Eyeball-worthy nuggets from around the web—2019 holiday edition

2019 has been a very busy year workwise. Long hours chained to my desk have meant little time for staying current on my favorite blogs, let alone scratching anything but the merest surface of the bottomless sea of information available online.

Fortunately, work slows down between Christmas and New Year's, allowing me to catch up on my reading. And since I love sharing, here are some particularly fascinating tidbits I've come across.

Greenovia dodrantalis
© rare_succulent on Instagram
Unusual succulents are one of the 5 hot houseplant trends for 2020

According to Yahoo Lifestyle, “unusual succulents” are #2 of the “5 Houseplant Trends That Will Be Hot in 2020.” As examples, they give “jumping dolphins” and “rose buds.” If you're like me and have no idea what these made-up names refer to, “jumping dolphins” are Senecio peregrinus and “rose buds” are Greenovia dodrantalis.

Greenovias, or mountain roses, are aeonium relatives from the Canary Islands. Looking at some photos online, I can see how they would appeal to plant lovers who like their succulents soft and unarmed. House Beautiful even had an article about the mountain rose in June: “Because it’s a succulent, you can keep it indoors with very little fuss.” (No comment on that.) If you want your own greenovia, Etsy sells plenty of them.

“Jumping dolphins” (Senecio peregrinus), also sold as “string of dolphins,” are companions to “string of pearls” (Senecio rowleyanus), “string of beads” (Senecio herreianus), and “string of bananas” (Senecio radicans). In habitat, these closely related succulents from South Africa creep along the ground and form dense mats. In captivity, they look great cascading from a pot. If you want your own string of dolphins, Mountain Crest Gardens sells them.

Senecio peregrinus
© Mountain Crest Gardens
Available for order
10 plant trends to watch out for in 2020
Succulents also fare prominently in another list of 2020 plant trends, this one published on the Nursery Management website. “People are discovering the immense variety that is the world of succulents,” an expert from the University of Florida is quoted as saying. “Their interesting shapes and growth habits seem to offer a form of living art.”

To us, this may not seem surprising, let alone newsworthy, but bear in the mind that what nurseries carry is largely driven by consumer demand. If consumer tastes in succulents become more sophisticated, we're going to see more unusual or uncommon varieties in mainstream retail channels (possibly including greenovias!). That benefits all of us.

Even more intriguing is trend #4, “re-wilding.” This means taking “steps to have less control in the landscape. This can include encouraging beneficial insects, reducing herbicide and pesticide use, pruning less and planting more native plants.”

I'm totally on board with having less control. Not only does it involve less work, it also allows us to experience unexpected discoveries and surprises. I realize that giving up a certain amount of control can cause anxiety, but leave yourself open to the possibility that the rewards just may outweigh your discomfort.

© Intelligent Living
Planting trees in square holes makes them grow stronger and faster
That's what a December 21, 2019 article on the web site Intelligent Living claims. Apparently, when planting a tree in a round hole, it will develop a circular root system, much like it would in a container. Ultimately, this creates a “girdle that chokes the plant.”

In contrast, your tree has a much better chance of thriving in a square hole because when the roots meet up with a 90° angle, they spread beyond the planting hole and penetrate the surrounding soil. These are the findings from systematic planting trials.

Whether true or not, it doesn't take much more effort, if any, to dig a square hole so that's what I'll do from now on.

© Florida Fruit Geek
Cold-hardy avocados
I'm not sure how many of you lose sleep anguishing over whether to plant an avocado tree in a borderline inhospitable climate, but here is a handy guide to cold-hardy varieties. Surprisingly, some of them can handle temperatures as low as 15°F!

According to this excellent article by Florida Fruit Geek (Craig Hepworth), there are three subspecies of avocados—Guatemalan, West Indies, and Mexican. Only the first two are grown commercially, but they're frost-sensitive.

The frost-tolerant varieties are from the Mexican subspecies. They aren't grown commercially to any great extent because their skin is so thin that transportation would be difficult and hence costly (apparently you can mash them up skin and all). Because of their high oil content, they have a rich flavor that apparently puts the commercial varieties to shame.

Most Mexican varieties can handle cold snaps to 18°F, some even 15°F with little damage.

In addition, there are hybrids between the Mexican and Guatemalan or West Indies subspecies. They have less cold tolerance but thicker skin, making it easier to transport and store them without damage.

I once bought an avocado tree (I can't remember which variety) and it survived in its #5 nursery pot for several years. I never did get around to planting it, mainly because our backyard is small and I didn't want to dedicate precious real estate to a tree that is really quite ugly. However, if I ever were in the market for an avocado tree again, I'd try a Mexican variety for their flavor.

© Tom Cowey, as seen on Bored Panda
Crown shyness, or why trees don't like to touch
I was stunned when I first saw a picture of this phenomenon. To appreciate this marvel of nature in all its glory, look at these photos on Bored Panda.

Why are these trees taking great pains to avoid touching their neighbors? Nobody knows for sure but there are several hypotheses for what botanists call “crown shyness,” “canopy shyness,” or “intercrown spacing.”

Some experts postulate it's to protect against mechanical damage that would be caused by rubbing against neighboring trees; others think it's to prevent the spread of insects from tree to tree. To me, the hypothesis that makes most sense is that trees are trying to maximize the amount of light that reaches the leaves on lower branches. Maybe it's a combination of things.

Crown shyness is seen in a variety of trees, ranging from tropical and subtropical species to some European oaks and pines. This drone footage from Mexico is a jaw-dropping illustration this phenomenon:

Forest Therapy - Do Nothing for 2 mins... from Dimitar Karanikolov on Vimeo.

© Guillermo Rivera
Plant expeditions
I just received the latest newsletter from Guillermo Rivera Plant Expeditions. As always, it's full of drool-worthy destinations: Baja California, Namibia, Ecuador, South Africa/Namaqualand, Argentina, Chile.

Guille Rivera has been leading plant-focused trips to the Americas and Africa for decades. Several friends of mine have traveled with him, and they loved every minute. I've never been able to go on one of these trips, but it's wonderful to dream, especially when it's cold outside.

On that note: Happy Holidays to you and yours!


  1. This was a fun post! I'm glad you've managed some time to breathe and enjoy the holidays. Merry Christmas Gerhard!

  2. Dear Gerhard
    I write from sunny Cape Town, South Africa. Thank you so much for your blogs, which I am sure at times must involve quite a lot of work. I really enjoy reading them, and have learnt a great deal from them. My own garden was fashioned as a typically English garden, with all the plants that go with that. Some years ago we experienced the beginning of climate change, with no rain and very hot temperatures during our winter months, when normally it would rain and temperatures would drop to more livable levels. It came with the realisation that purchasing water every ten days [5,000 litres a time] would not be financially sustainable, and thus started the beginning of the change to the garden. With it came such a fascinating journey [long not finished...] for my gardener and I along the road with aloes, succulents, grasses, tough perennials [salvias come to mind, plectranthus, geraniums] and bulbs. And the occasional agaves. It has been at times an expensive exercise changing the garden, and trying to understand the fact that much less water is required - I also had to learn about how aloes require less rather than more fussing. Your blog has at all times been so inspirational and educational along the journey, and I am most grateful to you for guiding me. I do hope you will be able to visit our country at some stage - it is a beautiful place, and the flora will leave you as excited as some of that you have written about. James Hitchmough, on instagramme writes a great deal about some of South Africa's plants, and I hope it will be enough to encourage you to book a trip soon. I look forward to reading your blog in 2020. Kind regards Rene Johnson

  3. The Crown shyness phenomenon is surreal, but in my garden the birch is hugging the cedar totally unabashed. The idea of square hole planting is intriguing; I'm definitely giving it a try with my next tree. Merry Christmas and Happy New Year!

  4. Interesting information re: square holes for trees. Maybe 2020 will be your lucky year to indulge in a 'once-in-a-life time' trip. Any of those trips looks amazing. Best of the holiday season to you. Enjoy Arizona.

  5. Ha ! The square hole thing has been making the rounds on the internet--even a modest flame war on Garden Web,and some drama on the Garden Professors FB page. My biggest takeaway was pondering how many 4" square nursery pots have been root bound over my decades of gardening. Love the crown shyness stuff.


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