Metasequoia glyptostroboides update, and future plans.

Back in April I wrote about germinating some Metasequoia, or Dawn Redwood, seeds. In all, five seedlings germinated. The tallest of these grew to about ten inches, while the smallest two are around six inches. I had planned on posting an update back in August, but actually working in the garden took precedence. But I did take a photo before moving the potted seedlings to a sheltered location outdoors.

Metasequoia glyptostroboides seedlings, August 2014.
Photo by Bill Jury.

As you can see from the photo above, even the smallest of the five seedlings was doing well. The pot in the upper right actually has two seedlings that I have yet to separate, but there's still room in the pot (I'll separate them in the spring). These spent the remaining days of August, September, and most of October - basically until our first hard freeze - in a lightly shaded location outside. In late October, on the evening of our first serious freeze, I pulled the seedlings into our insulated garage. A cold frame would be better, but the garage window works for the time being. At this time the largest seedling has dropped much of its foliage, the next two largest are somewhere in between, while the smallest two are still holding on to their needles. Otherwise, all five of the seedlings show healthy, dormant buds ready for the warmth of next spring.

Metasequoia on the San Jose University Campus.
Photo by John Pozniak.

The future? As I wrote back in April, this is a big tree, but I am working on preparing a spot for one toward the back of the garden. If all goes as planned (a big "if" when gardening in Colorado), I might eventually have the tallest tree in Milliken!

Kiwano Melons.

I'm always interested in trying new fruits, so for my birthday last month my wife got a Kiwano Melon for us to try. It looks like something from another world, so much so that Star Trek: Deep Space Nine used them in the episode "Time's Orphan" (repurposed as "Golana Melon"). Covered with several hard, horn-like spikes, the Kiwano Melon, known scientifically as Cucumis metuliferus, turns a radiant orange when ripe. This contrasts with its pale-lime flesh. Kiwano Melon, in the Cucurbitaceae family, is related to cucumbers and gherkins, and the flavor of its flesh typically includes "cucumber-like" as a descriptor. I say includes because, in addition to hints of cucumber, I also tasted green banana and citrus. Deborah and I enjoyed it, but Corran wasn't too sure about the texture (as one source writes, "the pulp resembles lime-green Jell-O"). Still, he ate it...but, aside from unsweetened lemon, Corran hasn't met a fruit he hasn't liked.

Fruit of Cucumis metuliferus, the Kiwano Melon.

Cucumis metuliferus is an annual vine native to Africa and is cultivated as a traditional African food. It, along with the Gemsbok Cucumber (Acanthosicyos naudinianus), is a significant - some say only - source of water during the Kalahari Desert's dry season. When eaten fresh, most people suck out the pulp and spit out the seeds, though the seeds themselves are also edible. I saved ten of the seeds and planted them in starter pots. After all, if Kiwano Melon will grow as a crop in New Zealand and California, Colorado should have plenty of heat and sun. And, since our growing season is long enough for other melon crops, there should be more than enough time for the Kiwano Melons to ripen. I wasn't even sure if the seeds would be viable, but they were.

Growing Cucumis metuliferus trellised as a vine is the recommended method, but you can let it grow along the ground. Given its desert origins, Kiwano Melon prefers infrequent watering; allow the soil to dry out between waterings. It grows fast, so I am going to have to design and install some trellises before too long. But it will be worth it!

If you're interested in growing a Kiwano Melon, and you can't find one in your local market, Baker Creek Heirloom Seeds sells packets of this and other unusual edibles and ornamentals.

The first sprouts of Ribes aureum and Shepherdia argentea.

A few days ago the first Shepherdia argentea, or Silver Buffaloberry, began germinating. This native fruit has the potential to grow to almost 20 feet in height with a spreading crown of equal size - much larger than its native cousin Shepherdia canadensis (Russet Buffaloberry). The fruit, a red fleshy drupe with a variable taste, was used historically by several Native American peoples as food, medicine, and dye. Many report that the fruit is bitter, but this is attributed to the presence of saponins; frost reportedly causes the sugar content to increase, improving the flavor. In any case, Silver Buffaloberry is drought-tolerant and, with pruning and shaping, can make a beautiful large shrub or small tree with silver-green leaves. Of course, like many native fruits, Shepherdia argentea is armed with impressive thorns. The fruit is mealy and considered edible, not necessarily delicious. However, its value from an ethnobotanical perspective (not to mention its drought-tolerance) makes the Silver Buffaloberry well worth the time and effort to grow it.

Shepherdia argentea. Photo taken at Chief Whitecap Park
in Saskatchewan, Canada by SriMesh.

This morning I also noticed the first of the Ribes aureum, or Golden Currant, sprouting. I hope to see more germinating in the next few days. This is another native fruit; the clove-scented yellow flowers are the source of its common name. Ribes aureum is considered one of the most delicious of the wild fruits adapted to our region. Unlike Shepherdia argentea, Ribes aureum is thornless. Though tolerant of moderate shade, it prefers moist soil in full sun. Typically three to six feet tall, the Golden Currant can grow even taller under optimal conditions. The berries, appearing on short racemes from the leaf axils (the base of the leaf at the stem), ripen from mid to late summer, turning a deep black or black-purple color. I am looking forward to establishing a small thicket of Golden Currant this year!

Ribes aureum. Photo by Stan Shebs.

Germinating Yucca elata and Yucca faxoniana.

Last year I sprouted several Yucca baccata (Banana Yucca) and Yucca elata (Soaptree Yucca), and while I grew out many Yucca baccata, I only managed to grow out a single Yucca elata. Despite our brutally frigid temperatures, this single Soaptree Yucca handled the Colorado winter seemingly with ease. This is encouraging - the tree yuccas fascinate me, which naturally means I plan on growing some more.

Today I began cold-stratifying eight Yucca elata seeds and eight Yucca faxoniana (Texas Tree Yucca) seeds. Yucca elata is probably the hardiest of the tree yuccas, but success with yuccas, agaves, and their kin is determined by many factors, and USDA hardiness zone is only one of these. Siting (soil structure, exposure, microclimate, etc.) seems to be as critical in determining success with members of the family Agavaceae, particularly when planting them in areas pushing the limits of their cold-tolerance. My Yucca elata is growing on an exposed bed of decomposed granite, granite chunks, pumice, and loam-amended clay (the native soil). Since our regionally native Yucca glauca (Soapweed or Great Plains Yucca, a short colony-forming species) thrives in our local soil, I'm not surprised that its relatives have done well either. Still, since many reputable sources cite Yucca elata as hardy to "about zone 6a", I am very pleased that our less-than-a-year-old seedling survived the winter. Yucca elata has a reliable branching habit, adding to its "tree" image.

Yucca elata blooming. Photo by Stan Shebs.

Yucca faxoniana - the Texas Tree Yucca - is the other tree yucca that I am attempting to propagate. This hardy tree yucca has one of the thickest, stoutest trunks (a foot in diameter) that supposedly forms a single stem reaching a mature height of up to 15 feet. I am following a similar protocol for cold-stratifying the seeds (about a month), since it seems that yuccas benefit from cold-stratification even if they are native to a milder clime. Some sources claim that Yucca faxoniana is hardy to USDA Zone 5, while others are far more conservative (USDA Zone 8), so I will just have to grow them out and see. My source claimed it was hardy to USDA Zone 5. As I wrote earlier, it seems that Yucca faxoniana is similar to Agave parryi in that differing populations of the same species can have quite different hardiness limits depending upon the conditions of their native environment. Perhaps my seeds come from a hardier population. We'll see. I plan on growing these near my Chilopsis linearis (Desert Willow) in a protected, sunny location that warms to daytime temperatures quickly in the winter.

Update 04-23-2014: I was able to read the section in Mary and Gary Irish's excellent book Agaves, Yuccas, and Related Plants on Yucca faxoniana and they indicate that it can tolerate severe cold - a relative term here in Colorado - down to approximately 0 degrees Fahrenheit. We frequently get a tad colder, but I still think siting will play a factor in its success or failure.

Yucca elata with Yucca baccata in the upper right.
Photo by Bill Jury.

I also managed to get a photo of my Yucca elata yesterday. It is putting on new growth and has very little winter damage. Not too bad for a year-old seedling.

Grass trees and ginkgo.

A few days ago I received a grafted year-old Ginkgo biloba 'Mayfield' from Kigi Nursery. This happened to coincide with one of Colorado's late-Spring cold spells, so I simply potted the little tree up. Besides, the ginkgo hasn't broken dormancy yet, so forcing it to wait for warmer weather shouldn't really be an issue. For those unfamiliar with this particular cultivar of ginkgo, 'Mayfield' is an upright columnar form, and it is probably the narrowest in cultivation. Introduced from Ohio in the 1940's, Ginkgo biloba 'Mayfield' is not as well known as 'Princeton Sentry', but it is the perfect specimen tree for our small, commensurately narrow yard.

Ginkgo, of course, is precisely the sort of tree one would expect to find in Sir Arthur Conan Doyle's "Maple White Land" from The Lost World. It is a survivor, a relic from the early Jurassic; other ginkgo-like fossils date to an even earlier era. Ginkgo biloba was discovered by naturalist Engelbert Kaempfer in China, as so many of our "living fossils" have been, in 1691; over 400 years later, this sole-surviving ginkgo species now has a cosmopolitan dispersal as an ornamental tree with an ancient lineage. Botanist Peter Crane has written an excellent, comprehensive natural history of the ginkgo tree in Ginkgo: The Tree That Time Forgot (Yale University Press, copyright 2013). If you're interested in the story of this incredible survivor, then this is the book for you.

Just a couple days ago, after almost two months, the first Xanthorrhoea australis seedlings poked their pointy leaves out of the soil. As of this moment, six of the eight seeds appear to have germinated, which is a better ratio than I anticipated. Actually, I had started to wonder if the seeds were viable, or if I'd used an appropriate soil blend in which to germinate them. I guess I should have known that some seeds just take longer to germinate. As their name implies, these seedlings look for all the world like a tiny sprout of grass...perhaps with blades a bit more stiff and thick, but grass nonetheless. It will take as long as twenty years before Xanthorrhoea australis develops its characteristic trunk. I will try to post a picture of the seedlings in the near future. But, as I tell myself, this is what these will look like one day:

Xanthorrhoea australis. Photo courtesy of Australian Seed.

I borrowed this photograph from Australian Seed. They do ship internationally, according to their website, so if you can't source this amazing plant domestically, perhaps give them a try. It looks like Australian Seed carries the seeds of many other native (and unusual) Australian plants, so keep them in mind for these as well (I know I will). And, while the Ginkgo is a far better-known Mesozoic survivor, the family Xanthorrhea is ancient as well - it is possible that the Cretaceous saw the first Grass Trees growing in the soil of a fractured Gondwana.

Ephedra nevadensis and cold-stratification.

Last night I began cold-stratifying a small flat of six to eight Ephedra nevadensis. I have promised myself I will leave them in the refrigerator for the requisite 30 days. Unfortunately, the single seedling I managed to propagate last year appears to have succumbed to the elements (namely, my own distraction - it was not with my other seedlings and I missed watering it). A small pot in an arid climate can kill a seedling of even very xeric-adapted plants. It's still possible that the seedling is simply dormant, since they grow very slowly, but maybe not. Gardening is a learning experience, even if the learning curve is sometimes steep.

I also ordered packets of Ephedra intermedia and Ephedra equisetina (Bluestem Joint Fir), and I look forward to propagating these as well.

A reliably hardy palm for Colorado!

Yucca rostrata.

Okay, not really. But the tree yuccas are really cool, and Yucca rostrata 'Sapphire Skies' has a very tropical feel. Its upright habit and rigid leaves make it a striking specimen in the garden. 'Sapphire Skies' might be slightly hardier than the species. Its leaves are stiff, shorter than the species, and, according to Monrovia, "form a dense crown atop an elegant single trunk." Like most yuccas, Yucca rostrata is slow-growing, but it is likely one of the hardiest tree-like yucca species...and it is certainly one of the most beautiful. On the issue of hardiness, siting seems to be a significant contributor to success or failure. Depending on the source, Yucca rostrata 'Sapphire Skies' is hardy to USDA Zone 5b, while the species seems to be hardy to USDA Zone 6. Again, proper siting is key. Its soil should drain well and it should be in a location with full sun. In Colorado's dry climate, this would be an excellent candidate for the tropical garden.

Yucca rostrata 'Sapphire Skies'.
Courtesy of Monrovia.

Other hardy tree-like yuccas includeYucca elata, commonly called the Soaptree Yucca (hardy to USDA Zone 6a, though mine sailed through temperatures that dropped below -10 Fahrenheit this past winter), and the compact form of the famous Joshua Tree, Yucca brevifolia v. jaegeriana (reportedly hardy to USDA Zone 5). Even the standard form of Yucca brevifolia is hardy to USDA Zone 6a. Yucca torreyi (reportedly hardy to USDA Zone 5), Yucca faxoniana 'Giant Faxon' (from the northern population of the species, reportedly hardy to USDA Zone 5, though other sources indicate the species is only hardy to Zone 8; perhaps Yucca faxoniana is similar to Agave parryi, where different populations and subspecies can vary wildly in hardiness, but I digress), and Yucca schottii, the Mountain Yucca (hardy to USDA Zone 6a or maybe Zone 5b) are a few others that might prove marginal in Colorado but would work great in the right microclimate. Many of these species appear far more at home in an arid desert landscape, but Yucca rostrata lends itself to either the tropical or the desert garden, as would a mature grove of Yucca schottii. With marginal yuccas, perhaps the only way to know if a species is hardy in your garden is to try growing it. It is definitely worth it - these are amazing plants!

Yucca schottii. Photograph by Georges Jansoone.
This specimen looks for all the world like some species of Pandanus, minus the prop roots.

Conifers that evoke the tropics.

Conifers are iconic trees, though they are not necessarily what comes to mind when you picture a lost world. Of course, if you've seen BBC's Walking With Dinosaurs series, you've seen a tropical conifer island: New Caledonia. Podocarpaceae, Araucariaceae, and Cupressaceae make up a significant part of the flora on this relatively small splinter of ancient Gondwana. According to The Gymnosperm Database, New Caledonia holds 3 endemic conifer genera and 43 endemic conifer species. Actually, New Caledonia has no non-endemic conifers, and its conifer biodiversity is rivaled only by New Zealand (103,738 square miles), Sichuan (187,259 square miles), and California (163,696 square miles)...and, at a mere 7,172 square miles, New Caledonia is much smaller.

Brachiosaurus and Araucaria. From Walking with Dinosaurs miniseries.
Filmed in Patagonia (these trees are Araucaria araucana), as well as
Tasmania, California, and New Zealand.

So, how does a gardener capture the look of these tropical conifers in a temperate zone? Well, if you live in a more moderate climate (say, USDA zone 7-10 with sufficient rain), then you could always plant the hardier Auracaria araucana, or Monkey Puzzle Tree. They grow well in the boreal rainforest of the Pacific Northwest. However, in Colorado's USDA zone 5 the winters are simply too brutal. This is a land of extremes, and though I haven't tried killing any podocarps or araucaria yet, I doubt they would survive the frigid stretches of our average winter temperatures.

Back to the question. Does this mean there are no tropical-like conifers for Colorado? Well, with the right siting there might be a few...

Cryptomeria japonica 'Araucarioides'

Cryptomeria japonica 'Araucarioides'.

A cultivar of Japanese Cedar, the name says it all. Also known as the Whipcord Japanese Cedar, the needles are held tightly to the branches, giving it a very Araucaria-like look. Hardy to USDA Zones 5/6 through 9, the Whipcord Japanese Cedar is a perfect candidate for a pseudo-tropical garden. It should be situated away from drying winter winds, an important consideration in Colorado. Cryptomeria prefers moist, well-draining soil, and its growth is fastest in humus-rich soils. Not the conifer to plant if drought is a consideration, an equally important consideration in Colorado. Still, if these environmental conditions can be met, there is really no reason why Cryptomeria japonica 'Araucarioides' could not be attempted. Purported to remain much smaller than the species, the Whipcord Japanese Cedar should reach a height of 15 feet at maturity, its foliage increasing in fullness as it grows. Again, success with this conifer will undoubtedly be determined by microclimate and siting. Still, some sources do indicate that Cryptomeria can be drought-tolerant once established.

Pinus x schwerinii 'Wiethorst'.
Photograph by Sean Callahan,
American Conifer Society.

Pinus x schwerinii 'Wiethorst'
A cultivar originating from a witches' broom found on a hybrid between Pinus strobus (Eastern White Pine) and Pinus wallichiana (Bhutan Pine). Pinus strobus contributed an increased hardiness, Pinus wallichiana contributed long needles, and the witches' broom contributed a manageable size for smaller gardens. The longer, graceful needles are reminiscent of the tropical Central American pines and sub-tropical Mexican pines, so Pinus x schwerinni 'Wiethorst' definitely evokes the tropics. With space, the original Pinus x schwerinii could offer, albeit on a grander scale, the same effect as its dwarf clone. Pinus x schwerinii 'Weithorst' was one of two conifers chosen by the American Conifer Society as their 2014 Collectors Conifer of the Year.

Sciadopitys verticillata 'Sternschnuppe'
This is a narrow, upright cultivar of the Japanese Umbrella Pine, a monotypic genus whose fossil record dates back about 230 million years. Any Sciadopitys cultivar would make a stunning specimen conifer in the pseudo-tropical garden. Despite its exotic look, the Japanese Umbrella Pine is definitely not tropical. Hardy to USDA Zones 5 through 8, Sciadopitys verticillata, like Cryptomeria japonica, prefers moist, rich, well-drained soil in full sun, though it does prefer some afternoon shade in hot climates (during the summer, that'd be you, Colorado). It is a slow grower. The Missouri Botanical Garden cautions that it might "not be reliably winter hardy throughout USDA Zone 5", and suggest that it should be planted in a site protected from winter winds. Sciadopitys verticillata 'Sternschnuppe', commonly known as the Shooting Star Japanese Umbrella Pine, has thicker, broader, and shorter needles than the species, creating "a uniquely appealing texture not found in other conifers", according to Iseli Nursery. On the downside, this species can be subject to snow and ice damage during the winter, so it does require extra attention regarding snow loads. If snow is an issue (as it occasionally is here in Colorado), consider Sciadopitys verticillata 'Joe Kozey', another narrow cultivar purported to handle snow loads better due to its branches being sturdier and held closer to the trunk. Regardless of the cultivar, Sciadopitys is an amazing, ancient tree that never fails to garner attention in the garden.

Update on germinating Leucospermum cordifolium and Metasequoia glyptostroboides.

As of this evening, two of the Leucospermum cordifolium (Nodding Pincushion) seeds have germinated. What remains of their seed's outer shell is very hard, which makes me appreciate the hydrogen peroxide solution that they soaked in prior to planting. This solution, only about 1%, breaks down a clear (and presumably tough) outer coat on the already tough shell. The two seedlings are robust, though slow-growing.

Metasequoia forest in Cretaceous Montana. Artwork by Julius T. Csotonyi.

Metasequoia glyptostroboides (Dawn Redwood), on the other hand, appears to a far more delicate, tender seedling, though looks can be deceiving. The tallest of these seedlings is about a centimeter tall. As of this morning, only two of the seedlings have uncurled into an upright, vertical position; the remainder are still curled toward the soil, slowly unfurling upward. The protocol for germinating Dawn Redwood seeds is various and, occasionally, contradictory. I used an amalgamation of the commonest advice from reputable online sources, mostly adhering to the protocol published by Forest Research, a division of the Forestry Commission UK titled "Seed storage and pretreatment for Metasequoia glyptostroboides" (I've included the link here; also note their downloadable Raising Trees and Shrubs from Seed at the bottom of the page). I started by using a damp soil blend of 1:1:1:3 peat moss, perlite, sand, and potting soil in plastic pots, planting the seeds on the surface and covering with a dusting of fine potting soil. After planting the seeds, I placed each of the pots in ziploc bags in the refrigerator. These remained in the refrigerator for approximately five weeks, a shorter time than Forest Research recommends. Once I removed the pots from the ziploc bags, I placed them in a sunny window facing to the west. I've kept the soil damp (water from beneath) and misted the soil surface one to two times daily. Our house (as well as our climate) is far from humid, which is why I've suspected that misting the soil surface might be necessary. Thankfully, mold has not been an issue for me with this method, but I think that has more to do with clean seeds and soil, a shorter period of cold-stratification in the ziploc bags, and Colorado's typically low humidity.

What remains to be seen is how well Metasequoia glyptostroboides tolerates our seasonally xeric climate...and if I have room for such a potentially large tree in our narrow yard!

Finally, if you like Julius T. Csotonyi's paleoart in this post, you can check out his many works and purchase prints through his website here. He has some amazing artwork!

A fistful of penstemons.

About a month ago, three species of penstemon joined several other seeds in our spare refrigerator, though thankfully none of these require months of cold stratification. Around February 16th I began preparing two pots of Penstemon pinifolius (Pineleaf Penstemon) and one pot of Penstemon whippleanus (Whipple's Penstemon). On February 23rd I added six pots of Penstemon palmeri, commonly known as Palmer's Penstemon, Scented Penstemon, or Pink Wild Snapdragon. Penstemon palmeri will be planted alongside Ipomopsis rubra (Standing Cypress), and these two herbaceous plants will form part of the background for a collection of dwarf conifers, such as Picea pungens 'Globosa' and Thuja occidentalis 'Golden Globe'. I will post a picture once things get planted, but for now that part of the garden is still in preparation.

Since each of these penstemons require about four to eight weeks of cold stratification, they are just about ready to move to a warmer location. I will also begin germinating Ipomopsis rubra around the same time.

Penstemon palmeri. Photo by Stan Shebs.

Ipomopsis rubra by artist Ellis Rowan.

These native species will join several Penstemon 'Delft Blue Riding Hood' purchased last year from our local Lowes. And, since many penstemon species and cultivars seem to grow well in this climate, these will undoubtedly not be the last!

The first day of Spring.

And it was an absolutely beautiful day to be out and about in the garden! Despite an ever-present breeze, the temperature pushed 70 degrees Fahrenheit. Sorbaria sorbifolia (False Spiraea) is beginning to show its crimson feathery leaves, while Prunus salicina 'Toka' (Toka Plum) and Prunus armeniaca 'Moorpark' (Moorpark Apricot) are, thankfully, only starting to show some slight bud-swelling. After all, Colorado is notorious for late-spring frosts cold enough to wipe out an entire blossoming. Since these two trees were only planted last year, I don't expect significant fruiting, but I still don't want a late freeze to knock their buds off. Magnolia stellata 'Royal Star' (Royal Star Magnolia) is still holding large green buds, and I look forward to seeing if it flowers this year. Since it is growing in a cooler microclimate, I expect it to flower at least a bit later than if it were planted on the north side of the garden.

Earlier I wrote that I was uncertain whether or not the Chilopsis linearis seedling had made it through the winter. Apparently it has, a fact that I discovered when I tried to remove some sort of hard cocoon-like concretion (similar to a Megalopyge moth cocoon) from its lower stem - a small bit of the topmost layer of outer bark came off with the concretion, and it was definitely green beneath the outer bark. Since it doesn't look like the wound reached the cambium layer, I doubt the Desert Willow was damaged much by this. I'll just have to keep an eye on it.

Silene regia.

Most of the ferns have yet to reveal themselves, but the evergreen Adiantum venustum (Himalayan Maidenhair Fern) and Polystichum acrostichoides (Christmas Fern) look to have come through our harsh winter with only a little foliage damage.

Another plant that seems to have pulled through this winter is Silene regia (Royal Catchfly). They had a hard growing season last year, and I'm hoping that their new location (more consistent moisture, partial sun) will suit them better than the full sun location they were in last summer. Native to the disappearing tallgrass prairie of the American Midwest, this is a species of concern in many parts of the country.

There's still a great deal of work to be done, particularly with hardscaping pathways, dry stream beds, and other structural elements, but the garden has come a long way in the past year.

Acer grandidentatum.

Acer grandidentatum. Photograph by Cory Maylett.

A few days ago I began cold stratifying several Acer grandidentatum seeds. Commonly known as the Bigtooth Maple or Canyon Maple, Acer grandidentatum is closely related to the iconic Sugar Maple, Acer saccharum. Native to the interior western United States, the Bigtooth Maple is far better suited to our climate than many other maples. While not xeric, the Bigtooth Maple is reasonably tolerant of drought and, since it grows in limestone soils, is better suited to our typically alkaline soils. The leaves, though smaller than the impressive leaves of Acer macrophyllum (the Bigleaf Maple, a 50-70 foot monster of a tree native to the Pacific Northwest's boreal rain forests), are beautifully, deeply toothed. I've always liked maples, and I hope to include one or two of specimens of Acer grandidentatum in the garden, at least as space allows.

Acer grandidentatum leaves. Photograph by Cory Maylett.

Cool (but not cold) and windy - a perfect day for starting some seeds.

I've read conflicting reports as to whether or not Metasequoia glyptostroboides requires cold stratification for germination. However, since those who recommend it report increased success in germination, I've decided to follow their protocol: approximately six weeks of cold stratification, beginning today. I'm not exactly sure where I'll plant one - I don't really have room - but since it's one of my favorite trees, I just can't resist trying to grow one from seed. Maybe I can fit it in near the back of the garden...

That being said, Metasequoia can be a stunning bonsai specimen.

Tomorrow I'll be moving Penstemon palmeri into the refrigerator as well, but only for about a month. This species, with its six foot racemes should make a stunning background perennial behind the dwarf conifers. I plan on planting it alongside Ipomopsis rubra, or Standing Cypress, a biennial with stunning red flowers that should equal Penstemon palmeri in height. But Ipomopsis rubra, being from warmer regions of the United States, doesn't require cold stratification.

I also planted Xanthorrhoea australis, the Grass Tree, in a specially prepared soil mixture this afternoon. In the wild these plants grow in acidic, nutrient-poor soils that remain VERY dry. Overwatering seems to be the single significant reason for their demise in cultivation. Since these will not survive the winters here, the plan is to grow it as a container plant. It will likely take around thirty years to develop its characteristic trunk. In fact, the Xanthorrhoea australis on the postage stamp to the right may be several hundred years old. These amazing Australian plants have a very ancient lineage, not to mention a fascinating structure: the trunk of Xanthorrhoea is hollow, formed from accumulated leaf bases, with aerial roots running down its hollow center providing nutrient transport. This is the type of plant one might expect to encounter in a lost world!

Finally, I started soaking Leucospermum cordifolium seeds, which I will plant tomorrow. Commonly known as the Nodding Pincushion, this member of the family Proteaceae is absolutely stunning, as evidenced by the photograph below. Alas, this is another plant for container gardening in this climate. Like the Grass Tree, the Nodding Pincushion can easily handle our summers, but our winters are far too brutal, as evidenced by this past winter. Some Proteales might be marginal in our climate, but not Leucospermum cordifolium. Still, since this is my first attempt at germinating a Proteale, it's probably a good place to start.

Leucospermum cordifolium. Photograph by Cs california.

Since it was in the upper forties today, I did spend a couple hours outside. I think the Chilopsis linearis, or Desert Willow, might have come through the past few colder-than-usual winter months with relatively minor winter-kill. The Desert Willow, despite its name, is a relative of the Catalpa and a member of the family Bignoniaceae, as evidenced by the photo of its showy flowers below. It is considered marginal at best in our climate, so if this year-old plant survives this cold winter with what little protection I have been able to offer it, it is a hardy specimen indeed. For now I will simply have to wait and see (and continue to cover it during our really cold nights).

Chilopsis linearis. Photograph by Stan Shebs.

The carpet of Delosperma cooperi, commonly known as Hardy or Trailing Ice Plant, appears to have weathered the cold temperatures as well, though much of its succulent green has been replaced by winter's red. Penstemon barbatus 'Riding Hood Delft Blue' is still green beneath the accumulation of leaves that has served as protection. Not too bad for markdown plants from our local Lowes!

As I've mentioned, this winter has been colder than previous winters (in my limited experience), so I look forward to seeing what else rebounds in the spring. I'll keep you posted.

Ephedra nevadensis.

Late summer 2013 I managed to get a single Ephedra nevadensis to germinate. Germination would likely have been better had I used a longer period of cold stratification. That's something to remember when I sow the remainder this spring.

Ephedras are amazing plants, and rather primitive, with a lineage that tracks back to the Cretaceous period. Scrubby at first glance, ephedras are gymnosperms, a relationship hinted at in their common name: joint fir. Like conifers and cycads, these plants produce cones. They are typically found growing in extreme environments: deserts, scrub, dry mountains, and the like. They have a global distribution, from the mountains of South America to the dry American Southwest to the Far East of China, across Central Asia to the Middle East, south along the Red Sea and westward along both coasts of the Mediterranean Sea.

I hope to add a few more species to the gardens, perhaps Ephedra intermedia (used in Chinese medicine along with Ephedra sinica) or Ephedra equisetina - the Bluestem Joint Fir. Either of these would make striking additions to the rock garden.