 The following is a production of New Mexico State University. Scott McMahon, tree horticulturist at the Desert Botanical Garden in Phoenix demonstrates water-efficient irrigation practices for trees and shrubs. Hi Scott, I'm glad to see you're irrigating outside away from the trunk, not in the watering well. Well yes, that's what we like to do here. We like to bring the emitters away from the trunk after a period of time, so the trees' roots will reach away and search for the water in order to stabilize the tree and keep it from blowing over. When the environments like the southwest create problems with that, if you just continue to water right here in the watering well, you keep the roots right here? Yes, exactly. That's what happens. And that's a correction that people need to make after they've had their tree in the ground for a year or so. They need to keep on moving those emitter heads away from the trunk to force the roots out away from the trunk of the tree. And the implied point there is we do start with the water right where the root ball is. Yes. But then as the roots extend, we want them to grow. Here I see an emitter on the end of the line, but over here I don't see an emitter on the end of the line. Yes, what this is is a head that is right at the end of the tubing, and this kind is the one that can be cleaned out because they do occasionally clog the holes being so small. So this one can be taken apart and flushed out. This tube, on the other hand, has an extension of emitter that is buried in the ground, and this is an advantage when you have animals that come by and periodically chew on the emitter tubing. If they chew the end off of this, it's no problem. If they chew on this below the head, we have a leak, and we have a high pressure situation, so it has to be fixed. So if you've got animals doing some damage, this is a better way. If you've got clogging as a problem, this is the better way. If you've got both, you have to figure out which is your worst problem. Right. Any way you go, emitters are going to be maintained periodically. So even if your system comes on at night for convenience, what you need to do is turn it on several times a year, and you need to check all the heads and make sure they're running properly in order to get a really efficient system. And the other thing we look at here is that we have plants that aren't isolated. There are other plants here and others in the distance. So these roots are going to find their way into the other areas that are irrigated. Yes, and especially with the mesquite trees, because their roots do reach out quite a bit, and they're used to doing that in habitat. They're used to gathering large amounts of water very quickly after a rain and drawing in as much as they can, so their roots will extend way beyond the drip line in many cases. The same kind of system will work for shrubs, too, won't it? Yes, and we do have some heads installed over here on some shrubs. Now, here's an emitter that's located just outside the edge of the drip line of this shrub right here. This head has an output of one gallon per hour. This is about half the amount that comes out of a tree head, which is two gallons an hour. Okay, so you're going to put less here and run about the same time, so it's not going to soak in as deep. Yes, so you can run these on the same system as the trees. Okay, and you've got other systems here as well. Yes, if you have an area you want to raise wildflowers in, you can use sprays that are attached to an emitter line to cover a wide area in order to get your seed up for the season. That's going to give you a little more evaporation, but it gives you a better coverage. Yes, and you won't want to leave it on as long as you would say an emitter, which will be two hours or four hours. This would be on maybe 30 minutes. Just to moisten this whole shallow to get the seeds germinated. Yes. Scott, this is interesting. Thank you very much. You're very welcome. The preceding was a production of New Mexico State University. The views and opinions in this program are those of the author and do not necessarily represent the views and opinions of the NMSU Board of Regents.