High desert watering cycle

post by davidsantafe on Jul 4, 2017

We live just outside of Santa Fe NM and have a courtyard Lavender garden. Around the house we have a variety of trees: established pinions and shrubs with new Juniper and Russian Sage. There is no grass. The irrigation is ‘drip feed’ with varying throughput at plants (typical 0.5gpm) and trees (typical 4-6gpm). At this time of the year we water both zones for 1 hour, once a week.

Should we stay with this old ‘rainbird’ cycle, or can we do a better job with our new rachio gen 2?

I would appreciate your help

post by robertokc on Jul 5, 2017

If the former schedule works, I would stick with that. You can go with a monthly adjust. Santa Fe is a pretty barren place since nearly everyone removed grass.

post by azdavidr on Jul 5, 2017

In Phoenix, we have a great guide to our desert watering recommendations called “Water Use It Wisely”. It’s not high desert here, but certainly desert.

Maybe @sunny can comment here. She’s our big time expert, master gardener and I believe has experience with high desert and Rachio.

In case you do want to take a stab at applying the “Water Use It Wisely” recommendations with a Flex schedule check out this guide.

post by davidsantafe on Jul 5, 2017

Thanks for the input, particularly the watering guide. It seems that my landscaping guys assumed a set time to water, with seasonal change, while managing amounts with various size and numbers of emitters. That approach has 2 zones, grouping Lavender, Rosemary and such together, and the outside trees and shrubs together. We are into second year and doing OK for the most part. I was hoping to get better efficiency but will settle for easier programming and the ‘app’ for control and confirmation. The current rainbird has proved problematic with seasonal change.

post by kpontis on Jul 5, 2017

You may want to try a flex monthly schedule, which is sort of a bridge between typical fixed scheduling, and flex scheduling. A flex monthly schedule will increase/decrease durations throughout the year to account for the changes in temperature throughout the year as the seasons progress.

If it turns out that you like this type of schedule, the next step would be taking the plunge and using our flex daily schedule, which constantly measures the moisture level of each of your zones, and waters only when water is needed!

post by davidsantafe on Jul 5, 2017

Flex monthly sounds interesting.

This is what the landscaper suggested for both zones:

September, Weekly 45 minutes

October every 2 weeks for 60 minutes

November through January Monthly for 60 minutes

NO mid-January through February

Mid-March. April Monthly 90 minutes

May every 2 weeks for 60 minutes.

Then see if you need to increase to 60 minutes weekly June through August.

Can I do something like that or even treat the 2 zones separately??

post by azdavidr on Jul 5, 2017

I don’t know about Santa Fe, but in Phoenix I’ve never trusted these types of recommendations. The landscapers I’ve experienced will make blanket recommendations like this without considering the vegetation type, emitter flow rates, or maturity of your vegetation. I could be wrong and they made the recommendation specifically to your yard, but I’d be more comfortable with something like the “Water Use It Wisely” recommendations that take those factors into account.

post by sunny on Jul 6, 2017

I’m a bit late to this conversation, having just returned from northern New Mexico with a side-trip to the cool mountains of Colorado! 114° here today! Ugh. I’m going back!

@azdavidr offers some great suggestions and his precipitation rate calculator for drip is terrific! The “Water–Use It Wisely” site has some very good information.

@davidsantafe, you say the piñons are established. If that’s the case, stop watering them. Piñons are very hardy and drought tolerant. Over-watering the New Mexico state tree can kill it from root rot. These pines are native to New Mexico and a few other southwestern states and can live several hundred years. They thrive in the arid deserts and in the Santa Fe area, the average yearly precipitation is fine for an established tree. As long as Santa Fe receives the normal precipitation, the trees should be OK. If Santa Fe doesn’t receive rain, then a monthly watering will benefit the pines.

More importantly, pine needle scale has been observed around Santa Fe and those insects can cause damage to a stressed tree. If you notice evidence of the insects, then you might consider a horticultural oil, sometimes called dormant oil. Bonide is one brand that is OMRI approved. It’s basically a mineral oil that smothers the insects. I use it to control codling moth in my apple trees.

A chat with the people of Agua Fria Nursery (they are very knowledgeable and have been in Santa Fe for years) or the Santa Fe Botanical Garden would certainly be worthwhile.

post by pshyvers on Jul 6, 2017

When would you suggest backing off the water for a pinion (or a bristlecone, for which I have heard similar comments)? Planted a few of them, and they will be “established” in a year or two, but the pinions in particular are only 12" tall and I’d be more than happy to give them a little supplemental water to speed along growth, you know…

Is it really an issue of, the soil needs to be dry as a bone? Or do they just need a good solid dry-out after each watering? I certainly have seen the little pinions drooping when they are too damp for too long.

@davidsantafe, I’m on a fixed day schedule for my drip, but eventually plan on moving to flex monthly, which seems like the right fit for drip. Flex daily would be cool, and is nice for my lawn, but needs crop & emitter uniformity. Drip really counts on dialing in each plant at the emitter level. I think ET modeling dripline is perilous with limited ROI, because you will have so many different plants with different water use, root depth, and so forth.

post by sunny on Jul 7, 2017

A supplemental watering for young piñons would certainly help them off to a good start. Just remember that they are very susceptible to root rot and need to dry between watering.

Weather, of course is a big factor and depending on your location, I wouldn’t give the piñons supplemental water during the winter.

You planted bristlecones? Or am I mis-reading that post? I can’t answer questions about them. I do know that they are very, very, very slow growers and extremely susceptible to root rot. They coolest ones I saw were in the Great Basin National Park and they seem to thrive in the tough growing conditions there. One bristlecone was estimated to be 4,900 years old!

You certainly are a patient person!

post by pshyvers on Jul 7, 2017

Ok, will do my best to ensure they get to dry out. Definitely not going to supplement in winter.

These are Rocky Mountain Bristlecones, related but not the same as the famous Great Basin Bristlecone. I mention them because I had indeed heard similar things to the pinion, about root rot. They do seem to be less sensitive than I imagine the Great Basin variety is; there are several ten feet tall on the edge of the park lawn near my house, which means they get irrigated.

post by azdavidr on Jul 7, 2017

The efficiency gain and ROI was with there for me. The fact that you have so many plants of different needs on the same line is a function of the irrigation setup, exclusive of the controller program. In other words, you still have the challenge with a fixed schedule but you’re overcoming the challenge by overwatering some plants with a fixed schedule. If you have the patience to do the same with Flex it can be more efficient. I was watering my drip based shrubs every 4 or 5 days last July on Flex, and without touching the program I watered once in the months of December and January. I wouldn’t have kept up with making those changes through the fall and winter if they were in a fixed schedule.

EDIT:. An important exception is for any vegetation that you determine needs to be watered more than once per day, since Flex algorithms are limited to watering once in a 24 hour period . I have my pots on fixed for that reason.

post by abqmichaelj on Jul 10, 2017

I live down in Albuquerque and have had pretty bad luck with the flex scheduling and almost lost a bunch of plants like yours after trying Flex Monthly or Flex Daily (not sure which). With bone dry air and 100 F days, it wanted to water the bushes once every two weeks (whether, I guess, they needed it or not).

My recommendation is to use fixed interval with some reasonable interval and let Rachio adjust how long it should water each time. Then, as the year progresses, change the interval manually and adjust the duration. This would be analogous to Albuquerque’s “water by the numbers” advice for grass. ( http://www.abcwua.org/Water_by_the_Numbers.aspx ) The landscaper’s guess for how to apply that to your bushes was probably better than any advice you’ll get outside the region.

post by davidsantafe on Jul 10, 2017

Thanks Michael. My biggest concern is how often it rains downtown Santa Fe, but not here (10 miles out). On the landscaper advice has worked so far, so I will keep with their interval/duration model, at least for a while. Even doing that will be way more convenient than programming rainbird.