Drought stricken trees (need arborist HELP!!)

[ijhutch]

OK, I blew it. I have 10 arborvitae trees that are about 20 feet tall (they are screen trees in the backyard) and they haven't been regularly watered in 2 years now. I am finally getting the in-ground watering system back online so now I have water going to them again. Note that I have full access to the base of them as we ripped out juniper bushes that were living below them.

However, I need a plan to bring these guys back to their former glory. So here's my list of problems/issues. Any advice, particularly from an arborist, would be helpful.

1. 4 of them already are about a third brown (leaf wise).
2. 2 others are splaying--they basically are no longer holding their shape. They are also exhibiting the little white ball thingies which further weight down the ends of the branches. They are splaying to the point where they are essentially horizontal (they used to be vertical).
3. The ground/earth is very hard and clay-ee (this may be a result of me not watering it in so long, however). Typical Phoenix ground.

What I've done so far is remove all the old landscape plastic around them. I've also tried to dig out a well so that when the burblers come on, the water doesn't just drain away from the tree. But how far out do the roots typically go from the trunk (in this harder soil)? Also, how do I tell if the tree can recover or not? Can I wrap the splaying trees in such a way so that they can regain their shape and strength? How much water should I be giving them if they were healthy (and how often)? How much water should I be giving them now (and how often)?

We're in the 110+ degree part of our summer and I need to help these poor guys out.

I can post pics if it would help.

Any constructive advice would be appreciated.

Thanks.

* Ian *

 

[Sprig]

Hi Ian, welcome to AS! I am not an arborist but did some hunting around on info on arborvitae (American variety in particular) because I didn't know what they were (related to junipers and cedars btw). Water the poor things first and foremost! They are fairly drought resistant trees growing up to around 40ft and don't seem to mind clay-ish soil. They are slow growing and have shallow root systems. Parts do brown out but according to the sites I checked they do recover well and they will stand light shaping once in a while (not so much the Japanese variety though).
I think if they are established well that regular once a week watering and a couple of inches of mulch around the bases to the drip line (to help retain moisture during the hot weather as well as add nutrients) would help to bring them back to their former glory. I am sure there will be other opinions on this too. Good luck!

 

[treeseer]

I can post pics if it would help.

Any constructive advice would be appreciated.

Post the pics here if you want, but you need a good arborist on site. Try John Eisenhower with Integrity Tree Svc.

 

[Ekka]

Oh, those trees.

We call them Thuja's over here.

We also have been in a serious drought and it's always warm to hot here.

Those guys don't do too well here in those conditions.

I'd say they're more suited to the typical mediteranian climate of cold wet winters and hot dry summers.

Over here our summers are wet and winters are dry.

Anyway, enough of the BS. We have cut down plenty that have died from drought. The browning tips, then half the tree and so on. Having ground away a lot of stumps I can say that they are shallow rooted. Roots are close to the surface and easily burnt or dried out.

So, like the guys above said, water and mulch, mulching would be the most important and the larger the mulch circle the better, just keep away from the trunk by 6" or so.

Be careful not to overwater and bog them either, this is a balancing act, it needs moisture not a bog.

I wouldn't suggest any pruning or shaping till they stabilize, wounds = more problems, when they get some vigour back then go for it.

The white things you are on about, if they are what we see here it's a aphid style bug, spray them with appropriate chemical from any nursery.

Also, sometimes they get a whitish fungus thing here, more so in our humid times, spray with copper based fungicide. Same if the lower branches are the ones browning off not the top, that's a blight type thing, could be Keithia blight.

Pics would be good.

 

[ijhutch]

Phoenix, Arizona summers (we've seen 115 degrees so far).

What I believe to be the arborvita problems:

1. somewhat drought stricken (over 2-3 years, not getting water like it used to due to the irrigation system becoming inoperable)--4 have leaves that are a third brown

2. drooping/splaying (2 have lost their shape/structure)

3. little white balls being produced, further causing drooping/splaying due to additional weight

4. beetles...lots of them (pics below). I think that they start out small and black with a brilliant blue marking on them. The brilliant blue may become red (but they are still black overall) as they reach adolesence. Then they may become kind of brown and red in adulthood. And then all brownish by old age. Now I am ASSUMING here that these beetles are all the same, but they may be four different kinds!? They are all over the ground and sometimes all over the trees.

I cleared out a well (as best I could) around each plant, but it only goes out about half way to the drip line of the trees (3-4 feet well, whereas the tree limbs go out a good 8 feet in radius).

I have since got the irrigation system back online (within the last month). I am currently watering every other day for about 20 minutes, sending a good couple inches of water into the well around the tree. The burblers are right next to the trunks. They come on at 2am.


So, I hired a certified arborist named Troy Rock (listed on the International Society of Arboriculture website) for $75 at Al's Trees (www.alstree.com) to come out and look at them. This is what he said...
a. Water the trees once every 7 to 10 days in the summertime for 4 to 6 hours using a soaker hose. Water them once per month in the winter time. (again, slow and deep).
b. Keep water away from the trunk/root ball (bubblers are in a bad spot being next to the trunk). Don't soak the ground in the first 3-4 feet around the tree as this will promote root ball rot and cause your tree to die and fall over in the monsoon windstorms we get. Instead, the root system in nature goes out nearly twice as far as the drip line. So water outside 3-4 feet around the tree to about 1.5 times the drip line with the soaker hose (as that is where the roots are that are actively gathering the water/nutrients).
c. Deep root fertilization immediately. They brew up some special organic mixture involving fish and seaweed on Mondays and then do this fertilization Tuesdays through Fridays. This should be done yearly and now is a good time because the trees are sucking up lots of water in our heat.
d. drooping/splaying cannot be corrected by tying it back, etc., per se. It needs to be structurally trimmed, but during the winter months (November through March) as trimming now during the summer would cause wounds that would hurt the trees more.
e. little white balls indicate that it is a male arborvita. Hence that is why some of my trees have them, some of them don't (the female ones).
f. he had no idea about the beetles and recommended I take a sample in to a local nursery. He further said that root borers are the big problem around here and that they normally don't attack pine type trees (and he saw no evidence of it).


So, does this guy know what he is talking about?
== The watering advice seems sound.
== I've heard differing opinions about deep root fertilization [http://www.arboristsite.com/archive/index.php/t-1596.html] ($225 for first tree, $75 for each additional or something like that--$1200 for all 13 trees) which he says should be done yearly. He was really selling me hard on its benefits and how he does it to his trees at home.
== NOT saving the drooping branches, but removing them in winter
== Male/female trees (re: producing white balls or not)?
== Not knowing harmful beetles?

I don't know what to do. Anyone have any useful/accurate advice?

* Ian *

 

[Ekka]

Well what a fantastic job you've done of the pics and explanation.

I would be anti fertilization at this point.

I would recommend that you treat the area with fish/seaweed type of stuff (or a proper mycorhizal fert)along with a soil wetting agent to stop it become hydrophobic.

The last thing you need stressed bent trees doing is growing more.

Now that leaves the bugs. No bugs is better. And bugs breed. Most will have eggs and larvae that will eat something, most likely the tree/bark/cambium etc.

I would suggest a basal drench but have no idea what chemicals you have over there. Here I would use Confidor at triple the prescribed rate (of foliar spray) and drench the ground. It's systemic so the plant takes it up and anything eating it should drop dead.

I have no idea about the white cones and have never seen that. I also doubt that there's male and female. In fact my research shoots that theory down.

http://www.ohiodnr.com/forestry/trees/arborvitae.htm

Also, in those close up pics of the white cones I noticed the branchlets have white powdery mildew. I would suggest trying to deal with that. Take a sample to the nursery and see what they have, you dont really want to apply hort oil in that heat, perhaps a copper based spray.

 

[Kneejerk Bombas]

On the cones:
http://home.att.net/~larvalbugrex/conifers.html

On the fertilizing:
If you want to use something, these "compost teas" are pretty popular. It's basically liquid compost. The advantage over solid compost is that because it's a liquid, it can penetrate the soil.
I'd want to know how much nitrogen it has. As Ekka points out, you don't want nitrogen. Don't apply more than 1 pound per 1000 square feet. Which brings up a problem with homemade compost teas, how do you know how much nitrogen is in it?
$1200 to fertilize the trees is crazy expensive.

On the bugs:
Many arborists tend to only learn insects that directly affect trees, then when asked about the ones that don't injure trees, they say, "Uhh, I don't know."
The one little bug looks like a Stink Beetle or Boxelder Beetle, not harmful to trees, the other one...uhh, I don't know.
I'm from Wisconsin so guessing your insects will only make me look dumber.

On the drooping:
I take this on one plant at a time, and one branch at a time.
Light trimming on the tips might bring some back up. Complete limb removal might take care of the really bad ones. Some could be tied together. Some could be left alone.
The drooping may be a survival tactic. When these arborvitae bend over and touch the ground, they can re-root and start a new tree. As they bend over they also increase in size and open up new areas for foliage to grow.
Up here they bend like this under the weight of heavy snow. Sometimes they just straighten up all by themselves, sometimes they get tied back up temporarily, or pruned back.

 

[Ekka]

Mike, what's the deal with those white cones? I didn't really find much on it.

 

[ijhutch]

The white cones are actually bluish/green (but very light). They are normal for Thuja Orientalis
See:
http://www.floridata.com/ref/P/plat_ori.cfm
http://ag.arizona.edu/pima/gardening/aridplants/Platycladus_orientalis.html
http://www.hort.uconn.edu/Plants/p/plaori/plaori1.html
http://en.wikipedia.org/wiki/Platycladus

And thanks for responding, Ekka.

* ijhutch *

 

[Sprig]

I am just addressing the white powdery mildew thing here, we have experienced this on numerous types of trees and plants and have been recc'ed to use 'Neeng Oil' (sp sic) @ 1 tbsp per gallon of warm water, then spray in the late evening or early morning, repeating after 8-10 days. I am treating several plants as well as a small 2yr old apple tree as of a couple of days ago, will see how it goes and post results. The only other fairly environmentally friendly option I know of is a mild sulfur dilution sprayed on out of direct sunlight. Some more advice on this topic would be quite welcome White powdery mildew is a real pita and once it gets it there is hard to control and eradicate.



Serge