Droopy Dawn

[Promethius]

This is a dawn redwood I’ve had for 2-and-a-bit years. It usually is a prolific grower, growing about 1.5m per year, getting cut back at repotting. I always sterilise all tools with alcohol between trees during pruning and repotting. I have had to cut it out of a pot before.

Happier times:

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Roots at last repot:

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This year it hasn’t thrived. Several buds never took off, and branches keep dying back. They look soft / droopy / mushy as they die. In the last week it has started cycling daily: in the morning it’s bright and happy (still some sad branches though) and by evening, it’s droopy. I imagine that this is representative of a tree in desperate circumstances with limited energy reserves.

Its setup is similar to the last few years:
- Open mix (pine bark, sand, 20% pumice)
- In pot, left on soil for root escape.
- Direct sun in the morning, shade in the afternoon. Airflow probably limited in this spot - against a fence, not much breeze reaches it. Exact same spot as last year.
- organic fertiliser - three Dynamic Lifter / Blood and Bone) teabags until mid-Nov (I’ve cut back in the last 2 weeks as its health plummeted)

Morning:

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Evening:

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The only change in management this year was that I deliberately over-potted as my wife’s expecting and I may not get to repot things next year. I’ve reduced watering to compensate, but these are usually water lovers and pretty robust, I understand.

My current hypothesis is a fungal problem - I’ve moved the pot into a better-ventilated position and have it on pot feet. I’ve kept it out of the last few days’ rain. Could also be something munching the roots or an infection, I suppose?

I’ve been reluctant to try to repot or look at roots because it looks to be very touch and go - repotting seems likely to knock it off. That said, it looks doomed in any case and I’m open to trying things if anyone thinks it’d help!

[shibui]

The droopy afternoon shoots is typical of a tree that can't get enough water.
The most obvious reason is the soil is dry but trees also dehydrate when there's root problems because, even if the soil is wet the compromised roots can't take in that water.
My guess is you have some sort of root problem here. It's possible that pot is just a bit too big for the root system but could also be curl grubs eating the roots.
I understand the reluctance to repot while it is growing but the reality is that something in that soil is killing the tree. The tree is usually doomed if you DON"T repot. In similar circumstances I tend to bite the bullet and repot and a lot more have survived than have died as a result of repotting.

[TimIAm]

Have you ever done any root work? With the photo of the roots, is that how it came out of the pot or have you hosed material out of that?

I personally stopped using sand except for junipers because I also have an open mix and found that sand was settling in training pots as a single layer of just sand.

If you just pulled the tree directly out of the pot, can you imagine water is getting where it needs to be? If I have a tree where the roots turn into a ball, it's usually only the top of the soil and the sides that end up getting wet, and the mass in the middle can dry out which can then cause roots to die off. If you were to pull the tree out can you get your fingers into the center of the mix and see if it's just bone dry? If you *can't* reach the center or the center is just completely dry, you need to do some root work.

I'm interested to hear about encouraging it to escape and grow outside of the pot. I can understand that it could be done, but I'd be concerned about keeping the existing root system healthy while growth is being driven by external roots. Not sure why you wouldn't just plant it directly in the ground?

[Promethius]

Thank you both for your consideration and replies.

Neil - It’s a bit late out, but I’ve found a large tub and some Seasol, and it’s taking a late night bath for rehydration (and maybe to drown some grubs). I’ll repot tomorrow night after work. I agree that I’m out of options and to do nothing is a sentence for a slow demise. At worst I’ll get an autopsy answer!

Tim - interesting observation about sand. I’ll have to look at that. I’ve found similar with scoria - no matter how much I rinse it at potting time, there’s always a thick red rind left in the pot when next I repot.
I removed 80% of that root ball. The root growth is remarkable with these, and I nearly need a hatchet. The nebari is coming along, or at least it was. The initial growth this year was fine, so I don’t think the root pruning set it back particularly, but who knows.
The soil quality here is very poor, with hard clay under a think layer of topsoil. Not deep enough for ground growing in the back yard at least. I’ve found that when leaving the pot on the ground, the tree still fills the pot with roots including close to the trunk, where the nutrient mix and water content are richer. Then roots escape and I see a second burst of faster growth. I’ve tried to dig organic compost into the soil, this year, for what it’s worth. Maybe that attracted the grubs.

[Ryceman3]

.
I understand the reluctance to repot while it is growing but the reality is that something in that soil is killing the tree..

After reading your post @Promethius I concur with the above for what it’s worth. It feels/sounds a lot like a root issue so without attention the tree is doomed at any rate, it’s worth a look IMO.

Congrats on the upcoming mayhem BTW… nothing throws chaos into your life like a newborn!

[dansai]

Have you actually checked the moisture level in the mix of an evening? Larger pots don't equate to needing less water necessarily, especially with such an open mix. It could just be that it is drying out?? You did mention you are watering as much. How often are you watering? One thing to note too, both Pine Bark and Sand can become hydrophobic when they dry out completely so water can just go through the mix without wetting it.

[Promethius]

Thanks R3 and Dansai for your thoughts.

Have you actually checked the moisture level in the mix of an evening? Larger pots don't equate to needing less water necessarily, especially with such an open mix. It could just be that it is drying out?? You did mention you are watering as much. How often are you watering? One thing to note too, both Pine Bark and Sand can become hydrophobic when they dry out completely so water can just go through the mix without wetting it.

In spring and summer I usually water at least daily, unless the mix surface isn't drying out between waterings, increasing frequency as needed on hotter days. The mix does tend to dry out towards the end of a warmer day, but there is still some moisture 2-3cm down. I haven't noted any problems with surface run-off to suggest hydrophobia, but it's a good thought and may be happening deeper.

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I repotted before work this morning, with minimal disturbance to the roots. Although the foliage droopiness continues to worsen despite plenty of hydration in the last 36 hours, the roots looked better than expected, albeit with a lower mass than I'd expect at this point in the growing season. It may survive. A couple of worms were seen in the pot but no grubs and no rot. Interestingly, there was a lot of inorganic mix at the base of the trunk - red scoria and sand. In retrospect, I recall building a small pile to plant the trunk over. Perhaps toxicity from overabundant minerals in the scoria? Or too free-draining, contributing to drying out?

[dansai]

That trunk looks very dark. Is the bark squishy? It looks similar to a fungal infection that affects Japanese maples that many people report similar symptoms to what you have described, i.e. leaves flush out and then go droopy as though they aren't getting water. In those examples the lower trunk shows black bark. Ive had a few Japanese maple go this way. It has been proposed it is a fungal infection, possibly affecting the cambium layer so new vascular tissue isn't being created. With Japanese maples it is usually attributed to overwatering during winter. Most common outcome is eventual death. I had one JM shoot from the base, the others died. It does seem unlikely that overwatering would cause this with Swampies though. Mine stayed in water over winter at my place. Mind you my winters are very mild as we usually have a subtropical climate.

[Promethius]

That trunk looks very dark. Is the bark squishy?

In a word: yes.

I’ve been spraying for a few months with an antifungal, without much success to date. I didn’t water much over winter, but it was sitting on soil as earlier, so probably didn’t drain well in what was a reasonably wet few months.

I’ll cross my fingers but I’m not expecting much. Thanks again!

[Trimmy]

That poor thing looks really sick. I'm surprised it isn't dead yet. I wonder if planting it in the ground would help. Ground grown trees seem less prone to fungal problems.