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Thanks!

 The road to optimism is paved with gratitude.  Today is a holiday dedicated to gratitude. Gratitude for the garden, For simple pleasures, like just baking a loaf of bread,  For loved ones most of all! Happy Thanksgiving, with optimistic hope 2021 is much better than 2020.

Reading Agave Leaves

What is it saying?  

If you are not familiar with Agaves, it might seem they don't change all that much, but lighting conditions affect them as much as any other plant.  For example...
Here's a small Agave parryi truncata grown all its life in full sun:
  This is also an Agave parryi truncata of the same size and age as the first.  Note the elongation of the outer (oldest) leaves:
 Why does it look so different?  Because it was covered up by a mass of Cistanthe grandiflora.  It was growing in darkness.  The newest, innermost leaves resemble the previous Agave, because this plant has been back in the light for several months.  In low light levels, the leaves elongate and flatten out so they and the plant's central growing point can maximize what light they receive.  

Here's Agave ellemetiana, which doesn't require nearly the sun that A. parryi does, but it displays the flattened posture of an Agave that would like more light.
Same thing with this A. gypsophila.  The rose that has shaded it was described as "compact".  Hah!
Another example:  Agave pygmeae 'Dragon Toes' was shaded out by an oak tree.  Note that while the newest leaves at the center of the plant are vertical, the oldest leaves are horizontal, in an attempt to gain more light exposure.  Note also that there is no curl at the sides of the leaves--they are quite flat--again, to maximize light exposure. 

From under lit to over lit.  Here's a mild case of sunburn on an Agave guiengola.  If the damage is superficial, the bleached area will gradually green up again.  More severe damage is permanent.
Slightly more sun damage and some dessication on this A. gypsophila 'Ivory Curls'--pinkness and wrinkles.  In addition, the leaves are curling inward to reduce their sun exposure.  Time to water.
Here is an Agave at the Desert Museum in Tucson, Arizona.  Permanent sun damage to those oldest leaves, and a plant grown "hard"--in extreme conditions.  Note also that the leaves are upright, not flattened out:  no additional sun exposure desired. 
 photo agave9926_zpse1ee7419.jpg
This Agave ocahui suffered damage at some point, though it has  recovered, because the central (newest) growth looks healthy and in excellent shape--no brown tips.  Perhaps it was planted in summer heat, or it got insufficient water when working to establish itself.
 Here is a more subtle difference--'Joe Hoak' in full sun is upright.  Compare the way the central growing point is surrounded by leaves with the form of the shaded A. ellemetiana:
 In morning sun and afternoon shade, 'Joe' flattens out slightly:
Here's 'Joe' stressed by moving from a mostly shady nursery bed to its all-day-sunshine permanent home.  The leaves are folding in on themselves, and they are also quite thin in texture--not fully hydrated:
I should probably shade this 'Joe' for a few weeks, until the root system recovers and begins to grow again, to avoid damage.  Two commenters kindly reminded me that all plants moved from shady conditions to fully sunny ones need gradual introduction to the sun to avoid stress.
Stressing:  the "taco fold"
 There, that's better!
Here's another example of a heat/drought/sun stressed Agave, Agave sebastiana.  Note the "taco fold" of the leaves and drying out of the leaf tips. The plant is trying to protect itself and conserve moisture.
 Not a sunlight problem, but Agave americana 'Medio Picta Alba' has a tendency to get brown marks from water sitting on the leaves.  Best to avoid water sitting in the leaves by planting at an angle, so that water drains, or by avoiding overhead watering.  
I have no examples to offer of rot, edema, bacterial/fungal infections, or freeze damage--Agaves like it here--so my leaf-reading is limited, but the effects of light are interesting.   

Keep in mind that many Agaves are native to higher elevations and are found in open pine and oak woodlands.  That means cooler nights, somewhat cooler temperatures, partial shade, and excellent drainage.  There are relatively few Agaves native to the extreme low desert conditions of areas like Phoenix or Palm Springs with summer temperatures over 100F (38 C) for weeks at a time.  A few Agaves, like Agave attenuata or A. ellemeetiana, are nearly tropical in that they can take significant shade, and regular water (given good draining soil). 

So, after seeing what light can do, Test yourself:  what's wrong with this 'Snow Glow'? 
 Nothing.  Absolutely nothing.

Comments

  1. Agaves 101. Very instructive course. I shall now look at my agaves more knowingly and therefore get more enjoyment out of them.

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  2. The leaves can tell you a lot about how the plant is coping with its environment, very clever plants. The Agave Ellemetiana and Joe Hoak are beautiful plants, so too Snow Glow.
    xoxoxo ♡

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    1. They are fascinating in their response to the sun, sensitive and aware. We share the planet with marvelous living things.

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  3. Poignant...especially the last two images when it's easy enough to overthink something

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    1. Well, my problem tends to be underthinking!

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  4. Thanks for the lessons in Agave leaf-reading. I have some Agave americana pups that are not doing well, I think maybe they're not getting enough water. I need to remember not to fall into the trap of thinking they never need water.

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    1. They can take quite a bit if it is not too cold.

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  5. We should have teamed up and both posted on this topic at the same time. After all I have examples of all the uglies you mention: rot, edema, bacterial/fungal infections, and freeze damage. Thankfully not all going on in my garden right now, but over the years.

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  6. Thanks. Very enlightening post. Snow Glow is AWESOME. MUST HAVE. GOTTA HAVE. OHHHHHHMY

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  7. Great post! My biggest mistake, generally speaking, is not giving new acquisitions (many of which aren't used to full sun) enough time to acclimate to their new spot. Not such a problem at this time of year (yet) but definitely in the summer. I've had my fair share of burned agave leaves to deal with!

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    1. So much easier to plant them in late fall--but it isn't always possible--and then we get a terrible late fall heat wave...

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  8. Maybe if I can pick up on some of these subtle hints I might be able to avoid the sudden death syndrome (guess it's not really so sudden).

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    1. Being very observant--look what it did for Sherlock Holmes.

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  9. The takeaway lesson is....I need more pretty agaves like Snow Glow and Joe Hoak. Medio Picta alba is new in my garden this year and we have had rain so I'll check for standing water on the leaves.

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    1. You got rain? Real rain? Was it utterly wonderful? Sigh.

      Yes, that Medio Picta seems far more vulnerable to marks and marrs and blotches and scars...compare with parryi whose perfect silver skin is like Teflon (at least here).

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  10. Great post, Hoover! Two years ago I had sun damage after moving the agaves outdoors but not protecting them enough at first. What I hadn't realized until you mentioned it, was that some of the agaves recovered from being scorched, like A. scabra. I used to worry about too much spring rain, but after that lesson, I am also very careful about their first weeks of spring sun.

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    1. Good point from you and Gerhard about gradual introduction to stronger sunlight. I must add that.

      Scabra is a beauty! I love the sandpapery textured ones.

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  11. Thanks for this awesome lesson! I know understand what my flattened looking lovelies are missing - light! Oh well, maybe they will have to move out into the parking strip, but even that isn't all sunny. That 'Snow Glow' is gorgeous!

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    1. Plants will tell us what they want, we just have to listen. I'm still learning!

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  12. This is a good "to-keep-on-file" post, I had never thought of this. Especially seeing a client who's overwatered and his Agave bracteosa: all yellowish, grew too fast (I should have gotten concern then), and some now have spots on leaves.

    The differences in light and the effects on their forms are great to see.

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  13. I need to take these lessons out into the garden to check the condition of my own Agaves - I know some are suffering from sunburn but I'm less sure about their hydration. What are your thoughts about Agave pups? I'm always nervous about putting them in full sun while they're young.

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    1. My thought is the same as about all other plants here: best planted in late Autumn, so they can establish before summer hits.

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  14. Great post with terrific illustrations! I could provide examples of fungus, sunburn, hail damage, cold and related rot [weeps]... Damage limited to just a few species, interestingly enough. Most of my agaves seem pretty tough. The plants I lost to cold/rot are gone for good, but I'm giving the others a chance to grow out of the damage. We'll see.

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    1. Interesting--which ones failed for you? I had a little hail damage a few years ago on an attenuata, but it produces enough new leaves the damage was soon covered up.

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  15. Fabulous information...I just found this, a little late in the game. I have forwarded it to my mother, the proud mom of Oscar, the Agave parryi from Cistus. She's having Agave issues, hopefully this will help.

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    1. Thanks, I hoped it would be helpful. Best of luck to Oscar. He's a tough one--he can make it. :)

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  16. Okay so my problem with mine is that the leaves arent rolling up like a taco but the actual whole leaf is kinda humped over and twisting around the plan ..like the lower leaves are turning around the inner leaves like a tornado lo .

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    1. What species of Agave is it, do you know? What are the growing conditions it is getting? Do you have a photo of it on the internet anywhere? Sounds strange...

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  17. Thanks for this...observation then education, and remedial action. I have learnt to look a little harder at my plants and understand.

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    1. Happy you found it of interest. Thank you!

      I've learned if I just pay attention (sometimes for years) plants will tell me how they are feeling.

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