DH is correct (whoever DH is) drip will not create sufficient hydraulic pressure to migrate water deep enough to properly irrigate many root systems.
It's something I hear all the time from people who come by the nursery and want to know how to deal with their fruit trees, after your soils area has been hydrated it's much easier to maintain the moist levels,, flood or use a 1/4 inch soaker hose.
If you want to come by the nursery here I can show you.

Here is a link that might be useful: the place

actually, I have good success with drip getting water deep, It just happens slowly. with 1 or 2 gal/hr drip, on average, you will get 6 to 12 inches per 24 hour run, so to deep water, you need to leave it on for oh... a week or more for the first time run, then 12 hours once a week would be a good starting place. Actual tests plugs to see what the moisture is like is a great way to go.

Mary - if 24 hours gave you a foot deep, do it for another 24 hours. It's additive.

Coil a soaker hose in a spiral around the tree, from the base out to a couple of feet past the drip line and turn it on so it barely oozes out. Leave it running for a couple of days.

After you get the soil nice and moist, mulch the heck out of the area.

90 percent of the feeder roots that absorb water and nutrients are located near the drip line and beyond. Watering near the trunk is ineffective and can actually contribute to 'wind throw' or trees blowing over or leaning after strong winds.

If you use a basin, create a dike a foot or two away from the trunk to prevent water from reaching that area. It will end up looking like a donut with the trunk in the middle and your watering area the actual dough part.

You can use drip emitters or soaker tubing to water your mesquite. Just place them at the drip line and water long enough to moisten down to at least two feet (three if you can). As softmentor mentioned, this could take a very long time depending on the size of your emitters. I like to use 4 gallon-per-hour emitters and place enough around the tree so running my system for 6 hours delivers enough water. The adjustable emitters that produce little streams of water work well also as long as you don't have a problem with runoff.

A mesquite tree with a 6 foot diameter canopy needs about 30 gallons of water every two weeks - your two year old tree may be larger of course. This will increase as the tree grows. Several of my native trees (mesquite, palo verde) aren't on the drip system and I'll just let the hose trickle overnight at the drip line. If the root zone hasn't been moistened, I'll move the hose to another area and water again the next night - move the hose again if needed.

Take a look at Landscape Watering by the Numbers. On page 9 is a table that lets you know how much water to apply depending on the size of the tree.

Good luck.

Aztreelvr
certified arborist

Here is a link that might be useful: Landscape Watering by the Numbers

Thanks so much everyone. We certainly have some very helpful and knowledgable folks on this forum. We have been flooding the tree basins and will use a soaker hose in the future. I'm drip emitter challenged......everything in the yard is a long way from a water source. We need to rent a trenching machine.

@marymcp
we planted 5 mesquite saplings (5 gal bucket size) in "the back 40" of our 1+ acre property a couple of years ago - in JUNE - like a couple of idiots! Our water is so hard that soaker hoses get clogged very quickly. I made berms at the drip line for each tree which I filled religiously by hand-carrying water in 5 gallon buckets for about the first two weeks.

That got old pretty fast so then I hooked two 100 feet lengths of heavy-duty construction hose together and attached them to the faucet at the house. I ran the now-200 foot hose out to approx the middle of the area where the trees were and attached a brass 4-way splitter with individual shut-offs to the other end of the hose.

THEN, I got 4 more 50 foot garden hoses to attach to each of the feeds on the splitter and watered using the a-bit-more-than-a-dribble method. I turn on the faucet and just alternate turning the individual feeder hoses on and off all day long. Filling the basins seems to work very well since the water soaks in all around the drip line, instead of just in the little spots where the emitters are.

The trees have all done very well, they are green as can be now and looking very fat and healthy. My system is perhaps the ugliest, clunkiest, Rube Goldberg contraption you have ever seen, but it works and that just seems to be the way I roll!! :-D

Mary, It's like Vynnie said, water...water some more...water some more...water some more...test so you will know if you have been effective. All my automated watering systems come on twice, 10 minutes apart in my attempt to get the water deeper.

Hiya Mary and all,

Where does one get a soil probe? I've wanted one for years and you see it mentioned in all of the desert gardening books etc but I've never seen one for sale. I've seen probes for watering, and for applying fertilizer deep into the soil, but does anyone sell plain ol' soil probes for poking into the soil to test water penetration??

Great thread, thanks for posting it!
Take care all,
Grant

I know now Jayne, and feel like a real dufus that I didn't connect to that concept on my own. McDopey....that's me.

Grant, I have these long threaded steel poles that DH got somewhere - Mr. DumpsterDiver - they're about 6' long and I just had Butch grind a point on it. Then he marked it at 6" intervals with each 1' mark a different color. Rebar should work, you just need to grind it to a point. If you don't have the right tool to cut the point, come on over for a yard tour and we'll fix you up.

zzini - By now the trees should be able to survive without water.

Grant ... it's called 1/4 steel rod from the hardware store (not rebar, the ridges interfere), or a honking big screwdriver :) Depends on how deep you need to test.

If you use steel rod, make a 90 degree bend in it at one end for a handle.

not rebar, the ridges interfere....

Good point. and the 90° bend too. It's sometimes hard to pull the bar out.

Hah, okay, thanks for the information. Guess I'll have to make one myself. Currently I use what's basically a large 3 foot long "nail" that is used to slamming guy-wires of tree stakes deep into the ground. It does a pretty good job but not having the 90 degree bend makes it harder to get in/out. I'll see what I can come up with--thanks again!

Man alive! This deep watering is going to take a couple of weeks. I got some soaker hoses from Harbor Freight and have been rotating them around the drip line of 2 mesquites, a vitex, a fruitless olive and the shamel ash. Move the hose about every 15 minutes to a different section of the drip line, do this for 3 or 4 hours, back and forth along the two sections of the drip line. Turn the faucet off and wait overnight.

Most are still wet less than one foot down, 6" - 8" maybe. One is at one foot. The shamel ash I think, it's out front and has the most consistent watering over all. Plus I've been hitting that section with Dispur-sul since it went in the ground in the fall of 2005. Maybe that stuff works??

I've been using the 1/4" soaker hose with good success, it hooks right up with the basic drip system and hasn't pluged up in over a year

sounds like way more back and forth that you need. do one section / hose for 12 hours, then move it. After 3 times each for each hose, you should have water going deep. then repeat every week this year while the trees are still young. If you see even the slightest sign of stress, step it up to 2x per week this year.

softmentor, if I leave the soaker hose in one spot for 12 hours, there is a lake several feet out from the tree's drip line. It's caliche down under so moving the hose every couple of hours over a 12 hour period seemed to work fairly well. With the exception of the shamel ash, all the trees look fine I just cannot tell what's going on with the root system. I'll keep on with the system through this year, probably replace the shamel ash in the fall and put in 2 or 3 more trees. I have a large lot, third of an acre, and there is not much shade.

Thanks all for the conversation.