Wildest Dreams of Kew

Still the world is wondrous large,--seven seas from marge to marge,--And it holds a vast of various kinds of man; And the wildest dreams of Kew are the facts of Khatmandhu --Rudyard Kipling, In the Neolithic Age


This has been an interesting life. I've learned a lot of lessons the hard way.

Monday, December 06, 2004

Iris unguicularis, the winter-blooming Iris

One of my favorite winter-blooming plants has been unlucky for me. I keep losing Iris unguicularis to unrelated mishaps, one after another. I had nice big clumps of it one year, and some renters carefully, systematically, dug every last rhizome out of the ground, having decided it was a weed. Another year, the division I bought never took. I think the growers were too optimistic about how viable their miserly starts were. It's not the plant's fault; actually it's pretty tough, if unlucky.

It does have at least one fault: the blossoms are perched on nothing but the ends of their floral tubes, like Crocus, leaving the flowers too close to the ground, especially compared to the leaves. When it is blooming well, there are enough of them to stand out even with the overhanging foliage.

The blossoms vary in color; I have had, and prefer, varieties with saturated bluish-purple blossoms. Some varieties have washed-out blossoms, and I don't want those. Anything that blooms in winter had better have colorful blossoms if I am to notice them. To help attract attention, they happen to be quite fragrant. The main component of their fragrance is the elusive scent of ionine, the same chemical as found in sweet violets. A peculiarity of this fragrance is that human noses can only smell it for a few seconds at a time; then our smell receptors desensitize to it.

The plant is surprisingly hardy; it has been known to survive on Long Island (USDA z7). The blossoms, however, are fairly delicate as winter-bloomers go; it's more likely to bloom in USDA zones 8 and 9. Frost does ruin them, but the plant will keep making more buds, so you get bursts of flowers in each winter mild spell, and then a brilliant finale by late winter or early spring. It's one of the showiest winter-blooming plants you can grow in a climate like Seattle's or London's, with flowers that are prettier and more coloful than those of most winterbloomers.

The leaves are leathery and evergreen, making nice clumps of strappy foliage.

Last year I bought another one. It didn't grow much this year but it is a little better-established and seems to be viable now. Wish me luck!

Oxalis comosa

I have some interesting bulbs planned for next year. I had to pot some of them up, because they weren't well established and their hardiness is in question.

One of these is Oxalis comosa. Unfortunately I don't have my own photos but you can look them up on the Internet (just follow the link). It has large blossoms out of scale with the small leaves, in tropical shades of yellow, salmon, and pink. Like many Oxalis, it is a native of South Africa, where the Mediterranean climate encourages many plants including this one to come up in the autumn, live over the mild and rainy winter, bloom generously in the spring, and do dormant during the dry summer.

Its going to live in a rock garden that turns hot and sunny in the summer. Its neighbors include a lot of southern-hemisphere natives, including a lot of fellow South Africans like Osteospermum barberae compactum, Diascia vigilis, and Agapanthus 'Stormcloud'. It should be one of the first to bloom, and once established the flower show should be quite good.

Tuesday, November 23, 2004

Autumnal armchair gardening

One of the fun activities of gloomy Autumn days is planning next year's garden. I'm ordering a few seeds by mailorder. That's where you can find the widest variety anymore; garden center seed racks have become a bit sparce in recent decades. One of the wost problems with seed-rack seeds is that “one size fits all” in terms of climactic suitability. Don't be surprised to see watermelon seed in Maine or spinach seed for Arizona.

I live where summers are cool. I like to have a variety of warm-weather and cool-weather crops, so I plan my warm-weather crops to be of relatively tolerant varieties. Usually, but not always, varieties bred to be extra-early tend to be the best bets for cooler climates. Tomato 'Sub-Arctic Plenty', which was bred for producing tomatoes at an Arctic military base, reliably ripens its crop even in places like the Pacific Northwest or the British Isles. There are also corn and melon varieties bred for short or cool summers. Sometimes a cold frame is the way to go; then you can also grow lettuce in the winter in many climates.

I take the issue of “peak oil” (demand for petroleum outrunning supply due to exhaustion of supplies) very seriously. It takes roughly 10 calories of fuel to raise 1 calorie of grain. It takes roughly 10 calories of grain to produce 1 calorie of meat. I don't eat meat, so don't blame me! Unfortunately the odds are still against me.

That's why I give plenty of thought about how to raise fruits and vegetables without extravagant use of fertilizers, irrigation. Of course you can only get out what is put in: potatoes for instance will grow on nitrogen-deficient soils, but they are low in protein. Creating protein requires nitrogen. Leguminous crops can fix nitrogen from the air, so they are a good deal.

Some crops are much easier to raise than others, all other factors being the same. Tomatoes are popular partly because they are easy almost anywhere except where summers are too cold, too short, or very hot. Zucchini is so easy it has a reputation for excess! Celery is tricky to grow unless you're not picky about the possibility of small, parsley-like stalks. Cauliflower is apt to produce small heads when grown my amateurs. A lot of crops that are easy in cool, moist weather turn bitter and bolt to seed in hot weather. I like a lot of different vegetables so I can be satisfied with what is easy to grow and what is available in each season.

Because I plan to save seed, I'm avoiding so-called "F1 hybrids" in favor of seed that breeds true. Obviously, I won't touch patented seed. I am worried that in the near future, public domain plant genetics will dry up and be replaced by patented seeds. Think of heirloom vegetable seed as “green gold”.

Sunday, November 21, 2004

Vireya blooming in the cold fog

Below is a photo of a Vireya Rhododendron that is currently blooming on my deck. Vireyas can bloom about any time of year. It's a hybrid that was bred by Jim Gerdemann in Yachats, Oregon. It's called “Tropic Alpine Gold”. The plant is just a rooted cutting and is blooming in a 4 inch pot. It's very cute. Mr. Gerdemann bred it for hardiness, which is generally lacking in Vireyas. This one can probably stand temperatures somewhere down in the range of -5C to -7C.

Rhododendron 'Tropic Alpine Gold'

Tuesday, November 16, 2004

Tree Dahlias

Dahlia imperialis is trying to bloom for me. It will be a race against dampness and the possibility of frost. So far, so good, but some mild sunny weather would help. Maybe it will do better next year.

This is one of those completely herbaceous plants on a tree-like scale. It can easily hit 6 meters and I think I have actually seen taller than that. But each year all of that growth will be sacrificed, and the plant dies back to the fleshy roots. Like other Dahlias, its fat roots are not really tubers. If one breaks off it won't regrow, and if the stem dies or the buds die, the plant is dead.

What's the use of growing a perennial the size of a tree? Well, it's just different-looking in an appealing sort of way. If you ever wanted your own fairy woodland, this would be a good “tree” for it. Grow a bunch of them, at least a small grove. The stems are vaguely cane-like, and the ferny leaves big and twice-divided. The flowers are a pale shade of purplish-rose, and are reputedly fragrant like vanilla cookies. I'll have to take hearsay as a matter of faith, because they are far too high above my head to have any hope of smelling them. I've noticed vanilla cookie fragrance in other Dahlias, tho. This would be a fun plant to grow if you happened to have a terrace or balcony above it at just the right height to enjoy the flowers.

Not quite as big, but beautiful in perhaps an even more unusual way is Dahlia tenuicaulis. It's “only” about 4 meters tall, but it blooms more reliably than its bigger cousin, and the foliage has an unusual and striking light purple cast to it, especially on the newer leaves.

These tree-like Dahlias are native to the highlands of southern Mexico and northern Guatamala. The elevation and cloudcover keep summers cool, while being in the tropics keeps winters relatively mild for the elevation. They are adapted to the northwestern USA, some of the cooler parts of the southeastern USA, and much of maritime western Europe, wherever their hybrid cousins grow. They need good drainage to get through our wet winters, and vigilant protection from slugs in the spring when their shoots are trying to come up. Slugs are probably their biggest enemy, because they can actually kill the plants by destroying the new shoots. Otherwise, they are easy to grow in typical garden conditions, in full sun and fertile, well-aerated soil (a slightly sandy loam is good).

Sunday, November 14, 2004

Fuchsias still going strong

Grey autumnal days are when I most appreciate a few blossoms. Fall is somewhat of an odd time to bloom, because then plants have to try to ripen their seeds right through the middle of winter. There aren't a lot of pollinators available this time of year, either.Bright red, tubular blossoms attract Anna's Hummingbird, which overwinters along the West Coast even as far north as southwestern Canada. It's a tough little hummingbird that looks for trees bleeding sap to feed on while flowers are sparce.

I still have a few flowers it likes, Fuchsias among others. Most of them start blooming in summer, but a few particularly hardy ones that don't freeze back are already blooming by late spring. Fuchsias then obligingly bloom all the way into winter, until the first hard frosts. This year was hot and dry, so they are blooming better now than they did in the summer.

I have a lot of Fuchsias, both hybrids and species. Wild Fuchsias usually come in only a few vivid colors, with scarlet sepals and tube and a deep purple corolla being the most common combination. Hybrids, which sometimes have enormous flowers compared to the species, often come in pastels, and sometimes in unusual shades like pale purple, hot purple, candy pink, raspberry, and even a few salmons approaching orange. The species are the real troopers, though, still blooming heavily while the hybrids are only trickling out an occassional blossom anymore. I'll write more about hybrid Fuchsias when they are at their peak in late summer.

Fuchsia campos-portoi is one of the hardiest of the species. Less vigorous than its better-known Chilean counterpart F. magellanica, it has smaller leaves and flowers but otherwise looks about the same. Doesn't root as easily, unfortunately, so it will probably stay rare in cultivation. F. magellanica itself has a huge range in its native Chile and adjacent areas of Argentina, and surprisingly doesn't vary much except at the extremes. I do have a few distinct forms, including var. molinae, which has pale purplish-pink and mauve flowers and daintier, lighter green foliage than most forms; it also happens to be noticeably hardier than most, never freezing back in Seattle. Visitors to my garden sometimes express amazement that there are Fuchsias that get big enough to walk under; since the wood isn't very strong or long-lived, it never gets bigger than just that. Sometimes I have to prune them to prevent the soft wood from giving under too much weight.

I can't tell the difference between F. hatschbachii and F. regia. Both are clambering species from Brazil that grow long, slender branches reaching up into trees or shrubs for support. Both are quite cold-hardy despite coming from a subtropical climate.

F. thymifolia is one of several similar species from the cloudforests of southern Mexico. Like its close relations, it has tiny blossoms with inconspicuous sepals, a twiggy habit, and fine, almost ferny foliage on a potentially quite large shrub. It occassionally freezes back, but not every winter. Its a tough species, suitable for a number of purposes. You can even grow it in a rock garden as it will take quite a bit of sun once it hardens off.

Saturday, November 13, 2004

Arum creticum

Arum creticum has shown up in the catalogs of a few bulb dealers, and also in a few nurseries local to me. I don't think that it is hardy enough avoid damage in climates much colder than about USDA zone 8 or so, but where it is hardy, it's a useful plant like other species of Arum.

Arums are generally natives of mediterranean or maritime climates, and they leaf out early, most of them in the Autumn, and go dormant during the summer. In my own maritime climate, that means I don't have to irrigate them. It also means that their leaves will help hold down weeds during the winter, and prevent bare muddy soil when other things go dormant. For that reason I like to interplant them with things that are winter-dormant.

Arums often have smelly flowers but the scent is usually not particularly appealing; at best they smell like mushrooms or compost and at worst they are downright stinky. Arum creticum stands out for having blossoms that are not only more colorful than those of other Arums, being yellow or off-white instead of plain green or some lurid color like dark dull purple, but they also happen to be pleasingly fragrant. The spadix (the “Jack” that stands in the “Pulpit”) is either yellow or purple. Overall, the blossom looks very much like that of a Zantedeschia, otherwise known as a “Calla Lily”. All the specimens of it I have seen have plain green leaves, without the patterns of species such as Arum italicum.

I'm trying it in a few different spots. In one spot it will take over for Hedychium greenei when it freezes back in the winter, and in another spot it will take over for Pelargonium sideroides in a rock garden. Going dormant in the summer, it doesn't mind exposed situations like that.

I haven't had it long enough to comment about its exact cultural requirements, but it seems to be happy so far. I suspect it is probably a bit more sun-loving than its more northerly relations, but otherwise seems tolerant just like they are. I've got them in richer soil than they probably need.

Arum creticum is native to the islands of Crete, Karpathos, Rhodes, and Samos, where it grows on rocky hillsides.

Wednesday, November 10, 2004

Hong Kong

Some years ago I visited my in-laws in Hong Kong. Hong Kong is a small and densely-populated, but because its hills are steep and rocky, and the soil poor for farming, they were never disturbed much except for collecting firewood. There are still large expanses of mostly undeveloped land, about 60% of the colony's total. Hong Kong is a refuge for plants (and a few animals) as well as people.

The native habitats in Hong Kong are typically scrub on rocky hillsides, jungle, and low open woods. Frequent typhoons probably prevent tall forest from ever getting established.

China sits at a fairly low latitude, and mountains and deserts prevented the ice sheets from disturbing the flora during the Ice Ages. Although thousands of years of farming have wiped out most of the native vegetation on arable land, the remaining flora is richer in species than Europe or most of North America.

Some of China's most interesting plants are relicts (plants that have been reduced to small populations, often as a result of climate change). Several of Hong Kong's native Rhododendrons fall into this category. They survive on the hills, which, catching the cold front that spills out from the north in the winter, are noticeably cooler than the lowlands; on rare occassions they are coated with frost, despite sitting in the tropics and not being all that high.

Rhododendron hongkongensis is the rarest of the relict species; it has been found in only 6 locations in Hong Kong and neighboring Guangzhou province. It looks like and is closely-related to R. ovatum. It doesn't look much like the Rhododendrons most gardeners are familiar with; it's a member of the Azaleastrum Series. They're not Azaleas, but they are somewhat intermediate between Azaleas and other Rhododendrons, with fairly open, almost flat-faced flowers. Some of them including this one are mildly fragrant. I didn't see this one in Hong Kong (it would be hard to find) but I actually have a specimen courtesy of the Rhododendron Species Foundation. Although technically a tropical plant in the sense of being native to the tropics (Hong Kong is just south of the Tropic of Cancer), it is hardy in Seattle.

Another Rhododendron you might be lucky to spot in the undergrowth of the jungle growing on Victoria Peak is R. championiae. This one is a member of the Choniastrum Section, related to the Azaleastrums and mostly found in the Asian tropics. Many of them are fragrant. A few of them are surprisingly hardy to cold, but I don't know how hardy this one is.

Both of the preceding Rhododendrons look somewhat like Azaleas, but Hong Kong has a few real Azaleas, such as R. simsii. This species with medium-sized bright carmine blossoms is widespread and common in south and southwestern China to northern Burma and Thailand. It is believed to be one of the ancestors of the Belgian Indica Azaleas that are grown in hothouses, but some forms of R. simsii are hardy enough to grow in the Pacific Northwest as well as the southeastern USA. In Hong Kong you can see it on some of the hills.

An Azalea I saw in cultivation in Hong Kong has quite large purple flowers in early winter. It looks a lot like some of the Southern Indica Azaleas and is probably related. It must be very heat tolerant, whereas it was growing near sea level in the hot, humid city.

Native conifers are dying out, probably because of the heat. I saw scrubby pines growing on the hills and even a few Chamaecyparis here and there. More common in cultivation is Araucaria heterophylla, from Norfolk Island. This strange Gondwanic conifer is usually seen in the USA and Europe as a houseplant, but in south China it reaches its full size, when it assumes a fastigiate shape vaguely like that of a Lombardy Poplar. One common conifer that might be native (somewhere in south China, anyway) is Podocarpus chinensis, which looks like a shrubbier, smaller-leaved version of P. macrophyllus; they are probably just different forms of the same species. Growing in the hot, humid tropics it would seem as though it should be tender, but many gardeners in the southeastern USA claim it is actually slightly hardier than the already surprisingly hardy P. macrophyllus.

What most people mistake for conifers in Hong Kong are more likely to be species of Casaurina, strange Equisetum-like trees from Australia. They are not conifers, and they are not closely related to anything else. Eucalyptus is another common import from Australia.

Schefflera octophylla is common. It occurs in cultivation but is more common in the understory of the native low jungle. It's a small tree in size, with modest-sized leaves, and otherwise looks like a typical Schefflera. I don't know how hardy it is, but some of southwestern China's Scheffleras are hardy enough for temperate maritime climates such as in the Pacific Northwest of North America and coastal western Europe.

Another common plant with Gondwanic affinities is Dianella ensifolia. It is not as large or pretty as D. tasmanica, lacking the intensity of color of flower and berries, but it lives in a much hotter climate, and might be suitable for breeding heat-tolerant architectural plants for places like the southeastern USA. It grows in open woods and under scrub.

In the winter, the hills of Hong Kong Island are cheerful with the white blossoms of a Camellia-like plant. I think it's actually a species of Gordonia, although Camellias do occur in Hong Kong. The only Camellias I saw were at the Hong Kong botanical gardens, and they were in poor shape.

Gardenia jasminoides occurs wild in Hong Kong. Compared to domesticated plants, these tend to have large, single flowers. The produce a fruit (probably not palatable) that is used in Chinese herbal medicine.

Hong Kong does not have many native palms, but the Rhapis palms are probably native (if not to Hong Kong then probably nearby), as well as perhaps Caryota ochlandra which is common in cultivation. Other species of Caryotas are rare but I did see a few. Coconut palms (Cocus nucifera) are not particularly common but I did see a few stunted specimens; Hong Kong actually gets too cold for them in the winter but because the lowlands are essentially frostless they survive even if they don't thrive. Trachycarpus palms which are common elsewhere in China don't seem to occur in Hong Kong at all; it is probably too hot for them for most of the year.

Hong Kong also has vast numbers of non-native plants which have escaped cultivation. They are too many to name, most of them are tropical and quite tender, and they tend to be the same plants that are now pan-tropical.

One of the most conspicuous is Bauhinia x blakeana, with enormous blossoms whose fragrance mixes with the street smells to give much of Hong Kong a characteristic odor of perfumey, exotic incense mixed with sewage. The blossoms of B. x blakeana are the floral emblem of Hong Kong, and an image of one occurs on the local flag. It is called the "Hong Kong Orchid Tree", and perhaps was bred there by crossing two different species, but I don't think either of its parents is a native of Hong Kong. It seems to be quite sterile, as the trees never seem to have any pods, but one of its parents, with smaller, less showy blossoms, does go to seed.

Bo trees, Ficus religiosa, are quite common and reach surprisingly large sizes for a climate with typhoons. They were probably brought by Buddhists, for this is the tree that the Buddha was sitting under when he achieved Satori; the name "Bo" is derived from "Boda", which is usually transliterated as "Buddha" (I think "Boda", with a palatalized "d", is closer).

While Hong Kong is surprisingly well landscaped, there isn't much variety of native or exotic plants in most of its parks. The gardens in the old British colonial parks are an exception; that's where you can see a great many exotic species and they are worth visiting. Although small and now surrounded by millions of people they are in good condition.