Dawn Redwood Bonsai Help - leaves drying up

[gdoss87]

Hi - Long time listener, first time caller.

I've been growing some dawn redwood bonsai from seeds - this is their second year. In the past week the leaves have started to dry up and wilt, entire branches at a time. I'm not totally sure what's causing it - I water them at least once a day, but I do know that they're very thirsty trees and maybe once isn't enough? It has been very hot here, and they do get about six hours of full mid-day sun... is that too much for seedlings? I've seen no evidence of pests/mites/creepy crawlies/etc., so I don't think it's that.

These are my first dawn redwoods so I'm not totally sure what to expect. I'm used to serissas, which turn yellow and drop leaves if you look at them the wrong way (or don't look at them at all, or walk into the room when they weren't expecting you, or really any other reasons at all).

Any help would be appreciated!

Thanks!

 

[Cmd5235]

Not sure where in Jersey you are- I’m across the river, but also have a house in south Jersey as well. I have several dawn redwood, and I have them in a tray of standing water- no wilting, no issues, great growth. I just make sure I put a mosquito dunk in with them to make the yard tolerable. Because I have several, I went to my local Ace and got a large black plastic mixing basin. Before I did this, I also got browning of foliage

 

[Deep Sea Diver]

Definitely seems to be a watering issue. Pretty much all redwoods have issues with making it through the summer in a pot.
There was no mention of the what the media was. Wouldn’t pluck the tree in standing water if it’s in potting soil unless it was in a very shallow dish. Better to heel it in the ground or a garden bed and keep the ground moist. We did this with our four redwoods, including a Dawn, drilling the sides of the big nursery pots first. The trees are all flourishing through the summer this year.

Immersing a tree in bonsai media would work better.

Good luck
DSD sends

 

[gdoss87]

Thanks for the tips! They're in bonsai soil that I mixed up from two brands. I forget the names - but it's a good mix of organic/inorganic, and it is well drained but holds onto moisture fairly well. My serissas would probably root rot just looking at the soil, but these guys were happy campers in it all last year and (so far) this year. I do not let the soil dry out between watering, and I water them until the water runs out of the pots into the trays they sit in. They aren't big trays - I'll try Cmd5235's tip to get a larger basin to let them sit in.

 

[brentwood]

Don't forget that they lose their needles in dormancy - heat stress, early dormancy, does not necessarily mean you've lost branches. Don't make rash pruning decisions based on browning in August after a hot, dry summer.

Good luck,
B

 

[Tahoebonsai]

I leave my dawn redwood in a bowl of water and it drinks it up every day and it loves it

 

[PA_Penjing]

I'm zone 7a, east coast. I think a dawn redwood planted in the ground is about the fastest growing, happiest, most bullet proof tree I've ever witnessed in my area. That being said, When moved to a pot it seems to get a little hot and dry for them. I believe they are from a fairly temperate and humid part of China. I keep mine in a very organic mix. This summer was the first year I sat it in a tub of water (bald cypress style) and it seemed to me to make the tree happy. But when I returned it to the bench after its 5 day dunk it got a mild aphid infestation. Which says to me the tree was signaling weakness and distress. I have been growing DR for over ten years now and that was the first time I ever saw pests on one. It could be that my soil is on the heavy side or the fact that it was especially hot and sunny this summer but I think I will stick to frequent waterings instead. I think dunking in water is better than nothing if you can't water multiple times, but article after article, study after study suggest trees don't love suffocating during the growing season. In nature a tree growing semi submerged is usually in oxygen rich water where as dunking a tree in a bucket very quickly depletes oxygen as the temperature rises and typically (in my experience) will lead to an anerobic stench EVEN IF I change the water every 24-48 hours.

 

[August44]

I have had a similar problem this year with a forest of 5 DR. 2 have died and 3 are left. The ones that are left are very healthy and green. No clue what happened. It might have been the shallow forest pot, but sure thought I was watering well. 100+F temps in shallow, dark brown pots, morning sun only is probably the problem with me. The problem could have been heat verses water. Maybe spagnum on top would have helped my situation.

 

[Jrmcmich]

Is it possible the tree is root bound and not getting soil saturated well? I’m not sure how often these should be repotted but mine last year did just ok and seemed to not take water that great. I repotted It this spring and there were tons of roots and kinda a mess. I did A lot of root pruning and was a bit worried I did Too much but has been fine. I wonder If roots grow so much that it gets root bound but don’t have the experience to know for sure. Just observing what I saw from last year to this year but I also Don’t know how long it had been since repotting from seller although he did say was repotted last spring but not sure if any root work was done by him or not.

 

[Deep Sea Diver]

These guys usually do not need uppotting in year two.

Redwoods caliper out in fall and next spring before the buds push will be a good time to pull, prune, add new soil and put into a larger nursery container. Would not put in bonsai media at this point.

Cheers
DSD sends

 

[gdoss87]

Yeah I don't think they need repotting, although I was going to upsize the pots next spring. I think the temperature part might be a big factor though - it has been hot, and they do get a lot of morning through early afternoon sunshine (and heat)... and I'm sure the pots warm up, not regulating temperature the way the ground would. Keeping them in deeper water will probably help moderate the temperature a bit.

 

[harshadg]

May be worthwhile for you to grab an Anderson flat and slip pot as an emergency measure and put it in a tray of water like in these photos. This was an airlayer from last year with all the new root growth visible in the tray from just a two month period since June.