Curious problems with Chinese elm and Dawn redwood. (Drop of leafs in summer and dry tips)

Hello everyone, in order to lay it down in a less complicated way i'll explain the problems and info on their history and then what I think might be the problem. Please give me input on what you might think the problem is.

I moved houses and had to re position all my plants, both used to get west southern light with more than 8 hours of direct light (Im in the northern hemisphere) and even though it seems like a lot they both enjoyed it for 4 years especially the chinese elm, but since i moved i had to put them in an area that gets about 4 hours of direct eastern sunlight.

After a while from the move :

-Chinese elm- The chinese elm started dropping leaves first it started slow then it dropped almost like how it drops leaves in fall but i didnt panic as much since there was a loooot of new buds growing on all the branches. But after they grew i noticed that the leaves are 3 times the size of
the older ones and are much brighter green then i noticed some of the new buds died off and some new leaves fell again but there is still growth
here and there. Its like the plant is trying its hardest to grow but they keep falling.
 
Now the current situation is a good amount of long new shoots and alot of buds dead and alive and in one area of the plant it seems more baren than the other areas with a greater amount of dead buds.

Personally i think the only problems i can see my plants facing are -extreme heat since this summer is abnormally hot or the sudden decrease in  sunlight or requires a repotting (it hasn't been repotted in a long time) or some pest inside the soil.

-Dawn redwood- Same situation (Was moved from one place to another) But this one has at the end of every branch dry tips and when i cut them off new shoots grow for a while before there tips to dry off and in some areas new shoots dry directly without reaching a good length.

This one seems a lot less serious than the elms and i think it might just be heat.


Please I would appreciate your opinion and help especially with the elm, its one of my favorite plants. Thanks a lot.

I have a Dawn Redwood that also had dry tips. I had moved it from the porch to the yard tables. It also had Japanese Beetles around the same time. I trimmed off the worst looking foliage ,and it looks fine now, about two months later. It's slightly shadier in the yard where it is now. I just got this tree last fall, and shortened the trunk this spring. the drying happened well after the tree recovered from the trunk reduction.
So, I don't have a reason to suggest, just similar experience. Don't know about the Ch. Elm.

Thank you for your reply! I seeee I dont think there is much in common other than a decrease in the amount of light it gets but I don't see how that could cause dry tips. Maybe its just overall stress ?

Dawn redwood need shade and plenty of water. If they dry out or get sunburned the tips and indeed all the leaves will dry and drop off. If the new shoots do the same you have to protect it much more from the sun.

In the ground they have less of a problem as their growth pattern changes compared to in a pot. They can tolerate more sun in the ground but they are very thirsty. A good trick is to put the pot onto the ground and press it firmly into the soil. A few roots will grow out the pot into the ground and this helps protect the tree if you forget to water it.

Also, small trees are likely to lose their leaves quite quickly.

The good news is that they usually recover quite quickly. This late in the season make sure you protect them well as they start to go dormant so that there is no further leaf loss due to sunburn or dry pots. In spring they will bud out nicely, but you will probably lose a few branches.

I know this from experience - did it myself a few times.

Good luck!

I concur with BrendanR.  Dawn Redwood can be happy even if only in high canopy shade and is hard to keep wet enough in full sun.  The tender, immature growing tips are the first to be cut off from moisture is case of emergency like a missed watering on a high-transpiration day.

The Elm wants full sun.  Four hours Eastern sun is pleasant enough for lots of part-sun plants, but it's not full sun by any standard.  Individual leafs grow to some size which provides enough sun to do all the photosynthesizing programed into that variety of plant.  The size of the surface and the amount of chlorophyll contained is a function of how well the individual leaf has attained as close to the capacity as possible:  the leaf stops expanding (as in adding new cells at the growing edge) as soon as it has reached the programed chlorophyll capacity.  So, the leaf grows to its upper size limit only if the chlorophyll capacity isn't up to snuff.  Lighter green is less chlorophyll.

Fertilizing will help get greener leaves with the proviso that you do so as the buds are expanding.  Doing so after the fact may be helpful to the tree, but the leaves will be whatever color, based upon the conditions that existed as they grew to maturity.  Unfortunately, substituting fertilizer for proper light levels doesn't work, the leaves may be greener, but will still be striving to accomplish photosynthesizing at programed levels, requiring a bigger leaf.

We are all hostage to our environment.  In the north we can grow tropicals in greenhouses, but southerners can't grow cool zone plants.  Tropical flowers have washed-out colors in the north, but that's better than nothing.  You just need to buy more Azaleas and Yews and Japanese Maples and Cypress, -a whole new world of plants.