Dead growing tip on Van den Akker weeping Alaska cedar - Ask Extension
Hi - I live in Seattle and planted 3 trees in a row in my front yard in spring 2018: a weeping Cedrus libani 'Glauca pendula' and on each side of it a...
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Dead growing tip on Van den Akker weeping Alaska cedar #662687
Asked July 10, 2020, 10:49 PM EDT
Hi - I live in Seattle and planted 3 trees in a row in my front yard in spring 2018: a weeping Cedrus libani 'Glauca pendula' and on each side of it a Cupressus nootkatensis 'Van den Akker'. The trees were already fairly tall (~15') and arrived bundled in canvas. They were planted as the nursery recommended: still in the canvas, but pulled away from the trunk and with the wire basket around the rootball removed. The local soil appears to be fairly rich and well drained. At planting, I added some compost and a small amount of fish bone meal to the holes. In spring of 2019 and 2020, I added a layer of compost (but no other fertilizer) around the base of each tree but away from the trunk, and added a ring of mulch to keep water from rushing off.
After a rough 2018 where it lost about half of its needles, the libani has rebounded and appears to be thriving. The rightmost Van den Akker also had a rough 2018 with a lot of yellowing foliage that mostly turned brown and died, but I think it is largely recovered, if not thriving. The drooping growing tip is still alive and green, though there aren't too many other branches along the uppermost 18"-24" of the tree.
The big issue is the leftmost Van den Akker. It also had a rough 2018 with a lot yellow foliage that that turned brown and eventually fell off. And in 2019 there was another bout of yellowing foliage that it seems never to have recovered from and culminated in the death of the growing tip and nearly the entire top ~24" of the tree. I am wondering with the growing tip dead, is that effectively like "topping" the tree where it will never quite grow right again? If you look at the picture of the top of the tree, there is one shoot of green in that upper portion, but everything else is brown.
Given that the other 2 trees planted at the same time and in very close proximity are doing OK to very well, it seems like the issue is likely not soil quality or something I did during planting. I think watering is the big question mark, and I never got a straight answer from the nursery whether I am under or over-watering. The first year I was watering at least every other day, and every day when it was hot. Last year, it was about every 2-3 days, and I have maintained that schedule this year as well. The soil never appears saturated even after generous watering (up to 4 gallons during very dry periods), and I also do not let it get very dry.
The tree doesn't look terrible other than the top 24" or so, but it also doesn't appear to be truly thriving either, at least based on other weeping Alaska cedars in the area. And of course, the deadwood at the top has me concerned about its long term prognosis. Wondering if there are good rules of thumb as far as how much and when to water (if different from what I'm currently doing), or perhaps the tree is lacking a key nutrient?
Pic 1: all 3 trees to show soil and proximity to each other
Pic 2: top of rightmost Van Den Akker showing a growing tip that is still green and alive
Pic 3: top of leftmost Van Dan Akker showing deadwood at top of tree including an apparently dead growing tip
Thank you,
John
King County Washington
Expert Response
A dead top like this is consistent with drought damage. The top may just not have recovered from that first year. Yes, it will grow a bit funky now. You could cut off that dead top and wait for the next highest lateral branches to turn up to form new tops and then prune off all but the dominant one. That should result in just a little zig-zag as opposed to a multi-topped tree.
I'm not a fan of keeping the burlap around the root ball. There are different opinions out there, but I think the two most solid sources are https://s3.wp.wsu.edu/uploads/sites/403/2015/03/bb-root-balls.pdf and https://forestry.usu.edu/trees-cities-towns/tree-planting/remove-packing. That did not necessarily contribute to the water issue, though. For long-term rooting quality, though, you could gently excavate around the outside of the pulled-back fabric and actually cut it away around the base of the root ball (just leaving the bottom portion. Be careful, though--if the roots have already expanded pretty far and/or intertwined with any of the fabric, I would leave it alone.
As for watering, a long, deep watering with a soaker hose every 1 - 2 weeks during hot, dry weather is what I would recommend, as opposed to frequent shallow waterings in order to encourage the tree to grow deeper roots.
Thank you so much for the thoughtful and detailed reply - this is the best information I've gotten on the issue after having talked to a lot of folks at various nurseries. I also thought leaving the burlap on wasn't a great idea, but the nursery was adamant about the issue. One detail I'm still struggling with is what constitutes a "long, deep watering" - I am thinking mostly in terms of a good target volume. I always felt like I was watering deeply (usually 4 gallons every 2-3 days) in well drained soil - and the soil never really felt like it was totally saturated afterward and I tried never to let the soil get fully dried out between waterings, but if the dead top is indicative of drought stress, I guess it still needed more water. Weirdly, the hot part of the summer is when the trees start to look a little better. It seems like coming out of our wet winter and into mid-late spring is when the trees seem to look most stressed.
At the risk of pushing my luck, I did have another question. I am wondering what this large tree is that is just on the other side of my front fence. The previous owner said western red cedar (T. plicata), but I'm pretty sure that's incorrect - the foliage on this tree seems more rounded rather than the usually flat foliage of the plicata, and the general habitat of the branches seems more upturned than in plicata. Seems like this tree is more likely something in the chamaecyparis genus or even a type of juniper, but everything I have looked up seems to have something that doesn't match this tree. I would point out that it is slightly mis-shaped due to have two other large trees growing very close to it for its entire life. I added pictures of the tree, its bark, and its foliage (though not a great one as there are no branches close to the ground).
At the risk of pushing my luck, I did have another question. I am wondering what this large tree is that is just on the other side of my front fence. The previous owner said western red cedar (T. plicata), but I'm pretty sure that's incorrect - the foliage on this tree seems more rounded rather than the usually flat foliage of the plicata, and the general habitat of the branches seems more upturned than in plicata. Seems like this tree is more likely something in the chamaecyparis genus or even a type of juniper, but everything I have looked up seems to have something that doesn't match this tree. I would point out that it is slightly mis-shaped due to have two other large trees growing very close to it for its entire life. I added pictures of the tree, its bark, and its foliage (though not a great one as there are no branches close to the ground).
Re: watering, I think the best way to gauge if it's getting enough water is to dig down 12-14 inches in the root zone of the tree. If it's bone dry, then it could use some supplemental watering. If it's saturated, it's getting too much water. A nice moist is ideal. Of course, these trees are new enough to where the root zone may not go that deep yet, in which case try to dig down as far as the roots go. Another possibility is winter damage. We had that sudden deep freeze the third week of March when trees were already coming out of dormancy that has led to damaged branch tips and such. Or this could be a delayed reaction of prior damage. Sometimes all or part of the tree may die in the late summer/early fall but then things get so wet through the winter and spring that, just like a Christmas tree in a stand of water, the damaged areas stay green until things warm up and dry out in the spring. We didn't have a particularly droughty summer last year, but we did have a particularly dry fall (it hardly rained at all in November--very unusual). This is all speculation, but often that's the best we can do for damage that appears to be caused by environmental conditions.
As for the mystery tree, I can't tell from the photos. I would need sharply focused close-up images of the top and bottom of the foliage.
I hope that helps!
