Friday, February 26, 2010

Using What I've Learned

I spent this afternoon upgrading the irrigation system.  A contractor's special,  the entire 1.3 acre lot hosts a single very long supply line governed by one timer.  In practical terms, this means that every plant which is irrigated by this system is watered for the same amount of time.  This makes organizing a xeriscape somewhat of a challenge.

Xeriscape, as I remind TBG every now and again when he sees me adding water to the desert, does not mean zero-scape.
As I have learned from painful experience, while cacti and native shrubs and trees will survive without additional water, they will not thrive.   I do have photos of these sorry specimens, but there's no reason to depress you.  Besides, every gardener knows what a disappointment a plant that was selected for a certain spot and then died in that certain spot feels like.  There's no need to spread the pain.

Anyhow, back to xeric gardening.  The basic principle is to use the available water in the most sensible way.  Since the hose bib is closest to the house, it makes sense to put the plants needing the most water closest to the source.  Hence, my moorea lilies and irises

are in the courtyard, my oasis area of my xeriscape.  They are also now in an area served by a sloping wall (aka a berm).  The run-off from the downspouts no longer pools below the rip rap (those beautiful river rocks at the bottom of the photo).  Instead, it flows naturally down the incline without spilling over the edge of the slope, and nourishes the Siberian Iris bulbs which are, for the first time since being planted in the Arizona desert, actually green and flourishing.  I'm hopeful. 

Since the idea of revamping the entire system sent TBG into a paroxysm of hysteria, I was forced to rethink and revamp and reconsider and reorganize and reconstitute my plan.  My criteria  were simple:  affordable (read: cheap) and no more than moderately strenuous.

You may wonder about that last caveat, but those who have followed the Burrow from the beginning know full well that calling the ground here soil is giving it lots more credit than it deserves.  It is unaerated.  It is packed and baked and compacted and under-nourished and has the occasional vein of caliche (do you mind if I use wikipedia as a reference?) to add to the fun.  A trowel is useless here ; my first garden purchases in Tucson were a pick axe and a pry bar.  

Kim-the-Engineer has allowed me to follow her around the Master Gardeners'  Demonstration Gardens   like a puppy dog for the last three seasons while she thought and considered and cogitated and reconsidered and organized and developed and tossed out and then finally created our irrigation system.  It was quite an education.  She thinks out loud.  It's not teaching.  It's not patronizing.  She just thinks out loud.  This is a wonderful gift to those of us who know nothing and are terrified to try.  Over the months, she has considered a variety of options, and though none of the situations exist in my home garden, the thought process turned out to be remarkably transferable.

So, using this tool

which I appropriated from G'ma and Daddooooo's garden shed when their house was sold, I began to determine the location of that one supply line.

Starting, as Kim-the-Engineer had done, with the furthest point from the timer, I pulled at the emitter and its stake and began to trench.  The points were good for breaking through the hardpan surface, and the flat side allowed me to slide gently along the top of the pvc pipe without breaking it.  I wouldn't have been surprised if I'd cut the line; it happens all too often in the Demonstration Gardens.  But I would have been aggravated, because fixing it requires finesse and I was feeling like a novice.

And so it went,  moving my kneeling pad foot by foot, doing bent-over-rows (and feeling it in my lats and deltoids the next morning), pushing aside dirt (I know, I know, I'm supposed to call it soil but I've gardened in soil and believe me, this is dirt) , creating a trench and following the black pipe across the yard.

Once I discovered where the line went, it was a fairly simple affair to attach a connector to 1/4" distribution tubing, run that line to the edge of the basin I'd created around the plant, attach an emitter, perhaps on a stake, and my work there was done.

I covered the base of the plant with medium tan bark to help retain the water, and started following the supply line again.

The trees required a different scenario.

To fully fuel the trees' roots,  the water needs to seep down 2'-3' below the surface. Emitters placed at intervals around the drip-line just didn't seem like they'd be adequate.  Instead, I opted for a  drip line emitter circle of tubing around the outer edge of the basin.   The photo shows the tubing just before I put it into the trench.  With laser-cut holes every 12", the tube provides a reliable and deep water supply for the poor, parched tree.

Palo Verdes are native to our Sonoran Desert.  They appear as volunteers randomly throughout the landscape.  Only drought tolerant flora can survive on their own, and the most prolific have adopted adaptations which often resemble death.  This fellow, for example, dealt with the stress of an extra-ordinarily dry summer coupled with a total and complete lack of attention by the gardener in charge (yes, that would be me) by dropping all its leaves.

The bark is still a lovely shade of green, and there is some new growth at the very tips, but it's definitely pissed.

And rightly so.

I hope that this irrigation adventure goes a long way to assuaging my guilt.

I'm trying to work on the project in sections, so I'm uncovering issues unrelated to the location of the supply line.  There are a few of these lonely spouting pieces of 1/4" tubing popping up in the gravel ground cover.

There are no plants anywhere near this mini-geyser, not even a weed.  But drip by drip by wasteful drip the water lands on the stones.  I put a goof plug   (yes, this is an actual item in any irrigator's toolkit... and it's probably the one most used) on the end until I decide what to do with it

Tomorrow I'll work on the next section and then the next until I'm done.  I won't say that I am ready to charge for my services, but I'm not immobilized by fear, either.  And that gives me a giant smile.

I saw my first worm in 4 years of digging here during this project and I stared, awe-struck, as he wriggled and writhed.  Earthworms mean good soil; perhaps there is hope. 
After all, my reward for all that hard work looked like this

and then this

and then this

There are many reasons to love living in Tucson.
Today was one of them.


  1. I am most impressed with your determination and ingenuity in learning how to garden in the desert. I'm also impressed with the fact that your embedded comments widget works and mine died a resentful death, something like your Palo Verdes. I might have over-watered it. Any suggestions?

  2. I've never fooled around with the Post A Comment section. There is some HTML code in the template I took off blogspot or blogger or whichever piece of the pie it was living in at the time.

    I feel your pain- my previews are now coming up in the same kind of little box that now houses your comments.

    I'd love to have the responses indented under the comments. Maybe we could ask the Elder Geek at Time Goes By to help us sort this out?

    As for the gardening - I am impressing myself with my determination... I'm not usually one for sticking with something that doesn't work the first 20 or 30 times.......

  3. Nance, will take you to the place that I can adjust the embedding of comments. Good Luck!


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