I'm just taking a wild guess, have you been watering the plants ?

No. Tucson water will kill people, I won't put it on my cactus for sure. I did that when our current drought started, and promptly lose a large mutated cholla. It had been looking droopy, and dummy me, I gave it some water. Now, I only use rain water for outside plants. Problem is, there is so little of it, and I don't have a harvesting system, our area is prevented from using them for some silly reason. I save what I can in a few buckets. We have a front yard that is planted with cactus, barrel and golden barrel, all around the edges. That's a lot of barrel cactus to lose. Bugs or lizards is my guess, but not sure. I need help.

they are dying from lack of water - too little water for the amount of cactus you have. Remove most of them, and thoroughly water the ones that are left at least a couple of times a year.

The lizards have nothing to do with it.

The Palo Verde - they are short-lived trees. Especially the volunteer ones.

Water plants, its the desert

Is Tucson that strict on watering plants? You guys get CAP water now, so it's not like it was years ago (all well water.)

I have to say, I'm impressed the citrus trees are thriving without water.

This post was edited by GermanStar on Fri, Aug 1, 14 at 20:52

I haven't watered the barrel and golden barrel cactus that are dying. They get plenty of rain from winter storms and summer monsoons. They are almost 40 years old. The citrus do get city water, once a month soak. Since our city went to a blend of CAP water, they have added too much chemicals to make it pass for drinking water. I believe the chemicals are what killed the mutated cholla that was 4 ft. tall. I water them all, not frequently, with rain water, when I can manage to save it. I'm so sad to see this, our yard is edged with these cactus. And almost 40 years old. It seems that the ones I covered with paper during our last hard frost are the ones affected. I'm wondering if maybe it was the dyes in the paper, it was Christmas wrapping. Our water tastes really nasty, all the chemicals they put in.

Yes, it's the chemicals from your water and wrapping paper that did this.

Hmmm. I use city water with no ill effects on my landscape. Here's a link to the annual Tucson water quality report. Page 5 has information on the CAP water they use and how they let mother nature clean it as it percolates through the soil profile before entering the aquifer. The average well depth in Tucson is 350 ft.

Here is a link that might be useful: Tucson water quality report

I won't use city water on my cactus again after killing that mutated cholla. Our water tastes bad. Our water has a nasty smell. Our water has something floating in it. It is cloudy looking. You may depend on the water report, that's up to you. I have to go by my personal experience. And I'm not the only one in our area who does not drink our tap water. Maybe you're lucky and have better quality water than we do. I had black mold grow in a pitcher of water that had been kept in the fridge. Unfortunately, the pitcher was opaque and I didn't see it. Mold in tap water doesn't inspire me to drink it. So using it on old cactus doesn't seem like a bright idea either. Lucky you, your water has better quality, maybe your pipes are newer. If I could afford a water test, believe me, I'd get one in a heartbeat.