Stephanie,

A. a.is one of the few Agaves which benefit from mostly shade, particularly in very sunny areas. If it is indeed sunburn, they will grow out of it. A picture of the problem would help.

Pretty much any plant can become sunburned if conditions are right, or wrong I should say. If your agave are usually in a good place where they don't get sunburned on a normal day and you want to keep them where they are planted, you could fashion some sort of temporary greenhouse- just to keep the sun off of them directly. Here's an easy one: http://m.instructables.com/id/DIY-Greenhouse/?ALLSTEPS you'd have to make some adjustments because yours are planted in the ground, but it's a start. :) Good Luck! - Sam

Yes, that's sunburn. Those past couple of heat waves were tough. The damaged leaves cannot be repaired, but the Agaves will grow new foliage and the damaged leaves will be less and less noticeable as time passes. A good soak could stimulate some new growth.

If we get yet another heat wave you could rig some temporary shade (piece of cardbord or something). That's about all you can do.

Yes, that is definitely burn. Fortunately, A. attenuata is a very fast grower and should put this hideous phase in the r/v mirror before too long. Next time, throw some shade cloth over them as conditions dictate. Good luck!

I'm sorry, I should correct myself. I meant build a greenhouse, but instead of using plastic, use a sheet or something of that sort. Plastic would create humidity. Sorry for my error. :)

Anyone know what this is on the blue glows

Even saguaros can get sunburned if they are transplanted in a different orientation.

Is this sunburn as well?

It looks like past sunburn, yes, but as you see the plants have done quite nicely growing out of it.

@entw1 That is edema.

Ron, how do you tell the difference from this photo? And glad to see you back.

@entw1 as Gees 9b Stated, your blue glow has edema, not sunburn, which can happen with extreme temperature, humidity or light changes. Blue glows are picky.

How do I know? Unfortunately, I did this after buying 4 PERFECT 15 gal Blue Glows from the nursery, I put them in the shaded back of my suv and had the air conditioning blasting because it was a hot sunny day! I made a stop on my home too, but left the air on not wanting to scorch them. I noticed when I got home that the leaves had these smudgy lines on them that I hadn’t noticed before, and by the morning, bam, mine looked like yours. The good news is that the plant won’t die. The bad? Well, those spots don’t go away. A little paint dabbed on just the dead spots will mask the scarring until new growth covers it. Good luck and enjoy your new plants!