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Future Hopes

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 Totipotentiality (Is This a Word?)

I was so excited one day a few years back to receive a box full of leafless sticks by mail. The exciting thing about those sticks was that each one of them could grow into a whole new plant from whose branches would eventually hang luscious apples and grapes.Grape cuttings

  And how did I know the fruits will be luscious? Because a year prior I was at an experimental orchard getting fruit photos for a book I was working on. Of course, I couldn’t help but also taste the fruits, and that’s why Chestnut Crab, Honeygold, Mollie’s Delicious, and King of the Pippins joined the two dozen or so other varieties of apples I already grew. Cayuga White, Bertille Seyve 2758, Steuben, Lakemont, Wapanuka, Himrod, Romulus, and Venus joined my grapes.

  It was “totipotence” – of the plants, not me – that allowed me to unlock potential treasures within those mailed sticks. Within a plant, every cell except for reproductive cells has the potential to become a root, a shoot, a flower, a thorn, a fruit, or any other part of a plant. For that matter, the same is true for humans and other animals. All that’s needed are the right conditions to get the various parts to grow – and there’s the rub.

  A little art and science puts totipotence to work. In the case of the apples, I grafted those stems onto my existing trees or onto small rootstocks. Existing trees or rootstocks provide nothing more than roots to nourish shoots that will eventually sprout from the sticks. The plant beyond the graft remains genetically that of whatever variety is grafted upon the rootstock. Bark graftGrape sticks got plunged into the ground where they grew their own roots, shoots, and everything else. Apples aren’t so amenable to growing their own roots.

  I generally wait to graft or set cuttings until early spring. Warmth awakens those sticks. Until then, they’re kept cool and dormant.

  I planned on tasting the first fruits of my labors within about 3 years.

Out With the New, In With the Newer

None of those varieties I received as leafless sticks are still with me.

Because of pests, apples are especially problematic to grow here so I subsequently narrowed down my apple holdings to trees of my few very favorite varieties: Macoun, Liberty, Ashmeads Kernel, Pitmaston Pineapple, and Hudson’s Golden Gem.Cleft graft one year old

Except for Wapanuka, the grapes never tasted as good here as they did at that experimental orchard. Is it because of terroir? Was it the setting that influenced my tastebuds? Anyway, they’ve been replaced by other “sticks” — Somerset Seedless, Glenora, and Vanessa — that now bear fruit in the rows with my older, established vines..

Murphy’s Law, Amendments

Although I have gardened for decades, I still consider myself a relative newbie to greenhouse gardening. Sure, I’ve dabbled in various greenhouses over the years but I’ve only experienced the intimate vagaries of my own greenhouse for the last 18 years. It took time for it to finally dawn on me that Murphy’s Law – “Anything that can go wrong, will go wrong” – also applies in the greenhouse. In retrospect, why wouldn’t it?Greenhouse, March 1st

  I’ve had my brushes with the law. For instance, one winter evening a few years ago when I went to pick some lettuce for a salad; methinks, “Hmmm, quite nippy in here.” But then, except from when sunlight is beaming through the plastic covering, it’s always nippy in there in winter. Salad greens, kale, chard, and celery thrive in those cool temperatures, which dip into the mid-30s before the propane heater kicks on. (The in-ground figs stay dormant and leafless.)

  Still, temperatures felt nippier than normal so I checked the thermometer to confirm and, yes, it was getting down to the high 20s. I then checked the propane heater; it ignored me as I twisted the dial on the thermostat clockwise.

  Right then and there, I proposed an amendment to Murphy’s Law: “Anything that can go wrong, will go wrong — at the worst possible time!” Temperatures the night before had plummeted below zero. No wonder a water line had burst that morning. I had assumed that frigid temperatures had made only that corner of the greenhouse too cold. Fortunately, after a lot of nail biting, the gas man and I determined that the pilot light had blown out in the heater. Most plants survived the cold.

  One event does not a Law make. Thinking back to another Murphy event, I remember an even more serious freeze in the greenhouse. One day everything looked verdant; the next day mush. (The gas company had forgotten to re-fill the propane tank.) After that event, I rigged up a backup electric heater, just in case temperatures dropped below freezing.

  Perhaps yet another Murphy’s Law Amendment is needed. On the night of a more recent freeze, the electric heater was, of course, hooked up. Except it wasn’t poised for warmth. The thermostat was directing it to wake up, but I had forgotten to flip the heater’s “on-off” switch to “on.” My bad.

  Live and learn: The sun is now setting, the mercury is now plummeting, but no fear of high winds blowing out the pilot light again. I subsequently upgraded the heater for a pilot light-less one. But when I go out to pick some lettuce, celery, and parsley, I will: Check propane heater, check electric heater, check that the water line is off. And remember to latch the door closed on my way out — really!

TOTIPOTENT — NOT WHAT IT SOUNDS LIKE

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 Cells Beget Plants, or Animals

   As I strode out to the garden today, the word “totipotency” was forefront in my mind. No, I wasn’t thinking of myself as “all powerful,” which is what totipotent (Latin totus=whole, potent=powerful) might seem to mean.
    Totipotency is the ability of any cell in an organism — you, me, my dog Sammy, my rose bush — to potentially give rise to any other kind of cell of that organism, or to a whole new organism, a clone of the original. Under the right conditions, you could put one of your skin cells in the right environment, and have those cells grow into new skin, toes, eyes — even a whole new you. Fortunately, nobody has yet figured out how to do that with a human.
    (What I wrote is not exactly true. Not every cell within an organism is totipotent. In organisms that reproduce sexually, egg and sperm cells — the germ cells — have only half their complement of genes, so these particular cells can’t be cloned to reproduce non-germ cells or whole organisms.)
    Back to the garden and totipotence . . . Using random plant parts to make whole new plants is nothing new to most gardeners. With stem cuttings, for example, you put a stem into a suitable environment, and it’s induced to grow roots at its base and new shoots, followed by flowers and, perhaps, fruits, above ground. With leaf cuttings, all these new parts spring from a mere leaf.
    Stems and leaves are more than just a few cells. More specialized, but still feasible, is cloning with just a few cells: so-called micropropagation or tissue culture. A few cells are removed, usually from a growing point, and then, under sterile conditions, put into a petri dish containing a medium to supply nutrients and a balance of plant growth hormones. The cells multiply without differentiation into anything special until they are transferred to another medium, this one with an altered balance of hormones, that induces cells to differentiate into leaves and roots. After a period of growth, the plantlets graduate to real soil.
    Micropropagation is a way to create many new, pest-free clones quickly and from a minimum of amount of mother plant.

Apolitical Graft

    My foray into “totipotencing” plants today required pretty much nothing more than pruning shears. I was cutting scion wood, which are stems for grafting onto growing plants. In this case, the growing plants — the rootstocks — provide roots to the clone; the completed plant, from the graft upwards, is the clone, in this case various varieties of pears.

Watersprouts on old apple tree

Watersprouts on old apple tree

    In the past, I’ve done a “Henry IVth” on pear trees whose fruits were not up to snuff, then grafted a more desirable scion on to the decapitated trees. Today’s scions are for grafting onto one-year-old pear seedlings, to make new pear trees. (Not that I need that many pear trees. The grafting will be done by participants at a couple of grafting workshops I’ll be holding this spring. Stay tuned to my website for when, where, and other details.)
    Grafts are most successful with young scions — one-year-old stems, those that grew last season. They come in various sizes, depending on their vigor; pencil-thick is about right. I cut them into foot-long lengths. Watersprouts, those vigorous, vertical branches often appearing in the upper parts of a tree, are good for scionwood, and most, anyway, should be removed.
 

Pear scions

Pear scions

  The odds for success are also increased if grafting takes place with dormant scions grafted on rootstocks that are either dormant or awakening. That’s why I collected scions today; they’re still dormant, but not for long, outdoors.
    I’ll keep those scions dormant with cold, in the refrigerator or my mudroom (north side of the house, tile floor over concrete).
    Drying out would spell death to the scions, as it would to any living plant or plant part. They need to be kept hydrated, but not in so moist an environment as to cause rotting. So I store them in a plastic bag, around which I wrap a moist towel, and then put the towel-wrapped bag into another plastic bag, well-sealed.

I Was Wrong About Arnold

    I was wrong. Back in December, I wrote, “My Arnold’s Promise witchhazel usually flowers in March. This year’s October flowering means no flowers this coming spring.” Well, it’s March 1st as I write this, and Arnold’s Promise is showered with strappy, yellow blossoms.

Witchhazel's winter flowers and remains of fall flowers

Witchhazel’s winter flowers and remains of fall flowers

    Evidently, not all flower buds slated to open this month opened prematurely, last October. Some did as they are supposed to do: waited. Why? Good question. Looking at the shrub, a location effect does not seem to come into play. Late winter blossoms seem randomly distributed rather than concentrated on older, younger, lower, higher, southern, or northern stems.
    With no explanation coming to mind (yet!), I’ll just relax and enjoy the unexpected show.

FLOWERS ALL WINTER

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Mine Aren’t Frilly

    And now, with a bow to my feminine side, a little something about African violets, houseplants that have traditionally been thought of as old lady’s flowers. Still, I’ll admit it, I like African violets. They offer so much for what little effort I make in growing them.
    Mainly, what they offer is flowers, and at a time — now and throughout fall and winter — when flowers are at a premium. I have only one variety, but if I was really into African violets, I could be choosing plants with white, pink, blue, or purple flowers, or blue with white picotee, or white blushed pink, or . . . any one of a number of flower colors and color combinations. And then there are varieties with ruffled, scalloped, quilted, or variegated leaves. And plants that range from few-inch wide miniatures to over a foot-wide large.
    My African violets are standard issue blue-flowered, flat-leafed, medium sized plants.
    As I said, I put little effort into growing them.
    If you study up on growing African violets, though, you’d think them very exacting in their requirements. For starters, they’re said to need special potting soil, well-drained but, with the addition of extra peat or sphagnum moss, consistently moist. They’re said to need bright light, preferably a north or west facing window, or fluorescent, but not too bright. Direct sun will allegedly burn their leaves. Avoid getting water on the leaves or it will leave a dark spot. Avoid getting water at the base of the plant (the crown) or it will rot. Avoid overwatering. Avoid underwatering. Oh, and I almost forgot to mention: Avoid cold water.watering African Violet
    Moving on to the air around the plants . . . avoid chilling the plants, moving them away from cold windows at night or stuffing some newspaper between the plants and the window. But also don’t keep the plants too warm.  Also, ramp up the humidity by growing them in the basement or setting them above trays filled with pebbles and water.
    Whew! That’s effort. I don’t do any of that. I use the same potting soil for African violets as for all my other plants (except succulents), from tomato seedlings to fig trees to bonsai Ficus. My plants sit happily in south and west windows, some in a cold room with nothing to stop the flow of cold from the the glass. My watering is whimsical, leaving them sometimes sitting in too much water and other times in bone-dry soil. I pay no special attention to water temperature or to whether or not water gets on the leaves.
    My African violets are growing and flowering just fine.

Leaves into Plants

    Perhaps my African violets grow too well because every a couple of years or so they get so overgrown that they’re spilling up and out of their pots. Then it’s time for one of the coolest things about growing them, and that’s propagating them.
 Rooting African violet leaves   I do so by cuttings, but not by the usual stem cuttings. African violets hardly have a stem; the crown, or whorl of leaves, is a foreshortening stem, too short for a stem cutting. I propagate them with leaf cuttings, typically taken in spring. Nothing complicated here: Just pull off some leaves and poke the leaf stalks (petioles) into a rooting mix of potting soil or equal parts peat and perlite. Water thoroughly, make a plastic tent or use an upturned, clear jar to maintain humidity, and move the whole setup to a bright location (definitely not full sun this time, or plants might cook!).

African violet leaves, rooted

African violet leaves, rooted

    All that’s needed is patience. In a few weeks, from the bases of the leaf stalks appear new shoots, on their way to becoming whole, new plants. Fascinating.

Leaves into Plants, Another Way

    A few years back I sowed dust-like seeds from a begonia plant. The seedlings matured into a few plants that were mounds of green, dripping all summer long with fire-engine red blossoms. I cloned the plants with stem cuttings, which took up a lot of space and were slow to root. So, I’m thinking, why not leaf cuttings for the begonias also, this spring?
    Begonias can be multiplied by cutting the fleshier parts of leaves into triangular sections, each with a major vein, and sticking each triangle upright in a rooting mix. Or, another approach is to cut across the large veins on the undersurface of a begonia leaf, then lay the whole leaf on the rooting mix, pinning it down to maintain contact with the mix. In either case, with moisture, a clear tent, bright light, etc., roots and new plants develop. Again, fascinating.

Any Cell Can Do It

    The reason that I or you can make a whole new plant from part of a plant is because of totipotence. This ten dollar word tells that any cell in a plant, except reproductive (egg and sperm) cells, houses identical genetic information, and that information can give rise to any other part of a plant, even to a whole new plant. It’s up to the skilled gardener to provide the conditions that prompt a plant part to develop into a whole new plant.