About 6 months ago, one of my saguaros was getting too much water, it got too fat and developed horizontal slits which made it start bowing over. A professional saguaro "doctor" replanted it so it would start growing upright and the slits were treated. Looks like it healed pretty well. We were told not to water it at all. 6 months ago it looked really healthy (other than the slits) and had a nice green color. But now that we aren't watering it, it doesn't look well and it is turning red and yellow. What causes this color change, and any advice on how to care for it? I attached photos showing the colors, the slits that have been healing, and how the saguaro is still curved. Thank you!
[light box]2019-11-02/Kris602/e4355c[/lightbox]

Since you over watered at one time it will be damaged and that can't be fixed. Yellow means death to most Cactus. Leave it alone and let it be for the best results.

What does your Saguaro 'doctor' say?

The yellow and purple/red colors look like stress colors due to temperature/sun angle - now that it is Fall, going to Winter, the lower angle of the sun tends to hit sides of the cacti more than when it is summer, which can cause sun stress, but the purple I associate almost more with it getting colder. You list Phoenix as your location, but from the pictures, I would guess you are on the outskirts at significant elevation, so it may have gotten a lot cooler than it has for me here in the Tempe area which is in the middle of the urban heat island.

Are you sure you have not watered it, the soil around it looks like it saw water recently? Where I am at it has been incredibly dry since the start of summer, so I have been watering my plants including a couple of small Saguaros pretty recently even though they were both transplanted just before the summer.

How does the base feel? solid or mushy? if mushy it is all over. I would suspect it is still pretty solid.
One way to know if the plant has rerooted at its new location is to see if there is new growth, so one thing to check is to see what the top of the plant looks like. New growth is usually pretty obvious as the spines tend to have different more bright colors.

If it has new growth, water it some, is not the end of the world, but certainly do not start hosing it down. These plants are ideally adapted to the AZ desert climate, but when it has been as dry as it has been this summer/fall some extra water should not hurt them.

Very sad to see so many saguaros in Phoenix are falling right now from the intense heat spell we're under. On our street alone, six in the past week are dead from sun stress and many more nearing demise with no relief in sight.

It seems we'll lose our's soon. Is there anything that can be done once sun stress begins?

phxphun said:Very sad to see so many saguaros in Phoenix are falling right now from the intense heat spell we're under. On our street alone, six in the past week are dead from sun stress and many more nearing demise with no relief in sight.

It seems we'll lose ours soon. Is there anything that can be done once sun stress begins?

Wrap it in shade cloth

@phxphun Welcome! You might have been better off starting a new thread for this, because the previous issues was probably not due to extreme summer heat...

It has been brutal. I have had plants get burned to a crisp through shade cloth. I think it might have helped if you had done that right from the start but no one really expected it to be this bad. I have many plants on life support. I have upped my watering frequency but it has been so hot that I think many plants are just in absolute heat shock and the water is helping very little. If you drive around the Phoenix area you'd think desert cacti came only in yellow brown or crisp... except of course chollas...

They say it is supposed to cool down a bit soon, but I will believe it when I see it.

Since it has not just been hot but also so dry (I am not sure how much of the few storms that have come through you have seen), my rain gauge is at 1.2" for the last 3 months, so not nothing, but it all came in two big storms which is not enough to help, you could try giving it a few very deep waterings, just set the hose near it to a slow but steady flow and really let the water soak in, leave it on for a good while (find a flow rate that does not lead to lots of water run off), maybe give it a break to let excess water flow away and then give it some more.

It may not immediately improve its looks, but it will help it get through the summer and then in the Fall it could have a decent recovery - I have seen some ragged looking plants with incredible good looking new growth, so they can take a lot, but I think just about anything in the greater Phoenix heat island needs lots of extra irrigation this summer.

Good luck!

skopjecollection said:

Wrap it in shade cloth

Thank you for the suggestion. I may try that, but sadly it has deteriorated quickly. To the point of now having significant horizontal cracks around it's diameter.

mcvansoest said:@phxphun Welcome! You might have been better off starting a new thread for this, because the previous issues was probably not due to extreme summer heat...

It has been brutal. I have had plants get burned to a crisp through shade cloth. I think it might have helped if you had done that right from the start but no one really expected it to be this bad. I have many plants on life support. I have upped my watering frequency but it has been so hot that I think many plants are just in absolute heat shock and the water is helping very little. If you drive around the Phoenix area you'd think desert cacti came only in yellow brown or crisp... except of course chollas...

They say it is supposed to cool down a bit soon, but I will believe it when I see it.

Since it has not just been hot but also so dry (I am not sure how much of the few storms that have come through you have seen), my rain gauge is at 1.2" for the last 3 months, so not nothing, but it all came in two big storms which is not enough to help, you could try giving it a few very deep waterings, just set the hose near it to a slow but steady flow and really let the water soak in, leave it on for a good while (find a flow rate that does not lead to lots of water run off), maybe give it a break to let excess water flow away and then give it some more.

It may not immediately improve its looks, but it will help it get through the summer and then in the Fall it could have a decent recovery - I have seen some ragged looking plants with incredible good looking new growth, so they can take a lot, but I think just about anything in the greater Phoenix heat island needs lots of extra irrigation this summer.

Good luck!

Thanks mcvansoest.

I'm trying extra water, but it's really looking like our's will not survive. We're putting our house up for sale starting tomorrow and I'm afraid we're going to have to take the cactus down. Unfortunate, as it's been the highlight of our front landscaping. Based on your comment about their survival, I may wait a week, hoping for a miracle.

I've lived in Ahwatukee and loved this desert for over 30 years and have never seen anything like this. There's a desert canyon just behind our house we walk in almost every morning. It's been decimated... another two causalities just this morning, since two days ago.

phxphun said:

I've lived in Ahwatukee and loved this desert for over 30 years and have never seen anything like this. There's a desert canyon just behind our house we walk in almost every morning. It's been decimated... another two causalities just this morning, since two days ago.

It is terrible, but I think that with the temperature increase that has been happening slowly but surely in the summers, combined with the relatively long term drought conditions it is clear that the Saguaros in the area here have gone from being well within their comfort zone growing climate wise to being right on the edge with something like a summer of this to accelerate what probably has been a gradual longer term decline right to the point of no return.

That is so sad. I love the saguaros and the ocotillos that dot the hillsides if you're in the right place.

If the tops are still green or yellow, but bottoms are brown and soggy, cut the tops off and replant. They will regrow.

erosanova1 said:If the tops are still green or yellow, but bottoms are brown and soggy, cut the tops off and replant. They will regrow.

Have you done this with a Saguaro?

Just curious, because the general experience is that it is close to impossible to get Saguaros to regrow from a cutting - people have managed to keep small arms alive for multiple years and even develop some roots, but few if any have ever grown to be the giants they are supposed to be.