Photo Journal: Roots Need Air!
Back in 1st September 2020 I began a new category: “Life of a Ta-Jan” with the intent of following a new Ta-Jan as it left dormancy, budded and grew during its first season after grafting.
And then I had the idea of not only recording growth above ground, but below ground as well — and so began my troubles!
You see, I broke two cardinal rules in experimentation: one is to never have more than one variable at a time, and the other is to do some practice runs first so as to iron out unforeseen problems. I paid the price big-time as my plan was literally last-minute and rushed, with time never on my side to fine-tune anything!
I so wanted to record root growth, but how? A see-through pot of some description was the obvious first point, but then what? Growing medium itself is not transparent. I had neither the time, materials, nor expertise to set up elaborate systems such as hydroponics or aeroponics, which are still enclosed and non-transparent environments requiring workarounds to see into them anyway.
So what else does one do when dreaming up a last minute experiment, but to break the rules, cobble together some lame set-up, wing it, and hope for the best!
The Lame Set-Up
I went looking for, and found, the ‘perfect’ (!) ‘pot’ — the 30L plastic container in the photo below. The Ta-Jan didn’t exactly have a root ball, but this was a good size, I thought, for such a one to eventually grow into over a season. And how much fun it would be to watch this in real time!
Holes were drilled in the bottom for drainage, and I then potted the tree in my homemade potting mix, trying really hard to have as much of that main root flush against the container side and as visible as possible through the medium. Ha!
Roots of course like it dark, so the plan was to cover the container with black plastic that could be removed easily for observation — ideally of new roots branching out and along that see-through side. Ha!
Broken Rule No. 1: More Than One Variable
I should never have used this tree when I did. I had deliberately held it back from planting after it had broken dormancy, so there was always the risk that any future poor growth would be due to this. Adding an untested ‘pot’ to the mix was an extra variable which complicated matters and made any results less definitive.
What I should have done was set everything up over winter with a still-dormant tree, in a ‘pot’ that had previously and successfully grown another plant.
Broken Rule No. 2: No Practice Runs
If I’d have thought to set this up over winter I’d have had plenty of time to fine-tune the inevitable problems that came up, such as testing it on a non-dormant plant of similar size, and devising the best way to position/anchor the jujube tree in said ‘pot’ (that one really needed more time and testing!).
So what exactly happened?
Post-Set-up
The tree was potted up on 27th September 2020 (Day 0), and watered. I was fascinated to see the ‘pot’ drain to a container capacity-determined level as described here (and which is evident in the above photo, taken on Day 0). Everything seemed fine for a few weeks, but then I had the feeling that something wasn’t quite right. That water level never seemed to be as low, but at the same time we were experiencing many days of rain right through October — 148.5 mm for the month by our gauge! Every other pot about the place was likewise saturated, why should this one be any different?
Other distractions (otherwise known as ‘life’ I believe!) came and went, and strange as it sounds to write this now, this really wasn’t that uppermost in my mind to investigate further. But by 7th November it was very clear there was very much something wrong. The leaves appeared to be in stasis when there should have been a burst of growth going on by now. They were still a vivid green to the casual eye, but a really close inspection showed problems.
Here is the very tip of the trunk on Day 0, showing very promising new shoots developing from that mass of green buds:
And here is the same tip on Day 41, almost six weeks later. My apologies for the appalling quality of the photo, but even so out of focus it’s clear that that tip is very brown.
Here’s that same tip in profile, and the green streaks along the trunk are my scrapings looking for signs of life, as evidenced by the still green sap underneath:
Day 0 for comparison:
What Went Wrong?
Despite what I said above about introducing unnecessary variables that would complicate any conclusions, I was absolutely convinced that this was not the result of holding back planting of this tree. I always keep back a small number of trees every year for the very purpose of not planting any out until every single tree shipped out had been received and itself planted out — I call them my ’skin in the game’ trees. I can never prove it of course — which is why it so important to have as few variables as possible — but deep down I know this wasn’t the reason.
I did notice that a fair bit of water suddenly flowed out from underneath when moving the ‘pot’. At first I attributed that to the shape of the container, with its bottom above a thin-edged wall the whole thing rested on, creating a chamber between the base and the ground that could trap water. I had always observed water flowing out after watering, but what if it was waterlogged regardless?
Well, there was only one way to find out! And yes, the deeper I dug into the ‘pot’, the wetter/more mud-like the medium became, and the more it smelled of something very much deprived of oxygen. I’m not sure how clear it is from this photo, but this was one sodden smelling mass:
I let this air-dry for a while, and after mixing in some hydrated coir chip:
had a much drier, more aerated and fresher-smelling medium again!
The Root
In between resurrecting the medium, I examined the root by sequentially cutting small pieces off the end:
and examining the distal (furthest from tree) and proximal (closest to tree) ends of each of those:
Here I was looking for signs of life — if the root was waterlogged it would have been deprived of oxygen and either dead or dying, as roots need oxygen for cellular respiration just as we do.
I was certainly encouraged by the more white appearance each end had the further along the root I went, though I went back 5 cm to find this! For comparison here are the very white extreme distal tips of the same rootstock variety on another plant (I barely had to cut the ends of these to reveal white).
I submerged the root in a solution of plant-starter hormone mix — if this encouraged meristem tissue to develop and differentiate then all the better, as root growth only occurs at the tip. The tree was re-potted with the resurrected medium and watered with the hormone solution.
The Aftermath
The Ta-Jan is small and I had the idea of repotting it into a 4 L Air-Pot® container. This size is actually called a propagation tray and designed for, well, propagation and seed-raising rather than long-term growing of anything. But this root needed air and a well-drained medium for increased chances of recovery, and this container was the perfect size (as was the Ta-Jan!), designed for aeration, and I had nothing to lose.
Of course, using this very container is again another variable — should this tree survive I will never definitively know whether it was the Air-Pot®, or the tree, or both in combination, or whether simply repotting in any aerated medium in any well-draining conventional pot was all that was required.
It was repotted on 7th November, and today is the 24th November, about two and a half weeks later, or Day 58. Miserable-looking little thing isn’t it?!
Exactly as with the ‘transplant shock’ trees, the leaves have slowly browned and died:
But those ‘transplant shock’ trees looked like that too, and they have all pulled through with bright green growth coming back.
There’s still green to be seen along the trunk, so time will reveal whether this little tree pulls through too, or not! (The browner scrapes you see are older ones that are…healing?)
And maybe, just maybe, this little bud at node 2 still has life in it, though it is nothing like its former self:
Reflections
I don’t regret this going so wrong, as it’s all learning and experience whether good or bad. But no question I’d do it much better next time! Starting with bigger and more drainage holes, and testing the effectiveness of these well ahead of time. Or maybe to ditch that approach completely, and explore hydroponics as an option, but with a view to making observation non-intrusive.
I has intended for this Ta-Jan to be the 2020 blogging tree, and am hopeful that it still will be. But I do have a back-up tree in case — the very same sleepy Redlands photographed in that post which has since burst into life. Trust me, I have no special experiments planned for him!
About the Author
BSc(Hons), U.Syd. - double major in biochemistry and microbiology, with honours in microbiology
PhD, U.Syd - soil microbiology
Stumbled into IT and publishing of all things.
Discovered jujube trees and realised that perhaps I should have been an agronomist...
So I combined all the above passions and interests into this website and its blog and manuals, on which I write about botany, soil chemistry, soil microbiology and biochemistry - and yes, jujubes too!
Please help me buy a plant if you found this article interesting or useful!