A learning experience: Lost 5 collected Black Spruce this June.

I live in a cold climate as well, and nearly all my spruce are collected in the Rockies. They are englemann and white spruce, so some of the nuances may be different from black spruce.

I have never had good luck collecting it Fall, as I usually get hard frosts in September, and still high daytime temperatures. I now collect in mid May to mid June, after the ground thaws, but before the Buds burst. I never bare root and put them in wood grow boxes tied down with holes drilled in the bottom.

I also can't get pumice affordably here, so I use "Qualisorb" (diatomaceous earth) from Canadian Tire to fill in the gaps. It seems to hold moisture alright, but drains well and doesn't break down in the cold. I also use chopped sphagnum as a top dressing. All my trees are dug down to the rim and covered in mulch for the winter.

Things I've tried that killed or weakened collected trees: using too organic a mix, not heeling in pots over winter, using plastic nursery pots that can change temperature too quickly, collecting in late summer, collecting in fall
 
Tycoss those trees are amazing! And thank you for the information! Canadian Tire's shipping rates to my community isn't that bad so I may look into your solution. Thanks again!
 
I reckon that's your ticket. DE however possible.

Sorce
 
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June has been rough going. Within only a few weeks of each other I lost five of my six collected Black spruce. All of the symptoms were the same. Sudden drying of the needles followed by yellowing and finally massive needle drop. It's a little heartbreaking as I was excited about them, but I need to look at this in a logical way. I obviously did something wrong. So changes must be made to how I collect and care for these trees. I'm hoping this will be a valuable learning experience. I don't believe in hiding my failures.

Here are some key points.

- All but one of the trees were collected in late fall. About a month before the first snow. The other tree was collected in early spring.
- Most of these trees had excellent root systems when they came out of the ground. None were bare rooted.
- They were planted in wooden boxes made from recycled pallet wood (not pressure treated or painted).
- The substrate for all but one was 1/4" fir bark. Good drainage and doesn't decompose quickly. One of the smaller trees was planted in pure living sphagnum (this tree had poor roots but was the last to die...).
- All trees appeared to survive winter and spring. It was only during June that they rapidly declined.
- They were watered attentively. Kept moist but not sopping wet. I also misted the foliage to maintain humidity.
- In the Fall, I had my trees on a table I built from scrap wood, but later moved them to the ground.
- They were placed on the leeward side of the house, protected from the harsh wind, and received morning sun/afternoon shade.
- Interestingly, my Tamaracks are doing just fine and pushing new needles like crazy. They were treated the same way.
- I have one Spruce left which was collected later in the season. I'll admit that I did a much better job at transplanting this one. But I'll be watching it very closely.

So, what do you think? I have a few hypotheses.

1. Collecting Spruce in late fall might have been a mistake. Since they put on most of their root growth in the fall season, I might have undone what the tree worked hard to build during the previous weeks/months.
2. Heat sensitivity. Is it true that Spruce move water much less efficiently than a Tamarack (Larch)? This coupled with root damage during collection may have prevented the Spruce from cooling themselves adequately.
3. Root damage from the cold? They appeared totally fine in the spring. However they showed no signs of new growth.
4. Too rough/aggressive with the roots + Poor anchoring. Many of my earlier trees wobbled a lot. I've since become much better at anchoring my trees.

Please let me know your thoughts.

Disclaimer: The following is not advice, but in case they're useful, here are some positions I've taken on fall collection of conifers (and also deciduous) that have served me well (you already seem to know most of these):

1. If you collect in fall and you're at least as cold as where I am (zone 8), use a heat mat to keep roots well above 0C.
2. Raising the temperature to a (24/7/all winter long) 20 to 25C is even better, and can yield outstanding success and help the tree "hit the ground running" in spring. Heat mats are so outrageously amazing at their job that I've managed to bare root a lodgepole pine yamadori and it filled a pond basket with roots without skipping a beat -- YMMV with non-pine, but still, they are magic. Given that they are so inexpensive and easy to find online, a really important part of a collectors toolkit if they live in a colder area or must collect in fall to avoid mountain snow / closed roads (or both).
3. The above points shouldn't be misinterpreted as keeping a conifer indoors, or in a space that goes above 7C during winter
4. Recover conifers in coarse pumice or coarse perlite and not in organic substrates. YMMV, but not using pumice just shifts the inevitable to later IMO. I have not had great results recovering conifers in bulk, but they may have been more air-thirsty than a spruce.
5. Trees should not move and wind cannot be a lever on the trunk. Boxes shouldn't flex at all if they need to move. If I've used an anderson flat as a recovery box for a tree, I've reinforced it with wood somewhere so that it doesn't flex. The sound of pumice undergoing shear as I lift a grow box after a few weeks of recovery is a sound I want to avoid at all costs. I will carefully slide a firm metal plate under a box and lift the plate instead of the box if that's what it takes to have no flex. They're only getting moved once or twice for urgent reasons before the growing season anyway.
6. Conifers shouldn't be watered excessively during the first few months of recovery.
7. IME, recovery is significantly quicker and feels more durable when a conifer is kept in full sun. For me, has applied equally well for pine as for subalpine fir, etc.
8. The size of recovery container should be a minimal bounding box around the volume of the root system / soil cake you extracted from the ground. Oversizing = trouble, a recovering tree doesn't cycle water out of soil very fast.

If I was to guess what went wrong for you, I would guess that things got far too cold and that the trunk levering / moving didn't help. The latter of those is easy to fix.

If you can, give heating mats a try. Even the least expensive vivosun-brand ones are used by professionals (both field growers and multiple bonsai educators) in my area and seem to work great, but if you want super heavy duty ones that can really push some watts when it gets super cold and can hold up to industrial abuse, the heavy horticultural-grade ones are great, and probably have an excellent resale value down the road in case you're concerned about budget (as would the controller/sensors).

If I was playing this game in northern Ontario/Quebec/Manitoba/Alberta, I'd probably set up heat mats and then bury the recovery boxes in a large "heat battery" of very heavy but very coarse locally-available gravel to act as a thermal reservoir during the worse sections of winter. I've done this with lava, and it works amazingly well at soaking up all those extra Watts you're paying for and keeping things toasty. To maximize the use of every single watt/bit of heat, I cluster as many trees as possible over the mats to insulate much as possible and prevent any leakage. Keep in mind that the root systems can stay toasty without waking up the canopy.
 
here's a good demo from Ryan Neil how to create a heatmat.

Start looking from 33:36

 
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MaciekA That's really great info! Thank you so much!

I think I'm sold on the idea of heat pads. But I'm going to have to wait a bit for a more permanent setup. I can definitely get my hands on some local gravel though. Should be cheap/free. I also found a website for a pumice mine out in BC. I'm going to contact them to see if I can work something out. Fingers crossed.

I would guess that things got far too cold and that the trunk levering / moving didn't help.
I've gotten much better at anchoring trees into their boxes and the surviving Spruce doesn't move at all. It's secured at 4 points with heavier wire. As of right now it's buds are swelling and turning gold/green. A good sign! Again this one was collected on June 3rd.

What's interesting is the Tamaracks all survived just fine being completely buried in snow. They are all pushing growth like crazy with no signs of slowing down. I wonder why that is? I didn't really treat them any differently... Obviously they aren't the same species. But you have to admit it's interesting to see how tolerant they are comparatively.
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MaciekA That's really great info! Thank you so much!

I think I'm sold on the idea of heat pads. But I'm going to have to wait a bit for a more permanent setup. I can definitely get my hands on some local gravel though. Should be cheap/free. I also found a website for a pumice mine out in BC. I'm going to contact them to see if I can work something out. Fingers crossed.


I've gotten much better at anchoring trees into their boxes and the surviving Spruce doesn't move at all. It's secured at 4 points with heavier wire. As of right now it's buds are swelling and turning gold/green. A good sign! Again this one was collected on June 3rd.

What's interesting is the Tamaracks all survived just fine being completely buried in snow. They are all pushing growth like crazy with no signs of slowing down. I wonder why that is? I didn't really treat them any differently... Obviously they aren't the same species. But you have to admit it's interesting to see how tolerant they are comparatively.
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It's interesting how different species of conifers respond to variations in collecting practices. I mentioned before how I don't use plastic nursery pots for spruce anymore, as I think they can heat up and cool down too quickly. I lost a wonderful semi-cascade spruce this way. At the same time, my lodgepole pines collected from the same area don't seem to mind these pots at all.
 
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Of course it may not be the pot at all. There are so many variables. My nursery pots are generally heeled in fine wood chips or mulch.
 
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Heat mats are so outrageously amazing at their job that I've managed to bare root a lodgepole pine yamadori and it filled a pond basket with roots without skipping a beat
The fact that a bare-rooted pine developed roots like that is super interesting! Does this mean that perhaps temperature matters just as much (or more) than the microbial/mycorrhizal relationship with microorganisms and the tree? OR maybe the higher temperature is what encourages the growth of these microorganisms? Just talking out my A** I guess but this is really selling me on getting a proper heat mat setup.

Still no word back from the Pumice mine.
 
The fact that a bare-rooted pine developed roots like that is super interesting! Does this mean that perhaps temperature matters just as much (or more) than the microbial/mycorrhizal relationship with microorganisms and the tree? OR maybe the higher temperature is what encourages the growth of these microorganisms? Just talking out my A** I guess but this is really selling me on getting a proper heat mat setup.

Still no word back from the Pumice mine.
If you do get word from that pumice mine, I may have to get in touch for information. I'd love to have a reliable source of the stuff.
 
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The fact that a bare-rooted pine developed roots like that is super interesting! Does this mean that perhaps temperature matters just as much (or more) than the microbial/mycorrhizal relationship with microorganisms and the tree? OR maybe the higher temperature is what encourages the growth of these microorganisms? Just talking out my A** I guess but this is really selling me on getting a proper heat mat setup.

Still no word back from the Pumice mine.

A widely-held assumption in bonsai that's usually mentioned more often in the context of repotting (moreso than collecting) goes something like this:

- Established roots: winter hardy
- Roots that've been messed with: must not reach 0C or go below that until re-established again, "protect repotted trees from frost"

"Established" in my mind has come to mean "tree has gone through a full spring-to-autumn cycle without having been messed with". Established roots head into winter loaded up with a full growing season of stored energy and thus can get close to their species' "root kill temperature" (mentioned in Hagedorn's book Bonsai Heresy, with a nice data table, in case you are looking for numbers) without actually having the roots killed.

Maybe a simplified way to look at it would be to assume that messed-with roots might now have a root kill temperature of about 0C. This is my assumption for collected and repotted trees and is why I shuffle recently-repotted trees in and out of shelter in the late winter / early spring, and why my fall-collected conifers have either followed those trees to above-0C shelter or have sat outside on heat mats. The latter combination seems to always produce a much nicer looking tree when spring arrives.

With regards to the heat mats going to 20 - 29 C, i.e. beyond just "prevent freeze" and straight into "jack up the metabolism", I don't have a deep technical explanation, but a few notable educators including my own teachers have had success with applying bottom heat and observing root growth. It's also a very common practice in propagation (see Dirr's book "The Reference Manual of Woody Plant Propagation" if you don't have a copy, really useful). If you flip through Dirr's book, you'll notice species after species (coniferous and deciduous) has improved success with root generation when using bottom heat. With regards to your questions above, bottom heating works well in squeaky-clean conditions (eg: pure perlite) so microorganisms might not be a key player, though they should wake up and do their thing as well -- I suspect it's as simple as heat -> metabolism -> growth. When I have built bottom heating setups and "plugged gaps" with random baskets of cuttings and moss, I've had aggressive moss growth and signs of soil biology wherever heat exists.

I'd be very interested in hearing your luck with collecting pinus banksiana if you can find it in your area, since this species is very closely related with lodgepole/shore pine (i.e is part of the larger contorta group) and my greatest successes with overwintering with active (i.e. hot) bottom heat have been with lodgepole.
 
@MaciekA
That was a very insightful reply and I appreciate it immensely! I will track down both of the books your mentioned. I don't have access to any Bonsai professionals up here, so information like this is extremely valuable to me! If you have any other books you'd recommend (even about general tree/plant physiology) I'd be very grateful.

Pinus Banksiana is definitely on my list of trees I want to collect, and it grows all over the place. Just the other day I spotted some really beautiful examples on a drive out of town. I took note of the spots.

I'm going to pump the brakes on collecting this season and focus my efforts on setting myself up better for spring 2023. I have one spruce that is actually doing quite well, and my Tamarack clump is pushing like a champ. I'll focus on those for now.

I've managed to source some good lumber to build a cold frame (likely a lean-to design for now). I'll heel the grow boxes into the ground for added protection. I've also managed to find a source of Pumice within the province, and will soon have 72L of it shipped to me in the next few weeks (It's hard to get things here so I opted for a larger quantity to make it worth the effort). The heat mats will be a must for my future setup, but that will have to wait until I'm a bit more settled. But I'm sold on it. I'd also like to get a proper greenhouse set up for the future. Perhaps within the next 5 years or so.

Again you've given me great information and I appreciate it very much! I'll
 
Hey man I'm way up in Canada too, just a lot west of you and not quiet as remote. So pumice might not be the easiest to find but the best mix I've found is antislip lava rock from home hardware which is kinda seasonal

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and fired clay floor absorbent, I get mine from princess auto.

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I usually do a 50/50 mix and it grows pretty decent roots

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Thanks for the info! But as I stated earlier I was finally able to find a supplier of Pumice in the province who is willing to ship to me at a reasonable rate. So I ordered 72L (about 19 gallons) of it. They also stock lava and akadama. Pretty thrilled to finally have a source.
 
@MaciekA
That was a very insightful reply and I appreciate it immensely! I will track down both of the books your mentioned. I don't have access to any Bonsai professionals up here, so information like this is extremely valuable to me! If you have any other books you'd recommend (even about general tree/plant physiology) I'd be very grateful.

Another one that has been useful for me as a roadmap for tree physiology has been Brian Capon's "Botany for Gardeners". You might find a lot of other interesting tree/plant books published by Timber Press (pun intended, I assume) if you flip through their catalog (Dirr's book is from Timber Press also).
 
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Thanks for the info! But as I stated earlier I was finally able to find a supplier of Pumice in the province who is willing to ship to me at a reasonable rate. So I ordered 72L (about 19 gallons) of it. They also stock lava and akadama. Pretty thrilled to finally have a source.
That cool, musta missed reading that. My only black spruce I collected in early June 2017. It spent the first summer in the shade behind my garage. Pulled it outta the side of a hill so it was planted leaning over but has since righted itself.

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