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Orchid Intimidation

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Fear Not

I used to find orchids intimidating to grow. Their dust-sized seeds are fairly unique in not having any food reserves so — in the wild, at least — need the help of a fungus partner to get growing. And some orchids (epiphytes) spend their lives nestled in trees so need a special potting mix when grown in a pot. Orchids have above-ground structures called pseudobulbs. And many, especially those that call humid, tropical forests their homes, demand exacting environmental conditions that are very different from that found in most homes. Whew!

So I steered clear of growing any orchid for many years — until a local orchid enthusiast gave me a plant. After a couple of years, that plant, around this time of year, sent up a slender stalk which was soon punctuated with eight waxy, white flowers, each an inch across. For two months, those flowers greeted me each morning with their beauty and their delicious fragrance. Every year since, that plant has greeted me for weeks in midwinter.

Odontogl . . . a Mouthful

My orchid has no common name so needs to be referred to by its botanical mouthful, Odontoglossum pulchellum. (Even orchid names are intimidating, especially so because different genera have often been hybridized, and the resulting hybrid combines the generic names of the parents. So a hybrid with Brassavola, Laelia, and Cattleya in its parentage would have the name Brassolaeliocattleya. Now that’s a mouthful!)

Name notwithstanding, my Odontoglossum pulchellum has been easy to grow and get to flower. Odontoglossum pulchellum orchidThe plant spends summers outdoors in semi-shade near the north wall of my house, and winters indoors on a sunny windowsill. I water it perhaps twice a week, unless I forget.

Sounds like your run-of-the-mill houseplant, doesn’t it? So much for orchids being difficult.

The only special treatment my plant gets is a special potting mix. Odontoglossum pulchellum is an epiphytic orchard. Commercial potting mixes are available for epiphytic orchards but I make my own by mixing equal parts of my standard (home made) potting mix with equal parts wood chips. Nothing special about the chips; I just scoop them up from the pile that I use mostly for mulch that an arborist kindly dumps next to my woodshed every year.

Every spring I divide my orchid plant into 2 or 3 new plants, potting each new plant into its own pot with fresh potting mix.

More Orchids?

Odontoglossum pulchellum is an orchid that tolerates being treated like your average houseplant. And this is one of the most important points in growing orchids in a house: choose a sort that thrives in such an environment. Other orchids that will grow in the average home include phalaenopsis, paphiopedilums, and mini-catts, which are dwarf hybrids involving Cattleya (the corsage orchid).

Ideally, for flowering at least, certain conditions must be met. Most orchids enjoy bright light, which means setting the plant at an east, west, or south windowsill. From spring through autumn, light from a south window is too intense and may scorch foliage, so plants need to be protected with a thin gauze curtain, or moved to other windows or semi-shade outdoors.

Most orchids — again, for flowering — enjoy a ten to fifteen degree temperature difference from day to night, which is no problem in winter if you heat with a wood stove or already turn the thermostat down at night to conserve fuel. In the summer, the plant needs to be outdoors or else in a room that is not air-conditioned.

Even those orchids adapted to a home environment benefit from increased humidity. I raise the humidity around my plants by perching the flowerpot above a water-filled tray. Clustering plants together is another way to raise the humidity near plants, and also creates a visual lushness.

Once correctly sited, many orchids do not require inordinate amounts of care. Water requirements vary, but species with thickened pseudobulbs (bulbous stems), such as my Odontoglossum, get by with the least frequent watering. Orchid roots are susceptible to fertilizer burn, so the rule in feeding is to do it frequently and lightly. As with other houseplants, some orchid species take an annual rest, and at such times watering and feeding should commensurately diminish.

Since “mastering” the growing of one orchid, I have acquired another kind.Pink rock orchid This orchid is Dendrobium kingianum, which does go under the more user-friendly common name of pink rock orchid. I have also gotten this one to flower — but not every year.

HOUSEPLANTS THRIVE DURING MY CUBAN GETAWAY

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Water In Air, In Soil, In Reserve

My houseplants enjoyed my absence more that I expected. I thought it might be harder on them. After all, with spring in the air (indoors) for a few weeks now, they were all pushing out new shoots from the ends and along stems that had lain dormant all winter. Citrus, avocado, and amaryllis were even flowering, and rosemary was getting ready to flower.

Lack of water was going to be the threat, 5 days of it, while I was far away wandering up and down streets and in and out of alleys of Havana, Cuba.Havana street scene

Through winter, I had eased my houseplant watering chores by using “water siphons” (aka “hydrospikes” or “self-watering probes”). These porous ceramic probes, filled with water and pushed into the potting soil, have the thin, flexible tubes coming out of their caps plunked into mason jars filled with water. I knew well just how thirsty the plants were, watching the water in the reservoirs into which the tubes that connect to the ceramic cones drop daily, in some cases a cup or more per day.Automatic watering spikes

Plants cool off by letting water evaporate through little holes in their leaves, called stomates. So leaving the house thermostat set to cooler temperature was going to help slow water loss.

Evaporation is faster, whether through stomates or from the potting soil, the drier the air. Heat from radiators is less drying than that from the wood stove, our usual source of heat — also helping plants that might be pining away in my absence.

I poured water into the saucers in which each pot sits. As this water evaporates it creates a microclimate around nearby plants, a microclimate slightly more humid than that of the rest of the house, cutting down water loss from the potting soil and through the leaves. The humid microclimate was made more so by cozying plants in a cluster right up next to each other. Pebbles in the saucers bumped up this benefit by increasing the evaporative surface area.

To further help plants through their period of neglect, I filled the saucers with more water than usual, with the water level a smidgen above the bottom of the pots. As the potting mix dried, it could suck this water into the pot by capillary action. I don’t usually let water sit in the saucers above the level of the bottom of any resident pot because then the bottom of the pot becomes waterlogged, eventually leading to dead roots. I figured a few days would do no harm, and surely less harm than would drying out of the whole plant.

My final ministration was to cut open a clear dry cleaner bag and drape it loosely over the clusters of plants to maintain even higher humidity.Houseplants covered to maintain high humidity

The upshot: The plants did not miss me even a little. They looked healthy and happy upon my return, perhaps even more so than with five days of constant attention!

Visitando El Jardín Botánico Nacional

One day in Cuba I ventured beyond Havana for a tour of the Jardín Botánico Nacional, or National Botanical Garden, which is adjacent to Parque Lenin (Vladimir, not John) Park. We bounced along on a tractor-pulled wagon through a landscape devoted to plants native to Cuba, then on into a savannah of plants of African origin, to groupings of plants indigenous to Latin America, and on through other tropical climates and ecosystems.

A few greenhouses there create special environments. One was a tropical rainforest greenhouse, with humidity kept high with frequent, automatic watering. A houseplant such as maranta formed an expansive groundcover there, and other familiar houseplants, such as peperomia, philodendron, begonia,, and spathiphyllum, either spread all over the ground or reached heights you would never see in a house.

A dry greenhouse, the covering, this time, to shed rainfall, was home to succulents and cactii. One cactus that caught my attention, especially so with Cuba’s connection to the Soviet Union, was the “Russian soldier cactus.” The upper portion of this upright cactus was furry and brown, just like a Russian soldier’s hat. (As far as cool, common names the Cubans have for plants, another one was “tourist tree,” so-named for its red, peeling bark, just like the skin of pale tourists that get too much tropical sun.)Russian soldier cactus

Another Orchid!?

I’m very happy with my two orchid plants — Dendrobium kingianum, the pink rock orchid, and Odontoglossum pulchellum, lily-of-the-valley orchid. Both bloom reliably once a year, in winter, for over a month. 

But one of the orchids at the Jardín Botánico Nacional caught my attention for more than its beauty. Spathoglotis plicata, sometimes called Phillipine ground orchid, blossoms all year ‘round. It’s a terrestrial orchid that’s also easy to grow, not needing an excess of light. I’m going to get one to add to my collection.Spathoglottis orchid

Orchids can become an obsession; I hope I’m not about to fall down a rabbit hole.

EVERYTHING’S EASY, FOR NOW

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An Easy Orchid

Orchids are one group of plants I’ve regularly sidestepped. It seemed to me that if you grew orchids, you became crazed over orchids, to the exclusion of other plants. You then fill your home with as many of the over 20,000 species as you can cram onto your windowsills. I feared being led down that path.

My sidestepping took a turn into orchid-land 25 years ago when a local orchid enthusiast gave me a plant of Odontoglossum pulchellum, which I today learned has also been called lily-of-the-valley orchid. But more importantly today, the plant is in bloom. Blossoms from this plant are no rare occurrence; it’s bloomed every year for about the past 20 years, some years around now and other years waiting until February to unfold.Odontoglossum pulchellum orchid

Odontoglossum pulchellum doesn’t sport knock-your-socks-off, traffic-stopping blossoms; instead, they have a soft, subtle beauty. Right now, delicate, arching flower stems rise up from clusters of torpedo-shaped, green pseudobulbs that are perched up out of the “soil.” Eight to 10 dainty, waxy, white blossoms line up along each flowering stem and waft a sweet fragrance, more like paper-whites than lily-of-the-valley to me, that transports me to spring.

I get all this for very little effort and without becoming orchid-crazy. For years, I didn’t know the name of my plants so couldn’t even look up how to grow them. Rather than pot them up in any special orchid soil, I merely mix an equal volume of wood chips from my outdoor pile into my regular, homemade potting soil, along with a bit of soybean meal for extra nitrogen. I keep the plants in a sunny window in winter and sometimes move them outdoors in summer, dividing and repotting the pseudobulbs to make new plants.

For this bit of effort, I get fragrant, white blossoms every winter, and they last for at least a month. Odontoglossum pulchellum is easy to multiply yet I’ve happily managed to restrain myself to keeping only 3 or 4 plants after I’ve divided and repotted them each spring.

Easy Celery

Growing good celery demands a gardener’s greatest skill, and this year, in the greenhouse, I have the finest celery I’ve ever tasted or grown. The stalks are large, thick, juicy, even a little sweet. Unfortunately, I’m not sure I can take credit for this horticultural achievement.

Every summer I sow celery seed to transplant into my minimally heated greenhouse to provide stalks for salads and soups throughout winter. I do take credit for selecting a good variety: Ventura. I also take credit for providing good soil conditions; each year I slather an inch or so of ripe compost on all the beds in the greenhouse. And I’ll take credit for providing timely watering, with drip irrigation until a couple of weeks ago and by hand through winter.Self-sown Ventura celery

Ventura is an open-pollinated, rather than a hybrid, variety, which means that I can save my own seed for replanting each year. Beginning a few years ago, I’d allow one or two of the greenhouse Ventura plants that began to form flower umbels to do their thing and make seed, which they did prodigiously. I’d collect seed for planting the following season’s outdoor and indoor celery.

Some of those seeds would drop to the ground and germinate right in the greenhouse. These “volunteers” sometimes grew into seedlings as good or better than the plants I would later transplant back into the greenhouse.

So a couple of years ago I decided to let the celery self-sow freely in the greenhouse. Later in winter, I’ll transplant some of those seedlings into pots for eventual planting out in the garden.

In the greenhouse, I thin out excess seedlings, keeping the largest ones, which are already large enough for harvest. The stalks, especially welcome in winter, are, as I wrote above, “large, thick, juicy, even a little sweet.” I like to think I had a hand in horticultural achievement.

And Nothing To Do (For Now)

Nothing like a little snowfall to clean everything up in the garden. December 11th was the date of the first snow, followed by a second one on the 17th. The white blankets covered the pile of crocosmia leaves lying on the ground and waiting to be carted over to the compost bin, some weeds that sprouted in the mulched area beneath the dwarf apples, some of the smaller plants I haven’t yet cleared from vegetable beds, and numerous other messy distractions. The whole view was knit together in the sea of whiteness.Winter garden scene

Spells of warmer weather and bright sunshine have eroded away some of the snow, mostly taking the fluffy, white lines and dots that rested atop fences and their fenceposts. The ground, as I write, is still pretty much covered in a white blanket. While I’m enjoying the wintry scene, I can forget about about the few odd jobs still left to do that are patiently waiting beneath the the snow.

Pink rock orchid

Of Orchids and Oil

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Over the past few weeks, excitement was steadily mounting on the windowsill. First came the stalk that poked up from the bases of whorls of leathery leaves. Then, buds started fattening up along the stalks. Finally, after a half a decade of growing Dendrobium kingianum, the pink rock orchid, it looked like the plant might finally reward me with some blossoms. Which it did, a couple of days ago.
The actual blossoming was somewhat anticlimactic. No flamboyant shapes or colors, just small, white blossoms. And no particularly green thumb was required to get this orchid to blossom, just time.
Pink rock orchid is known to be a tough plant. While many orchids are native to lush, tropical jungles, the conditions of which are hard to  even approach, indoors except in a hothouse, this orchid is native to rocky environments of Australia. It tolerates cold below freezing and hot temperatures over 100°F., and does not demand an inordinate amount of light. I water whenever the potting mix seems dry.

The problem is that “orchid flowering” conjures up both a greater challenge and blossoms more spectacular than are offered by pink rock orchid. So I’m now just going to look upon it as an attractive houseplant with an attractive flower. It even has a pleasant, slight scent.
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I’ve waxed enthusiastic about the handfuls of ripe figs I gather up in late summer and into fall from my greenhouse. And about heads of lettuce and mâche, celery stalks, and sprigs of parsley that fill salad bowls all winter. Yet all is not always so Eden-like within the greenhouse. Last year scale insects began to attack a couple of fig trees. Innocuous-looking, small bumps on the bark — dormant scale insects — threaten to wake up in a larger outbreak this year. Action is needed. Now.
Last year at this time my weapon was an old toothbrush and a solution of soapy water. The brute force method of scrubbing the insects from the bark was effective — to a point — but tedious.
This year I’m smothering the buggers. My weapon of choice is oil, not any old oil but a specially refined oil that minimizes damage to plants while leaving insects gasping for air. It also contains an emulsifier so it readily mixes with water. Spray oil comes in two “flavors:” dormant oil and summer oil. Plants are more likely to be damaged by oil when they are in leaf and growing, so summer oils are more refined; summer oils mixed at higher concentrations can be used as dormant oils. (Summer oils are also called “horticultural oils,” “stylet oils,” or “ultrafine oils.”)
Oil sprays have been around for a long time — commercially for over a hundred years — and have the advantages of causing little harm to beneficial organisms and being relatively safe for birds, humans, and other mammals. Insects and mites (which oils also control) have little likelihood of developing resistance to oil sprays. The oils might be petroleum-, plant-, or fish-based.

So what’s not to like about oil sprays? Most importantly, they can damage plants. To avoid damage, sprays must be applied when temperatures are above freezing but not too, too hot, say above 90°F. Also, some plants, such as Japanese maple, redbud, azalea, hibiscus, and sugar maple, are readily damaged by oil; and oil will strip the blue, waxy coating from Colorado blue spruce, turning the needles green. The longer any plant is coated with oil, the more chance for damage; low humidity hastens its evaporation.  
Spray oils work by direct contact, which is advantageous unless you have a pest whose eggs are resistant to oil and keep hatching over time. Or if the pest flies in from elsewhere. Many gardeners routinely spray their fruit trees in spring with oil, with little effect because the most significant pests of fruit trees generally do not hang out on the stems or fruits for long enough for a direct hit by an oil spray.
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Back to the fig trees in my greenhouse. They’re getting weekly sprays of dormant strength summer oil until the leaves begin to unfold. Once that happens, I may mix up a batch of summer strength oil. The goal is to reduce populations drastically because, despite the innocuousness of oil sprays, I’d rather not spray anything once fruits begin to develop.
My other tack to keep scale insects at bay is to wrap the trunk with a band of masking tape coated with sticky Tangletrap, providing a Maginot line to stop ants from climbing the trees. (Hopefully, more effective than the real Maginot line.) Ants enjoy the sweet honeydew exuded by the scale insects and, in return, herd them, protecting them from predators.
Spraying and banding may seem like a lot of effort. But fresh figs are worth it. And with snow still on the ground, there’s not that much else to do, gardenwise, yet this time of year.

Nothing To Do

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If the garden, indoors and out, has no need of my attention at any time of year, it is now. I probably shouldn’t even be writing anything about gardening because pretty much nothing is going on. So I’ll make this brief.
Lack of light, warmth, and/or enough cool temperatures are keeping plants quiescent or dormant. The bonsai weeping fig, the Maid of Orleans jasmine (Jasminum sambac), the rose geranium, and other

Bonsai weeping fig, biding its time, for now

houseplants aren’t waiting for warmth. They’re indoors. These tropical plants never experience true dormancy; they’re quiescent, just sitting and waiting for better growing conditions, in this case more light.

My amaryllis bulbs aren’t waiting for brighter days. They’re now leafless, so can’t see the light anyway. Like the above houseplants, the amaryllis bulbs are now also quiescent, in this case from lack of warmth. Yes, it’s warm in my home, but not in the basement where the potted bulbs have been residing. I’ve brought the first pot of amaryllises upstairs where warmth — and water, the lack of which also has kept the bulbs purposely quiescent — can prod the bulb awake.
What about lack of enough cool temperatures to kickstart plants? That’s the case, now, with trees and shrubs outside. These plants are dormant, held back not by lack of warmth or water but by their internal physiology that needs to be switched before they’ll respond to good growing conditions.
No petals will unfold nor buds expand into young shoots until these plants are convinced that winter is over. That recognition comes after the plant experiences a period of cool — not frigid, temperatures — in the range of about 30° to 45°F. Winter’s “over” for these plants after about 1,000 total hours of exposure to cool temperatures, although the amount can vary among kinds of plants, even varieties of the same kind of plant. Also, a spell of midwinter warm weather can have the effect of removing hours from the “chilling bank.”
So what’s a gardener to do now? Nothing.
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Okay, not everything green is just biding its time. Some tropical flowers take the opportunity to blossom this time of year, even if the plants might be otherwise quiescent.  Hence, we have holiday poinsettias and Christmas cactii sporting their red, pink, or white blossoms.
Not that poinsettia and Christmas cactus flowers will blossom willy nilly. As with trees and shrubs outdoors, these tropical flowers can be prodded to blossom with certain environmental conditions. They don’t know from cold, except that it damages them, so what they need to flower is a change in photoperiod. For late December blossoming, poinsettia needs 6 weeks of 15-hour-long nights uninterrupted by any light at all. Even a table lamp or a flashlight.
Christmas cactus behaves similarly, with an additional wrinkle. If temperatures are cool, in the 50’s, daylength (or, more properly, nightlength, because it’s the length of dark period to which the plants are responding) is immaterial. Plants will flower. If temperatures are warm, in the 70’s, daylength is similarly immaterial. Plants will NOT flower. With temperatures in the 60’s, plants will flower only after a period of 11-hour-long nights.
After a number of years of annual bloom, my poinsettia died, last summer. I got rid of my Christmas cactus many years ago to prevent its infestation of scale insects from spreading to other houseplants. I’ll eventually replace both but for now, there’s still nothing for me to do, gardenwise.
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One plant that responds to some environmental condition, but I’m not sure what, is my orchid, the botanical mouthful Odontoglossum pulchellum. Every winter, sometime between the end of December and

February, my potted plant sends up thin flower stalks along which sprout white flowers whose thick petals look as if they were carved from wax and from which drifts a delicate fragrance. Blooms persist relentlessly, for weeks. The plants only flower in winter, but I’m not sure what exactly brings on the flowering.

After petals finally fall, the plants can take a rest, so need very little watering. The same goes for poinsettia and Christmas cactus plants. By then, of course, it’s late winter so seeds need to be sown and seedlings transplanted indoors, trees and shrubs need pruning, and there’s plenty of other stuff to do, gardenwise.