AusBonsai

Disaster - came back from holidays and the person I was relying on to water my trees wasn't that reliable.

I currently have few really touch and go trees the have totally defoliated and some of the stems show the wrinkled bark of deeply dried out trees.

The trees are all deciduous and in development, in plastic squat pots and in good quality commercial potting mix for growing on.

My actions so far:

Sea sol so that any root damage is supported as best I can.

One deep soaking so that the rootball is fully rewetted

I have brought them inside into a bright bathroom, so they are out of the current heat and haven't watered them again. The mix remains moist.

On the most critically damaged tree there are no visible fresh root tips.

Results after one and a half weeks:

One tree has prolifically started to shoot and will recover. I plan to put it back outside in dappled shade under my bench for a few days until the shoots extend and then harden it off.

My desert ash (I know - the irony) has lots of buds that are sitting dormant, but none of them have shot.

Other trees aren't showing any signs of shooting. They all had smaller root balls than the recovering tree, so I figure they got drier.

My questions:

Does anyone have experience with bringing back trees from the brink that thinks I should be doing something else? I know that the lot is cast, but I want to give them the best chance possible if there is any hope of them throwing a few new buds.

One thing that I have at my disposal is bottom heat, but I'm not sure how that might help.

I know is probably just a matter of waiting and seeing, but if anyone has any concrete tips that might stack the odds in the favour of revival, please comment below.

Just don't let them dry out again if they reshoot as they will be using the last of their energy if they do.
From my experience there is nothing more you can do at this point. Its now up to the hardiness of the trees.

When I go on holidays I have an automatic watering timer setup. And the second thing I do is place them into the shadiest positions, just in case the watering system fails for some reason. I don't like to rely on people as they wont understand the significant amount of time you have invested in them and how much they mean to you.

Agree with all Rory mentions above… I would also add relying on people that aren’t experienced with trees in pots is kind of dangerous. They don’t understand what is required when watering from my experience. They water like the trees are garden trees (as in, not enough and not often enough should conditions heat up). It’s not really their fault, they just don’t have the knowledge. I wish you luck with reviving them, my fingers are crossed… I’m not sure what else you could do.

You are not the first and won't be the last to come home to dry trees. Non Bonsai people just don't understand that every day means EVERY day as so many of us have found the hard way.

You've done everything I would do for dry trees so now it is just a matter of waiting with crossed fingers. It can sometimes take weeks for some trees to show new growth and, of course, you'll need to be prepared for the possibility some may not recover at all.
I would not give up on any tree for at least 3 months after drying out.
I can't see bottom het being any use.

I would not be putting trees indoors to recover or even under the benches. Leaves that open in shaded conditions have no tolerance to sun so when you want to move them back to their permanent spot the new leaves could burn. I just let mine recover where they usually live so the new leaves are accustomed to the normal sun levels.

Thanks for the responses. I'll set them back out on the benches.

All good advice. Id add to Shibui suggestion of back on the benches that it will help dry out your potting medium between waterings. Inside is too protected and soil will stay moist for a long time with no leaves pulling water out. Drying out slightly between waterings will encourage root growth. Each time you water you suck new air into the pot giving roots fresh oxygen which is essential for their growth. Only thing I'd be careful with is any thin barked trees may get sunburnt if they get too much direct sun before they leaf out.

I also went away for a couple of days and had a neighbor for watering. And just in case I put my natives and decid in saucers as well as leaving them out just in case a bit of the rain that was forecast came.
It rained pretty much the whole week AND my neighbor watered as well (terrified of killing my plants on his watch). So when I got back my pots were absolutely soaked and could have been for days.
Still, we got to see some turtles hatching at Mon Repo and no tree deaths yet.
But there is no doubt that a timed irrigation system would be so much easier. Phew