I'd bet the problem is related more to how the rootball was handled than how the hole was dug. From your description of your father-in-law's technique, I highly doubt he bothered to check for potbound roots, and he almost certainly didn't address the issue when planting. It's also possible he wasn't careful about planting at the proper depth. At this point it's far too late to address the problem (if, as I suspect, that is the problem). Loosening the surrounding soil now will do nothing, in the long run, to resolve the problem.

Another related issue that may be of concern is tree stability. If the rootball is being slowly strangled by a potbound root system, the trees may fall unexpectedly long before they have a chance to reach maturity. It's likely that some roots are growing out into the surrounding soil, but these roots will probably be insufficient to properly support the tree at some point.

If it were me, I'd call in a knowledgeable certified arborist to examine the trees and get his opinion. Replacement (starting all over again from scratch) may be your best option, but I don't recommend that until the issues are properly diagnosed by a professional with an on-site visit.

Ugh. If you watched the planting and the roots weren't tickled as brandon outlines above, start saving for a new windbreak. I doubt such a small hole would have allowed space for expanded roots.

RTDR, especially with living things.

Dan

OK, I googled 4 the meaning of RTDR, but couldn't find 1, so...

Root Teasing Deserves Recognition?
Reliable Trees Don't Rock?
Relatives' Tasks Demand Review?

3 drippers per tree, 3 years after planting may be the reason for the poor growth, at least in part. That's likely not very much water.

More info is needed to know for certain.
1. What is the output per hour of each dripper?
2. How long do you run the system?
3. How often do you run them?

Each tree has two 1-gallon per hour and one 1/2 gallon per hour drippers on it.
I run the system for 99 minutes at a time, 3x a week. (Although I just got the timer that does it automatically. So for a long while I was going outside to turn it on -- then it would probably run 4 hours twice a week during the summer/once a week during the winter.)
Although, all the trees, including the one that's doing great are getting the same amount of water.
Thanks.

If the watering schedule was the problem, it would also affect the tree that's doing so well.

The schedule seems like too little water too often to me, but I'm not familiar with drainage of Mojave Desert compacted sand.

The problem we have here with Afghan Pine is disease from too much moisture. With an annual rainfall of 32", trees that are regularly watered ususally start withering and die between 5-10 yrs. These are desert trees that seem to work best if watered when planted and then never water them again. But that's here.

Too much water. Way too much water.

The other issue with drip irrigation is that the roots tend to hang around where the water is. If the emitters are, say, still 2' out from the trunk, there is less incentive for roots to elongate outward esp in purportedly compacted soil in the desert with little organic matter and dessicating winds.

But let's back up. There is no description of the plants save for their size. We have no way of knowing whether they are stressed or just growing slowly.

Dan

We get 4 inches of rain a year and lots of dessicating wind. There is zero organic matter other than whatever's leftover from the mix they were in when we bought them.

I added the 1/2 gallon emitters at the beginning of the summer because all the trees were getting a little brown. The water sinks in immediately -- there is no puddling at all. The ground surface is dry after about 3 hours of morning sun. The trees seem a lot healthier now than in April. In fact, they're all coming out with their first pine cones.

The "short" trees vary from 7 to 9 feet tall. The "tall" tree is about 12 feet tall.

The emitters are now about 2 1/2 feet out from the trunks. I'm going to move them out about a foot. Someone on the southwest forum also suggested gypsum.

I was thinking about taking the rototiller and chopping up the sand outside the trees' drip lines when I put the gypsum in. I'll use my fork to manually get the gypsum in closer. I'm also planning to mulch with gravel -- organic stuff just dries up and blows away.

I was also thinking about putting in some fertilzer spikes when the daytime temps get down in the 80s again. The trees have done most of their growing in the fall-winter-spring in the past.

I realize my conditions are way different than a lot of you. I appreciate everyone's advice, tho.

Thanks.

Okay, no rototilling!

I really appreciate all the advice. We have more joshua trees than we have people who know about gardening out here.

If the water sinks in right away there is likely no need for replanting, as you've removed the desert pavement and exposed the typical Mojave soil beneath. This doesn't eliminate the possibility that there are circling roots from the improper planting, but the way the soil sounds they are expanding and the trees are just behind from the poor planting job. Just a thought.

Not sure why you would need gypsum in that soil unless for a salt problem you didn't mention (get a soil test before adding any amendment and the trees are salt-tolerant). Save your money until you get a good soil test (not one from a bigbox).

The tree roots will likely be beyond the driplines by now and such activity as rototilling sounds like a bad idea unless you want to damage them. Save your money.

No fertilizer spikes as it will be wasted money (I need a standard keyboard macro for that question...).

Lastly, these trees are best with infrequent, deep watering. This is not how you are watering the tree. If your timer does not go beyond 99 mins, you may want to put that valve on another zone and run it 2-3x every two weeks or so.

Dan

Ditto what Dan said.

I would keep the drip emitters at about the dripline or maybe slightly further out. By watering more but less frequently, the exact placement of the emitters is not as critical. You'll be wetting the entire rootzone, not just attempting to wet the soil at the growing root tips.

I would strongly urge you to try to add an organic mulch. Maybe you'll have try different ones. Shredded mulch usually locks together pretty good. I've never seen any blow away, even in very strong winds, after it settles down a little.

Here where we are, we can't keep mulch down due to the winds and many do rock, which makes their yard and house hotter, but hey. At least it doesn't get in the lawn and you can always turn up the AC right?

Nonetheless, desert pavement has many of the properties of rock mulch, altho it doesn't make the trunks and lowest branches burn as much as rock mulch does. That is: protect the trunk if you choose rock mulch. And no cheesy patterns like you see in Havasu or Scottsdale!!!

Dan

Dan,

What's the difference in desert pavement and rock mulch. Isn't desert pavement rocks?

And, are you saying that shredded interlocking mulch blows away? I'm not talking bark chips. If so, you guys must have some really ferocious winds!

The gypsum was recommended by a horticulturist from New Mexico.

Desert pavement is like cement. It is composed of rocks, but there's something in the soil that binds it together like cement. I think it's also referred to as caliche.

Out in the rural desert, shredded anything becomes airborne. We get 60 - 70 mph gusts sometimes, sustained 40 mph. I could keep most of my organic mulch when I was in town because there was more to block the wind. But on the plus side, I've never, ever had to rake leaves!!

I have a view of hundreds of electric-generating windmills in the Tehachapi pass.

I'll have to try the deep watering idea.

Thanks for all the great advice!!

Desert pavement is a natural outcome of a process that creates cementation at the surface, not like caliche at all. Here on the Front Range, we often get gusts to 50 for hours. In spring 2 years ago it shredded all the lvs off of the newly planted-out (and hardened-off) veggies. All the leaves. Off all of them. Wood mulch is occasionally a projectile in the desert & rock is a logical choice (light-colored rock).

I have a hort degree and have lived in two Western arid states. As I said, I don't know why gypsum was recommended, nor do many people. Someone recommending it without seeing a soil analysis may need to re-read their soil texts and ag econ texts. IMHO.

Your trees are tough. Good choice for there and they'll likely be fine.

Dan

Too bad you can't find someone with a water injection/aeration system to fracture that soil. Holy cow, that can make a big difference on compacted soil and plant roots.

I totally agree that gypsum is a useless addition for your situation. We can't seem to get rid of the myth that it loosens compacted and/or clayey soils.

If you nay sayers lived in the desert you would understand the positive effects of adding gypsum. Gypsum affect the sodium exchange gradient and release Ca to the exchange gradient. Ca is bound to the soil particles of desert soil, al abate to varying degrees.

lol, Brandon

As I said above, perhaps there are some folk who need to re-read their uni soil & ag econ texts.

There is no need to add gypsum, as my link above explained further, unless there is excessive salt in the soil, esp true in the PedOCal region. Not knowing whether excessive salt conditions are true, one is wasting money just spreading it around hoping there is something for it to do. I hope the OP reads my link and sees the wisdom therein.

Dan

rhizo,

Where can I get that water injection system? is it like deep root injection? I want to play with one just to loosen up soil deep down and see if it works or not.

Water fracturing isn't available at retail or rental centers AIUI. You need to hire a professional, unless something has changed recently.

Dan

Dan, I just read your "nor do many people" link. I find it amazing that an article written by one person becomes "many" and that if you read the OP description of the soil and you where familiar with the soil that there is a 99% likelihood the soil has high levels of bound K and Na. I agree a soil analysis would be best but al abate that I would go with the use of Gypsum which is cheap.

Further more, the author of the article stated many conditional and qualifying statements/clauses in the recommendations and limited the conclusions to urban/suburban soils not native soil such as the desert. Next time don't use such a big brush when painting you recommendations.

Well, many know that spreading gypsum around willy-nilly is a waste of money, petz (cheap has nothing to do with anything when spending money you don't need to spend [wasteful]), and Linda merely wrote up what many know. Sorry you didn't catch that.

And sorry you didn't mention that Ca is abundant in the PedOCal region )the Ca in PedOCal) and gypsum isn't needed to release Ca, esp as the OP mentioned 'caliche'. And surely you know, having a horticultural education, that qualifying statements for such an article are the norm, else you'd spend a lot of time writing letters to authors of articles you read.

As I said, reread your soil text. The one you saved from your uni education for future use. And it is likely your ag econ text says the same thing: never spend money on a treatment that is not needed. This is not to say that a soil analysis will not find that gypsum is needed. This is to say that automagically stating that one should spread gypsum is not needed.

HTH.

Dan

"And sorry you didn't mention that Ca is abundant in the PedOCal region )the Ca in PedOCal) and gypsum isn't needed to release Ca, esp as the OP mentioned 'caliche'."

Oh so so wrong!

The Ca in PedOCal, caliche, hard pan, and by what ever other name is bound up in the Calcium Carbonate molecule which is NOT soluble in water and only slightly in weak acids. Think rocks and cement when you see Calcium Carbonate. On the other hand, hydrate of Calcium Sulfate, gypsum, is soluble in water thus make it available in the Cation ion exchange cycle.

This is my final post about this issue since further discussion is fruitless as we are apparently not understanding what each other is writing.

But desert soils seldom have excess sodium. They do have accumulated soluble salts, but sodium, as said, is seldom in excess.

It takes a professional soil teat to know for certain.

Oh yes, back to the question of why one plant of many isn't doing well.

As it turns out, each plant, even though the same kind and size when planted, is an individual. And an individual or two can have problems that others in the group don't. Among them planted too deep, or a root problem, such as girdling and/or poorly developed.

Thus, such individuals wouldn't thrive even though given the same management as all others of its kind.

Jean
who gardened for 30-some years in arid SoCal, one of the places where mistaken folk often recommended gypsum.

"Oh yes, back to the question of why one plant of many isn't doing well."

That wasn't the question/issue. All of the trees planted earlier by the father-in-law weren't doing well. And, I suspect we have diagnosed that problem about as well as possible unless new info arises.

And, I suspect we have diagnosed that problem about as well as possible unless new info arises.

Yes. And as others upthread have said, the problem does not include anything that requires gypsum to correct. That particular plant will respond to as much water as you give it, but is perfectly fine with little supplemental irrigation, which is why it is not hard to find down there.

Dan