RIP, rotting 'Frosty Blue'—welcome, 'Desert Love'

In early March I wrote about a mysterious case of rot that had affected three of my agaves: Agave ovatifolia 'Frosty Blue', Agave 'Snow Glow', and Agave parrasana.

Agave parrasana is healing. The rot has stopped, and there's every reason to believe this specimen will pull through.

Agave 'Snow Glow' succumbed within a week of my original post and is nothing but a memory now.

Agave ovatifolia 'Frosty Blue' was one of my favorites and I was determined to put up a fight. I sprayed it multiple times with a fungicide (Daconil), keeping my fingers crossed that would do the trick. However, 'Frosty Blue' simply couldn't be saved; the rot had progressed too far. To this day, I don't know what had caused this outbreak.

This is what the area looked like on April 20, 2018:

These close-ups show how deep the rot had gone:

When I pulled on the leaves with the most rot, they came right out—as did the center:

In fact, every single leaf pulled out as easily as a hot knife slices through butter. 

After I had taken off all the leaves, a few minutes of digging with a spade was all it took to remove the roots. The result was a green waste bin full of foul-smelling plant matter and an empty spot where 'Frosty Blue' had been:

I drenched the soil several times: first with Daconil (chlorothalonil) and then with a product called Serenade which, according to its manufacturer, "is made from a unique, patented strain (QST 713) of Bacillus subtilis. Bacillus subtilis strain QST 713 penetrates and destroys the disease pathogen, but does not harm beneficial insects or wildlife when used according to label directions."

Whether this approach was successful remains to be seen, but I'm hopeful. 

A week after treating the soil, I replanted the area. This is what it looks like now:

These are the new plants I chose:
 Agave 'Desert Love', a naturally occurring hybrid between Agave ovatifolia and Agave parrasana (or possibly a threesome also involving Agave asperrima) discovered at Plant Delights Nursery   [MORE INFO]
 Dudleya farinosa   [MORE INFO]
 Banksia media (prostrate form)   [MORE INFO]
 Verbascum bombyciferum 'Arctic Summer'   [MORE INFO]
 ×Mangave 'Rio Verde'   [MORE INFO]
 Aloe ortholopha   [MORE INFO]
 Scabiosa 'Vivid Imagination'   [MORE INFO]

Agave 'Desert Love' is special and I do want it to thrive here. It does have that ovatifolia look, both in terms of leaf shape and color, but the parrasana genes should result in a smaller plant overall than straight ovatifolia.

Dudleya farinosa was on hand and needed a home so I planted it below Agave 'Desert Love'. I have a mixed track record with dudleyas so I give it a 50:50 chance of long-term survival.

My Banksia media is the prostrate form and it looks like it'll only be a foot, or maybe two, in height. It can spread out all it wants under and next to the Bearss lime tree. If its branches encroach on any of the succulents, I'll simply prune them.

Verbascum bombyciferum is a biennial; it will flower either this year or next and then be gone.

×Mangave 'Rio Verde' adds contrasting leaf texture and color and will end up in the 2-3 ft. range.

I bought Aloe ortholopha on my trip to San Diego a month ago. I'm hoping that given a bit more shade than it had at Evergreen Nursery the new leaves will be more blue. This is the look I'm after. The photo also shows its unique horizontal flowers; as far as I know, only Aloe ortholopha and Aloe marlothii have flowers that grow this way.

Scabiosa 'Vivid Imagination' is a pincushion flower with variegated leaves that may or may not do well in this spot. Either way is fine with me.

In case you were wondering, the cycad in the photos is Dioon edule (Palma Sola form). There's another one behind the 'Desert Museum' palo verde; you can't see it in these images.

So there you have it, another bed redone even though it hadn't been part of the master plan for 2018.

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  1. Very sorry about 'Frosty Blue,' but it looks like you've made the best of the situation. It's so frustrating when a favorite plant dies under mysterious circumstances.... What are the purple flowers in background behind it in the first few pictures? Penstemons?

    1. Mysterious, yes. But sometimes that's what happens. We don't have control over (or understand) everything :-).

      The purple flower is rock purslane, a succulent from Chile. It used to be Calandrinia spectabilis, now it's Cistanthe grandiflora.

  2. It's odd that 3 plants - and only 3 - were so severely and apparently suddenly afflicted. The newbies look great and I hope they enjoy good health in their new location.

    1. Very weird indeed. It goes to show that different species (even within one genus) are affected differently. Same goes for bugs. I've had a bunch of agaves side by side, and only Agave parryi var. truncata got mealybugs, the others didn't.

  3. My Yucca linearfolia did the same sort of thing--just mysteriously rotted. I still don't know why. Your replacements for 'Frosty' look really good. Maybe it wasn't planned, but it looks planned.

    Kay has that Dioon. I think she planted hers around 1972. It's 10' wide.

    1. I'm hoping my dioons will get big someday. Of course they'll be moved then--or rather BEFORE they get to that size.

  4. Curious why it rotted and it's a shame it succumbed but hopefully your area prep has done the trick and rot won't happen to the new plantings (which is a great selection!). Looking forward watching how they develop!

    1. I have another 'Frosty Blue' that I picked up last year. I'll grow it in a pot for now. You know, insurance policy!

  5. So interesting that those three plants rotted for no apparent reason. Your replacements look marvelous!

    1. This was just a reminder that nature does what it wants, not what I want :-).

  6. Gorgeous replanting, even if it was for mysterious reasons. I got that Desert Love also, but mine's still in a container. It will be interesting to see how big it gets!

  7. I'm so sorry about your losses Gerhard! What a heartbreaker! I've had inexplicable rot develop in potted agaves for no reason that I can determine and it is very frustrating. Sometimes you can save them by removing the rotting leaves, cleaning the plant and repotting in new soil, sometimes not. When they are in the ground and as large as Frosty though, it's really an impossible job.
    Best wishes on your replacements! We'll be looking forward to seeing them next year!

  8. I think I need/want one of those Aloe ortholopha. The inflorescence reminds me of Xeronema callistemon from New Zealand.

  9. My three year old A. bovicornuta did the same thing last fall. Center rot and mushy roots. I suspect I overwatered it but who knows.

  10. Your agaves were affected by the Agave Snout Weevil. It has destroyed several of my mature agaves.


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