep focusing on building the soils overall and trying to cycle the nutrients the trees need.
Cover Crops, Weeds, & Voles
Last year, voles killed >100 trees. They had free range to move and breed in the tall cover crops and then chased the water near the drip emitters down into the soil, eating tree roots as they went. This year we mowed the alleys in the spring and weed-eated the tree rows. After this spring mowing knocked the grasses and vetch back, it was really cool to see native flowers popping back up. Even in the worst soils on the farm.
In late June, we then lightly disced and drag-harrowed the rows. We try to avoid tillage as much as possible, but our rows are still very rough and we need to smooth them out before the nuts start falling in a year or two. Tilling also is another tool in the fight against voles, so worth doing, but it’s not fun to see the damage that I know we’re doing to the soil life we’re trying to build.
Speaking of rough soils… here’s a replant growing in one of the worst areas. We had to put a replant here, because the tree last year was killed by voles (sounding like a broken record!) that liked to live between the rocks.
Since planting, we’ve been fighting the consistent southwesterly wind that causes the trees to lean. To help the replants resist the wind-lean, we’ve planted them in 3-foot tubes and leaned them towards the SW. We also topped them at planting with the top bud growing towards the wind. That strategy seems to be working. Most of the replants are growing like the one below: slightly angled towards the wind, with a dominant leader and some lateral branches.
Tipping & Suckering
Many of our 2nd leaf trees however, are still leaning. The main pruning we did this past winter was topping the trees so that their top bud was angled towards the wind. This helped, but as you can see on the image below, many of these buds pushed towards the wind, and then got bend over. The black painted tip is where we pruned last year and wind direction in the photo is left to right.
Other trees are leaning pretty much from the bottom up.
We’re doing a few things to address this. The first is re-staking and tying the worst of them.
The second is tipping branches that are bending with the wind to slow down their growth and encourage a leader to form on each tree that is growing into the wind. Below is the before and after of a tree we made just one tipping cut on to encourage the wind-fighting leader to lead.
The first photo is before any cuts were made.
The second is after we tipped the leader that was heading to the right (along with the wind). I'm holding the amount we cut in the bottom right-hand of the second picture. Not a big cut, just enough to try and give the leader we want (the one heading to the top left of the picture and into the wind) a chance to gain apical dominance.
The other cuts we've made this summer were to remove suckers. Young trees love to push suckers, so we expect we'll have to do this for the next few years. Doing so requires removing the tree wraps, cutting off anything below the height we want the first scaffold to form, and putting the tubes back on.
Tree Issues
We have a few other issues popping up in addition to the wind. More voles.
Deer browse.
And odd growth on some of the replants. We’re not sure what’s going on here. The internode spacing is really tight and the color is extra red. Maybe heat and wind stress. Maybe a pest or plant hormones going in a weird direction. We’re only seeing this on a few trees (all replants) on the SE corner of the farm, so maybe a soil issue?
Let us know in the comments if any of you have ideas about what could be going on with these trees. We’d appreciate the input.
High Density Update
We’ll end this time with a straight-on side shot of our highest density “U-Pick” row. As a reminder, this is the row that is planted on 10-foot spacings, had 2-foot tall spray protectors instead of grow tubes, and we didn’t prune this past winter. The closet laterals on these trees are 12-18” apart as of mid-June. We expect many of them to touch before the end of summer. It’ll be interesting to see how this row develops and how we learn to manage it along the way.
