Dawn Redwood Question

onlyrey

Hi,

The redwood I purchased from Brussel's is now loaded with leaves. It looks as if there is no space for any more.

The older leaves are browning at the tips. Anybody knows if this is normal for this species or if this is due to excess or deficiency of something?

Thanks very much

Attached Images

	dawn_redwood_march_2006.jpg (70.4 KB, 93 views)
	dawn_redwood_brown_leafs_march_2006.jpg (66.1 KB, 46 views)

Advertisement

Bonsai Barry

I have two dawn redwood trees, although not as old as this one. Mine haven't shown such browning until fall.

__________________
Bonsai Barry

"Our talent lies in our choices."

SiNguyen

Hi, I used to have a large Dawn Redwood bonsai many years ago, and several 25 gallon sized trees in training now. Mine all used to have this problem, especially in the warm summer months. What I have learned is that these trees are very similar to the Japanese maples, in that they are very alkali and salt sensitive, and their leaves are very delicate and easily damaged by many factors. If you have very hard tap water, then you will have this problem. The professional nurseries all have expensive water softener and purifier that they use to keep their trees looking perfectly green, (plus they don't hold onto to their trees for too long). Some people told me to water the trees very heavily in order to "flush out" the salt build ups in the soil, but this never worked for me. What I had to do was:
1. Use collected rain water for as long as possible.
2. Use 100% Kanuma soil( akadama soil for satsuki azaleas) in my potted bonsai.
3. Use a high peat moss concentrate in the potting mix for my training trees.
4. Put potted trees in the partial shade all the time, and shielded from winds.
5. Make sure the soil in the bonsai pot do not get too warm in the summer (no direct light on the pot ).
6. Fertilize well, early in Spring and Fall, and with micro nutrients because these runs out very quickly in such a small pot.
7. Most importantly, transplant the potted trees routinely every 2 or 3 years at the longest, with gentle root pruning and remove old soil and salt build-up (which you can see on the rim of the pot!).
The best thing you could do is just plant your trees directly into the ground for faster and better training (like after the intial root prune and trunk shortening) . The root base will increase in girth much faster than if they were still confined to the nursery plastic pot. The trees that I have in the ground does not have much of this leaf tip burning, just very little. If there is alot of leaf tip browning then there could be significant underlying root problem.
Good luck, hope this helps, you got to love this tree!
Si

JohnQuinn

The distribution of the problem looks very limited. Make sure your soil mix is not too wet. They respond well to thinning out. They are fairly resistant to most common problems, although hot drying winds last August took a (temporary) toll on my tree.

Here's an interesting link.

__________________
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort.
Herm Albright (1876 - 1944)

Interplast

Sivananda Center

onlyrey

There is something I didn't mention, that only came up after reading your posts.

The leaves with this problem are the largest ones, and for the most part the first ones to appear. I'm in Florida, so the winter here was very mild. However, when the first tender leaves started to appear the temperatures were in the 70's, and then they suddenly dropped to the low 40's with very dry winds for a week.

Maybe the leaves that were exposed to this lower temperature (although not freezing) and dryer climate for that week were affected. I'll check if this problem persists.

Thanks very much for the replies, I appreciate your help

Aaron_K

I have 3 dawn redwoods, all growing in screened compost for over 2 years now. They get a good soaking, and the soil is perpetually moist. I feed from leaf break to fall with a liquid chemical fertilizer as well as slow release and the trees get full sunlight throughout the growing season.

The only problem kind of similar to this is that I noticed an oranging on the leaves in irregular lines across some of the foliage. On further observations this turned out to be caused by the foliage directly above blocking the sun light from these parts, and the light deficiency turned those parts to their fall colour. However there was no withering like there appears to be in this case.

I have seen pictures of dawn redwoods growing up through the middle of ponds and lakes, with the base of the trunk completely and permanently immersed under water. Mine seem to like very moist soil, the mass of thick white roots upon re-potting being testament to that. I also live on a very chalky area, go more than 1ft into the ground and you hit solid limestone. My water is also very hard but the trees have suffered no ill effects. Perhaps this is due to the 100% organic soil??

All the best,

Aaron

__________________
Do not follow where the path may lead. Go instead where there is no path and leave a trail. - Muriel Strode

Vulpes pilum mutat, non mores!

"A fox may change its skin but never its character"

SiNguyen

Hi everyone, I agree with Aaron! Dawn Redwoods do like very wet condition, although I am not sure they naturally grow in swamps like bald cypress. They will wilt and burn very quickly if dried out too much in between watering, but that's why the lime and salt build up is especially quick because of the heavy watering! They definitely don't like dry winds, hot or cold, especially when putting out new shoots. I think they do better in slightly more acid condition too, sort of like maples and azaleas, but that's just my experience. In the shallow bonsai pot, the root can get too hot for this tree if it is exposed to mid day sun, especially for the young roots on the surface or those poking through the bottom drain holes. This is one reason why Montezuma cypress and bald cypress do really well sitting in water tray, its not just the humidity but the temparature of the root ball too. Maples too, as long as it is not soaking wet.
Thanks John, for the great link to this tree's botanical history.
Good luck to Onlyrey too, you have a very nice bonsai, and good price too! I am going to get one from Brussels if they are still same priced.
Si, in Southern CA.