Saturday, February 5, 2011

Echeverias—flowers of leaves

Echeverias are rosette-forming succulents native to Mexico and Central America. There are dozens of species, and literally hundreds of named cultivars bred for specific characteristics such as color, size or leaf shape. Considering the sheer variety, it’s easy to see why echeverias have become the darlings of the design world, featuring prominently in everything from mixed succulent bowls to living wreaths and vertical gardens.

I’m not a designer and don’t pay too much attention to what the Martha Stewarts of the garden world happen to dream up in a given season, but I do think that echeverias are among the most beautiful of succulents. Their rosettes often remind me of flowers—flowers of leaves that never stop blooming.

In their natural habitat, echeverias grow at higher elevations marked by low humidity and moderate temperatures. In areas where hot summer temperatures routinely exceed 90°F, they prefer semi-shade. However, too much shade causes their rosettes to stretch and lose their symmetry (a phenomenon called “etiolation”). In addition, some of the more colorful echeveria varieties assume a sickly greenish cast if they don’t receive enough sun.

Like all succulents, echeverias need well-draining soil. If your native soil is too heavy, you can amend it with pumice, lava rock, decomposed granite, pea gravel or similar materials. The best solution would be to plant your echeverias in a raised bed or on a mound of light-textured soil. This will prevent root rot, especially during a wet winter.

Echeverias have some frost tolerance, down to the 25°F range, allowing them to be planted in the ground in zones 9b and up. If your winters are colder than that, you’re better off relegating them to containers that can be protected from the cold or moved inside.

Most echeverias form offsets and can create extensive colonies over time. In my book, this is one of their most desirable traits. Simply pluck one of the offsets, stick it in soil, and you’ve got a new plant—and the beginnings of yet another colony. (Some authors recommend leaving the offset in a shady location for a week or two, or until new roots begin to form. I’m too impatient and put them in soil right away; I’ve never lost an offset that way.)

Here are some of the echeverias I photographed the other day at Ruth Bancroft Garden in Walnut Creek. Some of these species are common, like Echeveria elegans, others are quite rare, like Echeveria expatriata.

Echeveria expatriata, rare
Echeveria agavoides, a fairly common species, often with red-tinged leaf margins
Echeveria pulchella, uncommon
Echeveria setosa, one of the fuzziest echeverias
Closeup of Echeveria setosa. I love the fuzz—it reminds me of a tarantula
Echeveria elegans in the foreground, with aeoniums planted behind it
Echeveria elegans, one of the most commonly found species
Echeveria ‘Gilva’, an old hybrid of unknown origin but assumed to be a cross between Echeveria agavoides and Echeveria elegans
Echeveria ‘Hummel #1’. This hybrid is only found at the Ruth Bancroft Garden. It was received from plant breeder Ed Hummel in the 1960s. See here for more info if you’re interested.
Echeveria ‘Hummel #1’ and an unidentified groundcover aeonium
Echeveria ‘Violet Queen’, an Echeveria elegans hybrid
Echeveria ‘Powder Blue’. Looks anything but powder blue to me, but maybe the coloring becomes more pink in full sun?
Beautiful hybrid for sure.
Echeveria ‘Lace’. A very large hybrid with curly leaf margins. Its general appearance and size remind me of ornamental kale.
Closeup of Echeveria ‘Lace’. This one, like all other echeverias with ruffled edges, is most likely a hybrid of Echeveria gibbiflora.
Echeveria ‘Firelight’, yet another frilly gibbiflora hybrid. I can appreciate it for its unique look, but personally I prefer non-ruffled varieties.

SIDE NOTE: Echeverias are sometimes referred to as “hens-and-chicks”—an unfortunate choice since “hens-and-chicks” is the common name for sempervivums (also known as “houseleeks” or “liveforever”). While some of the smaller echeverias do resemble sempervivums, there are significant differences. Sempervivums are Old World plants native to the mountains of central and southern Europe. They are very cold hardy; some sources claim down to -30°F as long as sharp drainage is provided (I don’t know why that would matter since at -30°F the ground would be frozen solid anyway.)

In turn, sempervivums don’t do all that well in hot climates. I have a few sempervivums that have hung around for a number of years. While they look great—and grow very fast—in the spring and early summer, they do get ratty by July, with individual leaves or entire rosettes turning brown and the colony assuming an unkempt appearance. I imagine that in even hotter climates, like the Southwest, it would be virtually impossible to grow sempervivums well.

Friday, February 4, 2011

Winter protection for succulents at Ruth Bancroft Garden

Yesterday I had a meeting in the East Bay, so I decided to swing by the Ruth Bancroft Garden in Walnut Creek to see the garden in the winter. I’d last been there in July when everything was baking in the summer heat.

In the winter, things are decidedly different. For one, I was the only visitor. The only other people there were a few volunteers doing chores like weeding, removing dead plant material, etc. In addition, many plants were covered against the frost as much as against excess water. As you can see in the photos below, this ranged from simple boxes for individual specimens to covering an entire area, in essence turning into into a temporary greenhouse.

When Ruth Bancroft created the garden more than 50 years ago, hundreds of tons of crushed rock were brought in from Mount Diablo just a few miles to the southeast to amend the heavy local soil and to improve drainage. Over the years, additional quantities of rock have been added. Many beds are mounded to varying degrees in order to prevent plants from becoming water-logged during our wet winters. Most types of succulents make do with little water in the summer; the real enemy is too much moisture in the winter.

Looking south from the entrance
Group of golden barrel cactus (Echinocactus grusonii) near the entrance
As you can see, they are simply covered with semi-transparent plastic and tied at the bottom to keep the plastic in place.
I was a bit surprised seeing the plastic so tightly wrapped around the golden barrels. I would have thought that the plastic touching the plants during a frosty night would cause damage, but that doesn’t seem to be a concern with cacti—and neither, apparently, is the lack of breathability of the plastic. The overriding concern is to protect these cacti from excess water; frost protection isn’t an issue here since golden barrels are hardy into the high teens.
A more open shelter. Underneath are coral aloes (Aloe striata), hardy to 24°F or so. As winter growers, they are used to receiving moisture in the winter. There must be a good reason for covering them, but I wasn’t able to figure it out. The three coral aloes in our garden are completely exposed in the winter, and they’re just fine. In fact, their leaves are engorged right now from all the extra water they’ve received.
A frost protection box for a Sunburst aeonium. Aeoniums are touchy about frost; they sustain damage at 28°F and go to mush not far below that.
In the summer this is a shade area to shelter more tender plants from the hot afternoon sun. In the winter, it is completely enclosed to provide frost protection.
Essentially, this area becomes a temporary greenhouse. Some plants in here would do just fine outside, for example the large variegated century plant (Agave americana 'Marginata').
The sun casts beautiful shadows on the walls of the structure.
Agave and aeonium planting inside the covered area. The beautiful clump in the back is Agave lophantha. However, the smaller agave in the middle is the real star here. It is a perfect specimen of the rare variegated foxtail agave (Agave attenuata 'Variegata'). It’s only the second one I’ve ever seen. I wish I could have gotten a little closer but I didn’t want to leave the path and trample through the planting bed.

Coming tomorrow, 2/5/11: Lots of echeverias. I took photos of at least a dozen different species/hybrids, and I’m sure there were more that I missed. Echeverias are very popular, judging from the constant stream of new cultivars coming on the market, and it’s easy to see why.

Thursday, February 3, 2011

When a gallon ain’t a gallon

Like everybody, I have a list of pet peeves. Mine includes daylight savings time, tipping, the inability of our newspaper carrier to deliver a dry paper, and the size of nursery containers.

If you’ve ever measured the volume of a “1 gallon” nursery pot, you know that it’s not 1 gallon (3.8 liters). Not even close. In fact, depending on the manufacturer of the container, it might be as little as ¾ gallon (2.85 liters). That’s ¼ less than—well, what? Certainly not less than labeled because nursery containers typically do have the actual volume printed on the bottom. It’s simply less than we expect, based on the tradition of calling a #1 container a “1 gallon container”.

I had been wondering for a long time where this discrepancy comes from. Just the other day I happened to come across this discussion on GardenWeb. Never mind that it’s from 2005, the information is still good. A poster calling himself “calistoga” contributed what I consider to be as good an explanation as any:

As I understand it, we got into this "gallon" reference when the nurseries boomed at the end of WW2. Our government had contracted with canners to pack millions of one gallon cans of foodstuffs to feed the armed services. At wars end there was a very large surplus of one gallon cans available cheap that were grabbed up by the nursery growers. Since they WERE one gallon cans that was what they called them. When the surplus was gone and new cans were ordered a tapered can that would stack was a lot more practical. The advent of plastic made a tapered can much easier (and cheaper) to produce. The name "gallon" persisted even when the container would no longer hold a gallon of anything. Some time ago the weights and measurement people started looking into "false size claims". Since then the industry has been trying to eliminate any reference to "gallons". Hopefully in the near future the industry will decide on names for sizes that can be standardized and make sense to us all.

This makes total sense to me. So many of our traditions go back to some war or other.

Further research revealed that a “#1 pot measures 6" wide by 7" deep and has a capacity of 183 cubic inches (6). Once the plant has been put into the pot, and some space has been left at the top for water, ten #1 pots can be filled with a cubic foot of soil. With 27 cubic feet of soil in 1 cubic yard, a nursery can pot up 270 #1 pots with a cubic yard of either soil or container mix. If #1's are placed pot-to-pot, in rows 12 pots wide, with 2.5 foot alleys between, approximately 2,700 #1's can be set out on 1,000 sq.ft. of ground”.

If this didn’t make your head spin, you’re made of a stronger fiber than me!

More practical, at least for this spatially challenged brain, is this list of nursery container sizes from Moonshine Designs Nursery:

  • A "gallon" pot is also known as a "#1 trade size". It does not actually hold a gallon of liquid or dry measure. Actual capacity is 0.78 to 0.98 gallon.

  • 1 gallon "true gallon": 1.0 gallon 7" x 6".

  • 2 gallon: 1.9 gallon 10" x 7 3/4". 

  • 3 Gallon: 2.9 gallon 11" x 9 1/2". 

  • 4 gallon: 3.9 gallon  12 x 11 1/4". 

  • 5 gallon: 4.7 gallon  13 3/4 x 10". 

  • 7 Gallon: 7.5 gallon  15" x 12 1/2". 

  • 10 gallon: 11.1 gallon  18-1/2" x 12". 

  • 15 Gallon: 14.7 gallon  18-1/2" x 17"

Looking at this list, it becomes clear that the “gallon” pot is really the only one that has issues. Maybe we should all be buying plants in 2-gallon sizes and up? Or maybe we should simply stick to tradition, call a ¾ gallon container a “one gallon”, and pretend that I never wrote this post?

Readers in other countries, how are nursery containers measured where you live?

Wednesday, February 2, 2011

Moving a large Eve’s Needle cactus

I rarely repost entries from other blogs—actually I don’t think I’ve ever done it before—but I found this one so interesting that I requested and obtained permission to post it here (thank you, Peter).

Have you ever wondered how commercial nurseries move large cactus specimens? Check out these photos from Cactus Jungle in Berkeley, CA. The task is to move an 8 ft. Eve’s Needle cactus (Opuntia subulata or Austrocylindropuntia subulata) from the nursery to a customer’s house 40 miles away.

Opuntia subulata being mummified for the trip. Ian, Keith and Hap of Cactus Jungle (and Brian not in photo) are hard at work with newspaper, cardboard and plastic at the nursery in Berkeley.

Securing the plant in the truck.

On the deck at the customer’s house. That must have been hard to get it up there. It took four people to lift the cactus up the stairs.

And the final resting place of this giant cactus, with pot feet, in Pleasanton, CA, east of Berkeley.

Cactus Jungle is the San Francisco Bay Area’s premier cactus and succulent nursery. Located in Berkeley just a few blocks off Interstate 80, Cactus Jungle offers a large variety of plants, including many not seen in other commercial nurseries in Northern California. The owners, Hap Hollibaugh and Peter Lipson, write a very entertaining blog that I follow regularly.

Tuesday, February 1, 2011

New plants that make me drool

It’s the time of year when mail-order catalogs and e-mail offers come flooding in, tempting us with the latest plant introductions. While fairly immune to flowering plants, I’m a total pushover when it comes to ornamental grasses, succulents and anything with striking foliage.
Here are some recent drool-worthy discoveries:

Blonde Ambition blue grama grass (Bouteloua gracilis 'Blonde Ambition'). A Plant Select winner for 2011, this extremely striking and very cold hardy grass was discovered and introduced by High Country Gardens, and as far as I can tell can is only available from them at the moment. I saw the regular Bouteloua gracilis in a planting in downtown Davis last year and fell in love with it. This cultivar is almost twice as tall and hence even more impressive. High on my list of must-have plants.
From Proven Winners comes a new pennisetum called Vertigo (Pennisetum purpureum ‘Vertigo’). This fountain-grass relative from the grasslands of Africa is purple and big—up to 4 ft. I think it would make a great backdrop for smaller grasses with thinner leaves and delicate flower pannicles, such as dwarf fountain grass (Pennisetum alopecuroides 'Little Bunny'), or even for flowering perennials like shorter echinacea hybrids.
Variegated northern sea oats (Chasmanthium latifolium ‘River Mist‘) from ItSaul Plants. Take a look at this closeup of the leaves. Looks just like a variegated bamboo (Pleioblastus fortunei comes to mind). I love the non-variegated version of northern sea oats, and this one looks to be even more stunning. Available at Plant Delights, High Country Garden, and many other retailers.
Agave xylonacantha 'Frostbite', available at Yucca Do and Plant Delights. I’ve never seen an agave this intimidating—the leaf margins look like veritable saw blades. Yet there’s something undeniably elegant about the overall look. This plant has cojones and tells you in no uncertain terms to keep your hands to yourself. I love it.
Arkansas blue star (Amsonia hubrichtii), 2011 Perennial Plant of the Year. This often overlooked Arkansas and Oklahoma native has finely textured foliage that is green all summer and turns golden-yellow in fall. In spring, masses of light blue flowers add additional interest. Would look great in combination with large-leafed tropicals. Available at many nurseries, including Blue Stone Perennials.
Plant Delights never disappoints when it comes to exciting new introductions. Even though I’m at the tail end of my banana obsession (the realities of our climate have finally sunk in), this Bengal Tiger banana has got me drooling. Luckily the photo on the Plant Delights web site is pretty awful, otherwise I really couldn’t resist.
I don’t have room for this and I don’t live in the right zone (zone 6-7) but, wow, this is a stunning variegated holly cultivar called Casanova (Ilex meserveae 'Casanova') available from Heronswood. The pink tinge appears in the winter. What a great way to add year-round zing to your woodland garden.
I love sea holly and have a hard time understanding why it’s almost impossible to find in local nurseries. Maybe because it’s prickly, and most nursery customers prefer soft and cuddly? For me, the drama of a sea holly in bloom is hard to beat. This cultivar from Blooms of Bressingham, available at High Country Gardens, is called Big Blue (Eryngium x zabellii 'Big Blue') and looks to be even bluer than the other cultivars already on the market. My experience with sea hollies is that they need a couple of years to really get going since they first need to develop their long taproot. After that they are very drought-tolerant.
Be sure to read this interesting article on Big Blue sea holly.
OK, I can’t conclude this post without at least one annual. This new sunflower hybrid from Burpee, called Coconut Ice, claims to be the first truly white sunflower. It starts out creamy vanilla and then fades to white. I don’t know why the world needs a white sunflower, but if I find seed locally, I will definitely give this one a try. It would look awesome intermixed with yellow and brown sunflowers.

Monday, January 31, 2011


You may not recognize the word, but you’ve seen it in things like door mats, twine or brushes. Coir—pronounced COY-er or core, depending on who you ask—is the coarse fiber found between the outer husk of a coconut and the edible “nut” inside. It is sometimes called “coco peat” or “palm peat”, presumably because its color and horticultural usage is similar to sphagnum peat moss.

The coconut palm (Cocos nucifera) has been in cultivation for at least 4,000 years, not just for food but just as importantly for fibers, fuel and building material. Not surprisingly, coir has played an important role wherever coconut palms are grown, mostly as the raw material for rope and twine. Click here to read an interesting article on the history and making of coir.

The use of coir for horticultural purposes is relatively new. Traditionally, peat (sphagnum peat moss) has been used to aerate and lighten heavy soils and to improve the water retention of sandy soils. In fact, many if not most commercial potting soil mixes on the market today contain at least some peat. The problem with peat is that it is not a renewable resource and is being harvested at non-sustainable rates.

Coir is being touted as a viable alternative since it is a by-product of coconut production and completely renewable. It is much easier to wet than peat (if you’ve tried to wet dry peat, you know how difficult that can be), holds water just as well if not better, decomposes more slowly and doesn’t get compressed like peat does. In addition, the pH of coir is more neutral than peat so it doesn’t change the pH level of the medium to which you add it.

I became aware of coir when researching potting soil mixes for succulents. Many commercial cactus mixes are surprisingly high in peat. Once the soil is dry, it is very hard to rewet it; this results in a lot of wasted water and, on my part, in a lot of frustration. I decided to give up completely on commercial  cactus mixes and make my own, based on the experience and recommendations of other succulent growers.

Many growers use coir in varying proportions in their soil mixes. Since coir has a stable, open structure that allows plenty of air to get to the roots, it is an ideal amendment to create a loose and well draining soil mix. Combined with at least 50% pumice, perlite, calcinated clay or the like, coir with its superior water-holding capability ensures that the mix doesn’t dry out too quickly, yet at the same time doesn’t subject the roots to an excess of much moisture.

After digesting the information I found online and in books, this is the soil mix recipe I’ve settled on: 50% pumice (in the form of Dry Stall, a horse bedding product sold in feed stores), 25% coir and 25% commercial potting soil. I will give this a try for all potted succulents, starting—well, as soon as my coir is ready to use.

Coir block

Coir typically comes in compressed bricks that are surprisingly heavy. According to the instructions I received for the bricks I bought, “simply place the brick in a bucket of water and walk away”. Well, I did just that, 24 hours ago, and half the brick is still, well, a brick. But what has come off—in no small measure due to my whacking, prodding and scratching with a cultivating mattock—is beautifully fluffy and fiber-y.

Coir after rehydration

Another day or three, and my coir should be ready to go. I can’t wait to make up my first batch of succulent potting mix. My golden barrel cactus would really like a new home!

High-fiber diet for the soil—looks good enough to eat!

Sunday, January 30, 2011

Succulent sale at Silverado through 2/5/11

This post is of interest mainly to Sacramento area gardeners. Silverado Silverado Building Materials & Nursery in Rancho Cordova is having a big sale on all kinds of things, including pottery, fountains, ornamental and fruit trees, roses, and succulents. Succulents in 1 gallon and larger containers are 40% off, 4" plants are $2, and 2" plants are $1. This sale runs through 2/5/11.

I went this morning and ended up with a bunch of stuff. Some succulents looked pretty sad (that might be the reason for the sale), but others were in decent shape. However, even the sad-looking ones should make a recovery once warmed weather sets in. Succulents are tough.

There were just a few agaves and aloes—and the requisite golden barrel cactus—but almost everything else was echeverias, sedums, crassulas and other members of the Crassulaceae family. A nice selection overall, but many plants either had no ID tags (especially the small 2" pots) or the wrong tags. Most people don’t really care what they get as long as it’s attractive to them, but I’m a stickler for correct labeling.

This kind of sale is worth going to if you’re designing mixed succulent bowls and need lots of plants, or if you are looking for smaller plants than are available in most nurseries. $1 for a 2" plant is a good price, especially considering how fast these grow. Potted now and watered and fertilized throughout the growing season, they’ll be a nice size by fall.

Here is my haul of the day:

Senecio vitalis, or narrow-leaf chalksticks, hardy to 25°F. More upright (and less blue) than the blue chalk fingers (Senecio mandraliscae) we have growing in our succulent beds. It’s a bit unkempt right now but once I’ve removed all the dead leaves, it will look great.


Sedum pachyphyllum, or many fingers, hardy to 15°F. Definitely one of the “fleshiest” sedums I’ve seen. This plant is in a one-gallon container, and it was surprisingly (top) heavy—there is lots of water in these leaves!

Closeup of Sedum pachyphyllum, If this plant hadn’t been tagged, I would never have guess that this is a sedum.

Graptopetalum paraguayense or ghost plant, supposedly hardy to 5°F. Quite common in 3" or 4” containers, but this is the first time I’ve seen it as a gallon-sized plant. I could cut off each rosette and root it, and I’d have over a dozen individual plants! In addition, you can root each leaf individually. Truly one of the easiest succulents in terms of propagation.

Labeled as Pachyphytum opalina, or opal moonstone. However, such a species doesn’t seem to exist. In all likelihood, this is x Graptoveria ‘Opalina’, a graptopetalum x echeveria hybrid.
Labeled as Graptopetalum amethystinum, or lavender pebbles. Not 100% sure about the ID because the color is too pink, but that might be because of the winter cold and/or growing conditions. Definitely very plump leaves that make the plant surprisingly heavy. A beautiful plant, and my favorite find of the day.

Now I need to figure out what to do with these plants and the ones I got from IKEA a couple of weeks ago

Saturday, January 29, 2011

Wildflower seed paper

Today I received a promotional mailing from Google, presumably because this blog is hosted by Google’s Blogger service. I almost threw it in the recycling bin but then I realized that the paper the offer is printed on is not just regular paper. The mailing says:

This card was printed on 100% recycled paper embedded with wildflower seeds. Plant it in a sunny spot with a thin layer of soil, add water, and watch it grow—while you watch your business grow with AdWords.


Google mailing on wildflower seed paper; the dark specks are the embedded seeds

Usually I’m as jaded as they come as far as advertising is concerned, but I must admit that as a gardener I was impressed by this particular twist. A web search—on, no less!—revealed that wildflower seed paper isn’t all that uncommon. There are quite a few vendors that sell all kinds of paper products embedded with seeds. Quite often the paper is recycled, which makes for a perfect green package.

Among the products I saw online, this wrapping paper caught my eye:


I have a conflicted relationship with wrapping paper (too expensive, too glossy, too environmentally unfriendly), and I was delighted to see this. However, at $20.00 a roll, it’s outrageously expensive, so I’ll stick to my tried-and-true method of using the Sunday cartoons as wrapping paper.

As for my card from Google, it’ll go into one of our raised vegetable beds where I can keep a close eye on it. I’m dying to find out whether anything will grow.

If you’ve tried this kind of paper before, please leave a comment below. I’d love to hear what happened.

Friday, January 28, 2011

First bamboo shoot of the year

It’s late January, and some of our bamboos will soon start to produce shoots. Typically, the earliest shooting species in our yard are Fargesia dracocephela ‘Rufa’ and Fargesia robusta, two clumping mountain bamboos from China. These two are no doubt busy developing shoots which will soon rise from the ground like an army of zombies. (Man, where did that muddled metaphor come from?)

Yellow Buddha Belly (Bambusa ventricosa ‘Kimmei’)

However, this year the first bamboo to shoot is yellow Buddha Belly (Bambusa ventricosa ‘Kimmei’), planted in a large pot on our back yard patio. This is especially surprising since it’s a subtropical clumping bamboo that typically shoots in the summer and fall, triggered in its native habitat by the onset of the monsoon season. Maybe it has to do with all the rain we had in late December? Whatever the cause, this early shoot is a vivid reminder that bamboo manages to surprise even people who think they know a thing or two about this remarkable grass family.

Buddha Belly shoot poking out of the ground

Yellow Buddha Belly, like its all-green sibling, is renowned for its swollen internodes—the sections between the nodes (rings) along its culms. These “bellies” typically appear when the plant is grown in a hot and exposed area and starved of water and nutrients. In containers it is easier to force the growing conditions needed to produce this swelling. However, as I learned from personal experience, it’s rather difficult to find the ideal balance between keeping the plant dry enough so bellies develop and withholding too much water, in which case the leaves dry up and fall off. It’s a good thing that bamboos are resilient and quickly replace dead leaves as soon as watering is resumed.

The most pronounced bellies on our specimen are on the original culms; the new culms show just a hint of bulging. I’m very curious to see if I can get our plant to reliably produce bellies as it matures.

“Bellies” on yellow Buddha Belly

Specimens that exhibit the belly effect are significantly shorter (a maximum of 12-15 ft, with 8 ft being typical). Planted in the ground and given regular water, however, Bambusa ventricosa is a large clumping timber bamboo that can reach 55 ft. In that case, its culms are straight, with no bulging.

I do admit that I was drawn to this bamboo species because of the swollen internodes. I will continue my quest to force bellies even though I do feel a bit like a torture master!

All-green buddha belly bamboo with swollen internodes at Mad Man Bamboo