Wood chips as a mulch could aid greatly in maintaining soil moisture levels, as would the proper grass growing in that orchard. Most all of the orchards around here have grass growing around the trees, although one misguided person I know that has 10 acres of Black Walnuts keeps that field clean of any growth except the trees and has already seen a problem with soil moisture levels.

kimmsr,

Thank you. That was how I was taught to handle the weeds, disc, disc and more disc.

I'm learning more as I read and work in the orchard.

Thanks for the help

Fred,
Wood chips will maintain moisture very well if you have them thick enough. But consider the difficulty when it comes time to clean up fallen leaves or what it will be like when you want to add somthing to the soil under your canopies. I suppose time is a consideration. I prefer mulches that are easily moved and removed. If you decide to use the chips, consider placing a cloth under the chips so you can easily remove them. Also, once you put the chips down, try not to walk on them.
Brass

I heard about a pecan grower north of San Antonio who has several feet of mulch piled between his rows. He provides no irrigation to his trees during the year.

You have to be careful that you do not cover up the root flare on trees. That's why this fellow mulched between the trees.

The leaves from trees provide an enormous amount of food to the soil bacteria that provide the necessary nutrients to the trees so there is no good reason to "clean up" those fallen leaves every year. Leave the leaves where they fall.

Wood chips are high in carbon and will draw nitrogen from the soil in their effort to decompose. Grass clippings are high in nitrogen. You might try a layer of grass clippings covered with wood chips -- and you will have a composting situation that should move more quickly toward humus and soil moisture conservation at the same time.

The soloution to your no-call-back from the University of California: call the Master Gardeners in Los Angeles if you don't have a MG program in your county. The California Master Gardener program works under the auspicies of UC Davis. The MGs are charged by UC with solving home garden and orchard questions. They interface with the country cooperative extension which is usually directed by a UC agriculture person. Ask for a master gardener with orchard experience when you call their hot line or ask for the MG coordinator and tell her you need help.

Here is a link that might be useful: HarvestToTable.com

Fred,
Are your trees young? Do your trees have dense canopies?

You might read the post I made about the Kaoli Clay where I wrote about this clay being used on trees. The product being used is called Surround WP. This product has the ability to protect trees from the Sun's UV Rays while photosynthesis is not affected (among other reasons). Do you have Leaf Miners in your area? As I recall the Arizona heat -- the insect problems were very different from where I'm at now (Georgia).

About falling leaves under a citrus tree. A cardinal rule is to keep the area clean under a citrus tree. That's unless there are no insects or disease possibilities. I used to use mulch under my citrus trees, but I also liked the idea that I could replace the old mulch with fresh mulch for insect and disease reasons. Cleaning up fallen leaves was so time consumming. I found it necessary to mulch under the young trees because the canopies were not dense enough to shade the soil beneath them and the heat here is so intense that I was watering every day (it seemed). The older and bigger the trees grew the bigger the canopies became and moisture maintenance concerns became less worrisome. I kept pine needles under my trees until I noticed that too many feeding roots were too near the surface. I don't recall how long it was after I removed the mulch, but the feeder roots began growing deeper into the soil. That is what you want -- you want your roots growing deep.

Getting a handle on the watering needs, how often, etc. is something that you have to get a 'feel' for.
Hope I've helped.
Brass

Wood chips are high in carbon and will draw nitrogen from the soil in their effort to decompose.

This is true when the wood chips are buried in the ground. If you mulch with wood chips on top of the soil, the fungi that decompose the wood get their nitrogen from the air.

About falling leaves under a citrus tree. A cardinal rule is to keep the area clean under a citrus tree.

We don't know that this is citrus. I doubt it is if it's in the high desert. It gets too darned cold for citrus. But to glom onto this issue, (1) citrus trees rarely lose leaves, and (2) I walked through orange groves for 12 years growing up and don't remember any particular efforts to keep the area under the trees clear. That was awhile ago. Is there some new(er) theory on that? I have a lemon and an orange now. I've been using chives under the trees to warn me when the soil was getting dry.

Let me put this into a perspective...the citrus industry is loosing millions and their trees too because of a couple diseases that have everything to do with a couple insects. Whole groves are being abandoned. I could go on and on. I have two Clementine trees that have the Alternari disease. I'm doing all that I know might help them and they probably will come out this next fall if they don't show signs of recovering by July. Do they loose leaves? Especially in the spring I will rake up a five gallon container every day from the two trees. The rest of the citrus are in good condition. When the frost burn leaves and that does happen, the leaves will eventually fall. Leaf Miners ruin leaves and eventually those leaves fall. There are other reasons leaves will fall.

I've decided to grow nasturtiums and maybe marigolds under the trees and maybe some beans too -- probably outside the drip line.

Just today I ordered Surround WP -- that's the Kaoli Clay that Julianne wrote about. I will spray that on the trees as soon as I see any new growth. It's the new growth that the bad insects like.
Brass

Hey Brass,
That's too bad about your citrus. I apologize to the OP and readers for asking a question about citrus in the middle of a mulch discussion.

David,
Thanks.
I didn't stop to think that Fred wasn't talking about citrus trees. Mentioning the desert, I just related to the lemon trees a neighbor grew in Western center of Arizona. The entire area where his lemons trees were planted was gravel. He had an irrigation system. His trees were huge, healthy and old. I don't recall any leaves on the gravel, no weeds, not anything -- just immaculate. The Colorado River wasn't very far away -- that probably had something to do with moisture deep in the sand. High Calcium in the ground too. As I recall, there were no flying insects. The only insect I ever saw were ants. (what am I doing here)

If I were growing citrus trees in Ohio I could mulch all I wanted. That's because Ohio doesn't have the variety of insects and disease that is found in Florida and Georgia. Everything is relative.
Brass

"That's because Ohio doesn't have the variety of insects and disease that is found in Florida and Georgia."
That is not necessarily true and it depends on the time of year. Right now there are very few insects active, outside, but in August there will be as many as Florida and Georgia has.

A clean grove is a healthy grove .
That is the rule that us citrus growers live by here in Florida .
Any tree - except citrus - might enjoy mulch .
Just be sure to keep it far away from the trunk to avoid rot .
Fungus will take any opportunity to invade a trunk or root .
Good luck fredder with your trees .

Why is this suddenly a citrus discussion?