Gardening – Page 13

Future Hopes

February 27, 2019/4 Comments/in Fruit, Gardening, Planning/by Lee Reich

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 graft Grape 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!

Late Winter Sap, Pruning, and Planting

February 20, 2019/12 Comments/in Gardening, Pruning, Vegetables/by Lee Reich

The Sap is Flowing

In past years, now is when we would always hope to make enough maple syrup to last until the following year at about this time. Maple syrup consumption has dropped dramatically, leaving me with quite a backlog of the stuff. So trees haven’t been tapped for the past few years. Tapping a maple tree

Not that we ever made that much maple syrup. Four tapped trees always produced sufficient sap for a year’s worth of syrup. It had to, because that’s how many spiles (taps) and buckets we own.

Our operation was nothing like what I came upon a couple of weeks ago cross-country skiing in the woods of northern Vermont. All of a sudden tubes had appeared in the pristine, white wilderness. Tubes everywhere! Baby blue plastic tubes, black plastic tubes, interlocking connectors, everything neatly wired into position at chest height and thoughtfully out of the way of any skiers enjoying the woods.

Processing the sap here at home is done quite differently from those commercial operations. Our low-tech approach was to merely add each day’s “catch” from the four buckets to a big stock pot sitting on the woodstove. The woodstove is stoked pretty much continuously this time of year, so the sap was always evaporating, with the added bonus of humidifying the house. Boiling maple sap

I see a few eyebrows going up. Sticky walls and ceiling are what comes to some minds upon the mention of cooking down maple sap indoors. Well, that’s usually myth. Sticky walls and ceiling only result when the sap is in an active boil and bubbles bursting on the surface of the liquid sent little droplets of sugar water into the air and onto walls and ceilings. But until the final stage of our sap-making, the sap was just slowly evaporating. The vapor given off by slowly evaporating, simmering, or boiling a solution of any sugar and water is nothing more than water vapor. That’s why the maple sugar becomes concentrated in the remaining liquid.

In those final stages of concentration, with much reduced liquid volume, the liquid can indeed reach an active boil. The pot of liquid announces that it’s nearing that stage by starting to gurgle like a baby, at which point it needs to be watched closely, mostly so that the syrup doesn’t get too concentrated or burn. The finish point is when the temperature of the liquid reaches about 219 degrees F.

Another Maple, Not So Good

Someone contacted me to say that, “The squirrels were chewing on Norway maple tree last week and sap was seen dripping down,” then went on to ask if that meant it was too late to prune. Perhaps the squirrels were enjoying some of the sweet sap. Yes, you can tap and boil into syrup the sap of all kinds of maples; I’ve tapped and made syrup from silver maple, red maple, boxelder, and, of course, sugar maple.

Getting back the pruning… It’s not at all too late. It’s fine to “dormant” prune any plants up until the time when they unfurl their leaves in spring.

Another good question might be: Why not just cut the Norway maple down to the ground? The trees are invasive and displacing our sugar maples, they have poor fall color, and they create lugubrious shade beneath which grass and much else can’t grow. Mostly, people keep these trees because they are already in place and full grown.

Pea Planting, Almost

Despite snow covering the ground on the ground, I’m still planning to scratch open a furrow and plant peas – the first outdoor planting of the season – on April 1^st.

Given the white blanket, which may not be around by the time you read these words, some people might think me crazed for planting peas so soon. Then again, those people who insist on getting their peas in the ground before St. Patrick’s Day might think I’m dragging my heals. Winter scene, N garden

Here are the facts: Peas grow best at cool temperatures, making early sowing a must. The seeds will sprout whenever the soil temperature is above 40 degrees F. But St. Patrick’s Day can’t be the universally best time to sow peas because different places experience different climates on that date. It’s probably too late in Florida, too early in Maine, and just right in Ireland.

So call me a fool if you like, but I’m still planning on an April Fools Day planting for my peas. I’ll wait a few more days if the ground is frozen or covered with snow. Just a few days though, because things move quickly this time of year. Winter scene, looking south

Cold Rules

January 30, 2019/9 Comments/in Gardening, Planning, Soil/by Lee Reich

Water Freezes. Why Don’t Plants?

(The following is adapted from my book, The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden, available wherever fine books are sold, and my website.)

Not being able to don gloves and a scarf, or shiver, to keep warm, it’s a wonder that trees and shrubs don’t freeze to death from winter cold. They can’t stomp their limbs or do jumping jacks to get their sap moving and warm up. The sap has no warmth anyway. Trellis and snow

Sometimes, of course, plants do succumb to winter cold. But usually that happens to garden and landscape plants pushed to their cold limits, not to native plants in their natural habitats or to well adapted exotic plants.

Think about it: water freezes at 32 degrees Fahrenheit—not a particularly cold temperature for a winter night—and plants contain an abundance of water. Water is unique among liquids in that it expands when it freezes, so you can imagine the havoc that could be wreaked as water-filled plant cells freeze and burst. Yet plants that must stand tall all winter do, of course, deal with frigid weather.

A Helping Hand for Herbaceous Plants

Herbaceous perennials (non-woody plants) opt for the easiest survival route.Their roots are perennial but their tops die back to the ground each year. Anticipate cold weather, these plants start pumping reserve nutrients to their roots in late summer. That’s why asparagus, cone flowers, delphiniums, and peonies are reduced, in autumn, to nothing more than a few dry stalks. Mulched garden bed

What’s left of these plants spends a mild winter underground. Five feet down, the earth’s temperature hovers around a relatively balmy 50 degrees Fahrenheit.

Practical Rule #1: A thick blanket of some fluffy, organic material—leaves, straw, or wood chips, for example—further limits cold penetration.

Also for Woody Creepers

Low-growing, woody plants have it almost as good, with their stems shielded from the full brunt of cold winter winds. If Nature decides to throw down a powdery, white insulating blanket, so much the better: those leaves and low stems are protected even more. Lingonberry under snow

Practical Rule #2: In case Mother Nature is distracted with other activities, I provide my own low blanket for low-growing, woody or evergreen perennials—again, that fluffy cover of straw, leaves, or wood chips. Waiting to cover these plants until the weather turns relatively cold (soil frozen an inch deep is a good rule of thumb) lets plants acclimate to cold, and their stems and leaves have no chance of rotting beneath mulch that is still moist and too warm.

Tricks and Tips for Trees and Large Shrubs

What about trees and shrubs whose stems are fully exposed. One way they protect themselves from freezing is by shedding those parts most likely to freeze—their leaves. Blueberries and snow

Which introduces Practical Rule #3: I help plants along with their leaf shedding by letting plants naturally slow down and begin to reallocate their energy resources beginning in late summer. No water, fertilizer, or pruning at that time.

Of course, their stems still have to stand up and face the cold. Their living cells are filled with water. If this water freezes, the cells either dehydrate or suffer physical damage from ice crystals.

Water, whether in a plant cell or a glass, does not necessarily freeze as soon as the temperature drops below 32 degrees Fahrenheit. To freeze, water molecules need something to group around to form ice crystals, a so-called nucleating agent. Otherwise it “supercools,” remaining liquid down to about minus 40 degrees Fahrenheit, at which point ice forms whether or not a nucleating agent is present.

All sorts of things can serve as nucleating agents—bacteria, for instance—so plants may not be protected all the way down to minus 40 degrees Fahrenheit by having their water supercool. But winter temperatures don’t plummet that low everywhere, so just a bit of supercooling may be all a plant needs to survive winter cold.

Another trick, effective well below that minimum supercooling temperature, is for a plant to gradually move water out of its cells into spaces between the cells. As temperatures drop, ice crystals outside plant cells grow with the water they draw out of the cells; plants then are threatened by dehydration than by freezing. Plants toughest to cold are those that are best at reabsorbing the water outside their cells when temperatures warm. Kiwivines covered with ice

One other mechanism at work “freezing point depression,” which is why antifreeze keeps the water in your car radiator from freezing. Dissolving anything in water lowers the freezing point, more so the more that’s dissolved. As liquid in plant cells lose water, remaining water becomes more and more concentrated in sugars and minerals, its freezing point keeps falling.

Plants actively prepare for cold, with cell walls increasingly strong and and permeable. Light supplies needed energy for all this, making Practical Rule #4 to make sure to site and prune plants for adequate light.

Unfortunately, all this fiddling with a plant to help it through winter palls in the face of genetics. The very most that I can do to help plants face winter is to plant those that naturally tolerate the coldest temperatures winter is apt to serve up.

Gardening by the Book

January 15, 2019/6 Comments/in Gardening/by Lee Reich

An outdoor temperature of 8.2 degrees Fahrenheit this morning highlighted what a great time winter is for NOT gardening, but for reading about gardening. A lot of gardening books, new and old, end up on my bookshelves, and I’d like to note a few favorites new to my shelves last year.

(Disclaimer: I had a new book published last year, The Ever Curious Gardener — available here. I like the book very much.)

For anyone serious about vegetable growing, Eliot Coleman, gardener extraordinaire, is the author to seek out. The Winter Harvest Handbook builds on his The New Organic Grower (recently re-issued to celebrate its 30th year since publication!) and Four Season Harvest, delving into innovative techniques for growing vegetables more efficiently and year ‘round, with minimum heat inputs even in northern climates.

The “aha” moment for me in reading Eliot’s method’s for year ‘round harvests was that sunlight, even this far north, is not limiting plant growth in winter. New York City and Madrid are at the same latitude! Mediterranean gardeners don’t abandon their vegetable gardens in winter; they just change plants, growing vegetables, such as spinach, lettuce, cabbage, and radish, that tolerate and enjoy cold weather. What we need on this – the cold side – of the big pond are ways to contain the earth’s heat and/or to provide heat efficiently to keep plants alive and growing. Read the book.

The title of the book Tricks with Trees, by Ivan Hicks and Richard Rosenfeld, doesn’t do justice to the neat things shown that people have done, and you could do, with trees. How about a tree trained as a chair, a living chair? Don’t expect to move such a chair anywhere because it’s rooted in the ground. One of my other favorites in the book is the “cloud seat.” (Use your imagination and you might guess what this is.)

People love the idea of meadows, perhaps because meadows seem low maintenance, perhaps because humans originated in the savannahs of Africa. Meadows have become very popular over the last few decades, and lots has been written about them. (I even have a meadow section in my book Weedless Gardening.) The American Meadow Garden, by John Greenlee, offers all you need to know and to grow a meadow. Saxon Holt’s photographs were so inspiring I contemplated turning my one-acre meadow into, well, more of a meadow. After seeing the photograph on page 41, I want shooting stars, a milkweed relative, in my meadow, which gets nothing much more than a yearly mowing.

Greenlee’s book does keep you grounded with plenty of information about the plants, about preparing the ground, and about maintenance, especially weed control. Maintenance? Weed control? Yes, a meadow, depending on your aspirations, may need both. My only beef with this book is that Greenlee makes no mention of mowing with a scythe, a most pleasant and very efficient tool for meadow maintenance.

Last, but certainly not least, is Science and the Glasshouse by William Lawrence. If the title sounds a bit old-fashioned, it’s because the book is old-fashioned; it was written in 1950. I visited Eliot Coleman this past summer and sometime during the visit we were lobbing titles of our favorite books back and forth. He threw me this one after I had lobbed to him Intensive Gardening, by Rosa O’Brien, also 1950 vintage and one of my favorite gardening books of all time (and one he had suggested to me back in 1973).

Back to Science and the Glasshouse, which I ordered asap, actually asaicgo (as soon as I could get online). My favorite thing about this book is that it challenges many commonly held notions by testing them scientifically. Mr. Lawrence, then head of the Garden Department of the acclaimed John Innes Horticultural Institute in Britain, subjected to scientific inquiry such beliefs as: cold soil is harmful to potted seedlings (it is not); crowding potted plants decreases growth of individual plants (sometimes); size matters, in pots for transplants (yes), and so on.

The second half of the book is devoted to the “glasshouse,” which greenhouses literally were back then. Mostly, his testing showed that plants in greenhouses did not always get all the light they should, not because of a lackadaisical old sol but because of dirty glass, poor orientation, and other things we can control. Which brings us around full circle back to Eliot Coleman’s capitalizing on winter sunlight.

Some Dirt Under the Fingernails

Okay, I am, in fact, doing a little gardening. I went down to the basement and brought 2 amaryllis plants upstairs to get them started growing for blossoms in February(?).

A Wizening Little Tree

January 9, 2019/4 Comments/in Gardening/by Lee Reich

Now, in its tenth year, my weeping fig is just waking up. (This plant is not one of my edible figs weeping from sadness, but a species of fig — Ficus benjamina — with naturally drooping branches.) As a tropical tree, its sleep was not natural, but induced, by me.

In its native habitat in the tropics, weeping fig grows to become a very large tree that rivals, in size, our maples. The effect is all the more dramatic due to thin aerial roots that drip from the branches, eventually fusing to create a massive, striated trunk. Because the tree tolerates low humidity, it’s often grown as a houseplant. Growth is rapid but with regular pruning the plant can be restrained below ceiling height.

At ten years old, my weeping fig is about four inches tall with a trunk about 5/8 inch in diameter and no aerial roots. Four inches was about the height of the plant when I purchased it in the houseplant section of a local lumberyard. Actually, four of these plants were growing in a 4 inch square pot. I separated them and potted one up with the idea of creating a bonsai.

The bonsai has been a success. Each year the trunk and stems have thickened to create the wizened appearance of a venerable old tree, in miniature. The soil beneath the spreading (if only 3 inch) limbs is soft with moss which has crept slowly up the lower portion of the trunk.

To Sleep, My Little Tree

Even after ten years the plant is in the same pot in which I originally planted it, a 4 by 6 inch bonsai tray only about an inch deep. Biannual repotting and pruning has been necessary to keep the stems and roots to size, and to refresh the potting soil to provide nutrients and room for roots to run (albeit very little room for a tree with such size potential).

Back to my tree’s sleep: A few weeks ago, the sun dipping lower in the sky for a shorter time each day seemed to me like a good time to give the plant a rest, which it surely would be taking following my operation.

I began with the roots. After tipping the plant out of its pot, I used a fork to tease soil away from the bottom of the root ball. Roots left dangling down in mid air as I held the plant aloft were easy to trim back. I was careful to leave the top portion of the roots and soil undisturbed in order to keep the mossy blanket intact.

With enough fresh potting soil added to the pot so the tree (despite its size, I think I can call it a “tree”) would sit at the same height in the pot as previous to pruning, the tree was ready to return to its home. I firmed it in place.

Next, I turned to the above ground portions of the plant, beginning by pruning stems so the tree would look in proportion to the size of its container and to maintain the increasingly rugged look of a tree, in miniature, beyond its actual years.

Finally, I clipped each and every leaf from the plant. This shocks the plant to sleep and reduces water loss, important for a plant from which a fair share of its roots have been sheared off. Clipping off leaves also induces more diminutive growth in the next flush of leaves, so they are more in proportion to the size of the whole plant.

After a thorough watering, the tree was back in its sunny window. And there it sat, leafless, until a few days ago, when small, new leaves emerged.

Pruning Moves Outdoors, Prematurely Perhaps

Pruning and repotting the bonsai wasn’t enough gardening for me. A couple of sunny days couldn’t help but drive me outdoors. A pile of wood chip mulch delivered a few months ago beckoned me; I spread it in the paths between my vegetable beds, a pre-emptive move to smother next season’s weeds.

I don’t usually prune this time of year (The Pruning Book, by me, recommends against it!), but couldn’t restrain myself. I started with the gooseberries and currants, both of which are super cold hardy plants so are unlikely to suffer any damage from pruning now. Plus, they start growth very early in spring.

Any of this gardening could be postponed until late winter or early spring. But why wait?

Dry, Wet, Bad, Good?

December 26, 2018/10 Comments/in Fruit, Gardening, Pests, Soil, Vegetables/by Lee Reich

Some Bad

Wow! What a gardening year this has been. Looking back on 2018, it’s been the oddest year ever in terms of weather, insects, and disease.

After starting off the season parched, seemingly ready to go into drought, the weather in July did an about face. The rains began. Average precipitation here in the Northeast is about 4 inches per month. July ended up with about 6 inches, August saw 5 inches, September 8 inches(!), October 5 inches, and November 8 inches(!!).

All that rainfall brought humidity, which might have been responsible for my celeriac plants hardly growing, then rotting.

Celeriac, early in the growing season, before the rains

(Perhaps not, because this was my third growing season of failure with celeriac.) I’m taking this as a celeriac challenge. Perhaps next year I’ll try them in a large tub where I can have more control over soil composition and moisture.

The humidity also had too many figs morph into fuzzy, gray balls as they softened and sweetened.

Tomatoes this year tasted very good, as usual, but yield was way down and too many showed some rotting areas. (In my experience, growing tomatoes under variable soil and weather at various locations around the country, their flavor is mostly a matter of genetics; a good variety tastes good everywhere.) Particularly irking was anthracnose disease, which often isn’t noticeable when fruits are harvested, but quickly shows up as round, sunken areas.

Onions suffered this season. Mostly they were stunted, and I’m not sure why.

Zucchini was a bust because the plants petered out from powdery mildew and vine borers just after midsummer. I usually circumvent these common problems with multiple plantings, starting new zucchini plants in early summer to replace the decrepit ones. I forgot to replant this summer (probably because I don’t like zucchini all that much anyway).

Medlar is an uncommon, very old-fashioned fruit that I’ve grown for many years. Although it’s gotten a bad rap for it’s ugly — to some people — appearance, the flavor is delicious, the soft flesh creamy smooth like apple butter with a similar flavor livened with vinous overtones. Medlar fruit in hand Usually the plant is pest-free but a few years ago something, perhaps a fungus, perhaps an insect, started attacking it, leaving the flesh dry and crumbly. I have yet to identify the culprit so that appropriate action can be taken. Medlar pest damage

Some Good

Not that this past growing season was bad. I won the battle against soft scale insects (mealybugs) on my greenhouse figs, although their ecological niche was filled by just-as-bad armored scale insects. A close eye and an occasional spray of Neem oil kept flea beetles at bay from eggplants.

A couple of the same Neem sprays beginning in mid-September may have kept a new pest in the area, Allium leafminer (ALM, Phytomyza gymnostoma) at bay. Last year each of my near perfect-looking leeks revealed a rotted stalk as I lifted them out of the ground.

Allium leafminer

Then again, I did plant this past season’s leeks far from where the previous season’s leeks grew. Then again, the ALM flies can fly. Then again, maybe they weren’t here this year; perhaps the weather was not to their liking.

This past season’s leeks

There was also no sign this past season of the white flies that decimated my kale the previous season.

Spotted wing drosophila (SWD), a species of fruit fly that has invaded the country relatively recently, did mostly ruin autumn ripening yellow and black raspberries. But little damage was suffered by my favorite (and perennially most successful) fruit, blueberries, probably thanks to some experimental traps developed by Peter Jentsch of Cornell University.

SWD trap

Peppers were even more of a success than usual, mostly due to my staking the plants. The only fault of Sweet Italia, my favorite variety for its early ripening, for its flavor, and for its good yields, is that the fruit-laden plants flop over under their own weight. Eventually, the small bamboo stakes I used proved only partially adequate; next year they’ll get the stakes they deserve.

I treated a few beds in spring to a relatively new method for weed control: tarping. Laying a sunlight-blocking tarp down on the ground for a couple of weeks or more in spring warms the soil beneath, stimulating germination of any weed seeds lurking there. The sprouting seeds are disappointed by the incessant darkness. They die. Timing, temperature, sunlight, and duration of tarping all play a role in this techniques effectiveness.

(Tarping is very different from using black plastic mulches. The latter are kept in place all season long, with garden plants growing in holes or slits in the plastic. Soil beneath the plastic can suffer from lack of air or, if not drip irrigated, lack of water. Also, the tarp — mine came from www.billboardtarps.com — can be folded up and re-used for many seasons.)

And finally, we were happy to find some assassin bugs and anchor stink bugs, Stiretrus anchorago, in the garden. Both are beneficial insects — yes even that particular stink bug.

Immature beneficial stink bug

Good Overall

All in all, it was a good season — as always. The secret is to grow many different kinds of plants. No season, no matter what the weather or pests, has ever been bad for all plants.

Mystery Solved, and Frigid Dealings

December 19, 2018/5 Comments/in Gardening, Vegetables/by Lee Reich

Mystery Plant: No longer a Mystery

Last week I mentioned my brother’s mystery shrub, which he wanted to prune back heavily. I told him it was okay to do so even though I — and a number of experts I consulted — could not identify the plant.

(Drum roll . . .) The plant has finally been identified, by Mark Brand of the University of Connecticut, as Wilson rhododendron, Rhododendron x laetevirens. I had narrowed it down to R. carolinianum, which is one of the parents of this hybrid, the other being R. ferrigineum.

Wilson rhododendron flower bud

My brother’s not noticing flowers on this rhododendron is understandable. It’s a super cold hardy but sparse bloomer that’s grown mostly for its foliage; the pointy leaves don’t droop or curl, but remain perky, even in frigid weather.

Now I can sleep nights.

It was Cold Outside!

Talk about frigid weather: I was surprised at how cold it was on the farmden during my Thanksgiving visit to my bro’ in Rhode Island. The night of Friday, November 23rd, New Paltz weather reported a low of 7° F. Brrrrr. As I’ve mentioned before, I live in a valley. Cold air, which is heavier than warm air, sinks into low spots, bringing the temperature right out in my garden even lower, down to 3° F.

(I knew this even when in Rhode Island, thanks to Sensorpush, a nifty device that transmits minute by minute temperature and humidity conditions to my cell phone from wherever the device is located.)

It’s all about microclimates, which are localized differences from the general climate due to such influences as heat-absorbing masonry walls and paths, which keep temperatures warmer in winter. Or nearby bodies of water, which keep temperatures warmer in winter and cooler in summer. Or differences in elevation, lowering the temperature 6°F for every 1000 feet of elevation, and low lying areas.

Lower temperatures with elevation might seem contradictory to the locally colder temperatures in my garden that night. These colder temperatures occur only when still windless air and a clear sky let any heat the ground has accumulated by day re-radiate back to the heavens. A cloudy night or tree cover would reflect that re-radiated heat back downwards, preventing the cooling. With radiative cooling, air near the ground is coldest, and and warmer air hovers higher up.

Microclimate Adjustment=Fresh Salad Greens

As a gardener, I can play around with microclimate and have it work for me, as evidenced from the fresh endive, winter radishes, lettuce, and turnips just harvested from right out in the garden.

Preparation for that harvest began in late summer with spreading compost in the bed and the sowing of endive seeds. I planted turnip, lettuce, and winter radish seeds in the bed in September.

Back in early October I spaced metal hoops 4 feet apart along the bed, each one spanning from one side to the other of the bed. Later on in October, I covered the hoops with a length of clear plastic, slitted row cover creating a tunnel over the bed. The slits keep the interior of this mini-greenhouse from overheating. Tunnel, clear plastic, vented, closeup

Moving into November, temperatures gradually cooled but still not enough to threaten the covered plants. Between the plants natural cold hardiness and the cover, I figured they were fine into the low 20s. (For more on microclimates and their manipulation, see my new book The Ever Curious Gardener.)

Short days and low hanging sun, coupled with cool temperatures, were not providing conditions for plant growth. But the plants were, by then, fully grown, so no more growth was needed. At that point I laid a cloth cover over the tunnel to keep out further depths of cold. Light became immaterial; I just wanted the plants alive and fresh. Tunnel with covers, Dec, endive revealed

And so they have remained, even after temperatures plummeted to 3°.

Not only are the plants alive and fresh. Cold temperatures have brought out the best in their flavor. The veggies are crisp, sweet, and tangy. Turnip from tunnel

Read the Book, Bro’

December 13, 2018/12 Comments/in Design, Gardening, Pruning/by Lee Reich

To Prune or Not To Prune, That is the . . .

So I visited my brother and his family for Thanksgiving. As usual, we walked around his yard to look at his plantings. As usual, he asked my advice, this time about pruning. (As usual, he didn’t want to consult a copy of my book, The Pruning Book, which I had given him a few years ago. “Why read it, when I can just ask you?!” he says.) My brother's mystery shrub

He was considering taking blades to a row of handsome, evergreen shrubs along the front of his house. Over the years, the lengthening branches had sprawled out to encroach upon the bordering lawn, in some places leaving exposed bare stems. He questioned whether new growth would sprout if he lopped all those sprawling stems back to near the roots.

But what was the plant? I had an excuse, admittedly rather lame, for not knowing it: I learned all my ornamentals in Wisconsin where not many broadleaf evergreens are hardy. No matter. Sometimes you can figure out how to prune an unknown plant by just studying its growth habit.

Many evergreens, including most pines, Douglas firs, rosemary, and some rhododendrons, will not sprout new growth if cut back to bare old wood. (At the other extreme are boxwoods and yews, which sprout all over the place no matter how they are cut back.)

I suggested going ahead with drastic pruning of the unknown shrub. My confidence came from seeing many young sprouts emerging from the old stems right near where they emerged from the ground and then bent over from their own weight. Hormones within plants promote sprouting of vigorous, new shoots near the high point of a stem wherever it bends over. Pruning a stem back likewise promotes sprouting right near the cut.

I Pass Judgement

Looking across the front path, bro’ next asked me how I liked the pruning job he’d done on his rhododendrons. Hmmm, pretty good. My brother's pruned rhododendron

As often happens with rhododendrons, they are planted near a home and then too often grow so large as to swallow up windows, even the whole side of the home. His had done so, and he had pruned stems back to the height he wanted.

Two problems with this pruning. First, as noted above, when a stem is pruned back, most regrowth, and the most vigorous regrowth, occurs just below the cut. So although he cut the plant down to size, he should expect it to start growing back up to its previous size quickly.

The other problem with this pruning is that it leaves the plant looking butchered, large wounds gaping out atop thick stems whose upward mobility has been abruptly stopped. The best pruning jobs are ones where a plant looks nice without looking as if it has even been pruned.

My approach would have been to make a few cuts of the largest stems down in the interior of the shrub, where the stems originated. The largest stems would also be the tallest ones, so such cuts would be effective in lowering the plant. If too many need removal at once, the operation could be spread over 2 or 3 years. Then the pruning cuts would hardly be noticed, and letting light down low among the stems would promote healthy new growth starting low.

With all that said, my brother’s rhodies didn’t look too bad — and he has the opportunity over the next year or two to make my suggested cuts. Lucky for him, his rhodie was not one of the few that are reluctant to make new sprouts in lopped back older wood.

Moving On

Once I get started pruning, it’s sometimes hard to stop. As I looked at his yew shrubs along another part of his house, I suggested paring down the size of that rectangular block of greenery. My brother's yew hedge

Pruning yew is easy. Since it resprouts up and down stems no matter how severely it’s cut, you can do almost anything to it. His large hedge could even be cut down to stumps to begin life anew — quickly, because it has an established root system.

Most important when reducing the size of the hedge, no matter how it’s cut, is to reduce the whole hedge to a size smaller than finally desired. When maintenance trimming a shrub with hedge shears, trimming is generally further out from where the newest shoots began their growth for the season. That’s why hedges grow larger over time, unless they’re periodically lopped back more drastically, which doesn’t leave them looking that good until those cuts are covered by new growth.

And the Mystery Shrub is . . . ?

I don’t feel so at a loss at not being able to identify my brother’s mystery shrub: I sent a photo of it to a few experts, none of whom could identify it.

GREAT GIFT IDEAS

December 10, 2018/2 Comments/in Gardening/by Lee Reich

Gardening books, of course.

Uncommon Fruits for Every Garden

Landscaping With Fruit Grow Fruit Naturally

Of Crocs and Glads

December 5, 2018/9 Comments/in Flowers, Gardening/by Lee Reich

No-Dig Crocs

Plants grow and multiply, which sometimes causes trouble. Such trouble was highlighted this week as I was digging up my crocosmia bulbs.

Crocosmia up close Backpedaling perhaps 20 years, you would have found me ordering crocosmia bulbs from a mail-order catalog. I’d seen the plants blooming in a friend’s garden in New Jersey and marveled at the graceful flower stems that arched up and out from clumps of sword-shaped leaves. Lined up near the ends of each flower stalk were pairs of tubular, hot scarlet blossoms.

Crocosmia isn’t supposed to be cold-hardy outdoors where winter temperatures drop below minus 10 degrees F. (hardiness zone 5), so the first couple of autumns, as instructed, I dug up the bulbs for winter storage. Each spring following, the plants would get off to a slow start, finally blooming late in the season or not at all.

In disappointment or laziness, I stopped digging the bulbs up each fall. I was surprised to see them appear in spring anyway. Not only did they appear in spring; they had some real oomph, growing almost as luxuriantly as the ones in my friend’s garden. To make matters better, they started blooming earlier, in July, and in great profusion, and they have done so reliably year after year with no help at all from me. Crocosmia and daphne

The crocosmias also multiplied, and they did so with such enthusiasm that there became just too many of them at the original location. So I started digging. And I uncovered bulb after bulb after bulb, ready to bloom and multiply next year. Now I have to decide what to do with all those bulbs. Plant them? Give them away? Compost them? I would have never thought I could have had too many crocosmias.

Glads Won’t Die

Does anybody around here still dig up their gladiolas each fall? I don’t, but to no avail. Left outside, they still survive every winter. Yuk. (Gladiolus “bulbs” are, like crocosmia “bulbs,” actually bulb like structured called “corms.”)

I don’t like gladiolas. Perhaps it’s because they are the most popular flower for funerals.

At any rate, I did, for some reason, plant some glads over 30 years go, glads whose beautiful salmon, pink color I subsequently felt was wasted on glad flowers. The nice color couldn’t outweigh the funereal associations, so after a couple of years of digging them up for storage each fall, I decided to sacrifice them to winter cold. Gladiolus

Unfortunately, they reappeared each year, and have continued to do so annually. I have to chuckle whenever I read instructions such as: “Corms should be dug after foliage has matured and started turning brown. Lift corms carefully with a spade or spading fork, taking care not to cut into the corm. Cut the tops off 1inch above the corm and dry for 2 to 4 weeks in a warm location (70-80 degrees Fahrenheit) with good air circulation. Remove the old corm which is beneath the new corm. Discard any rotted or damaged corms. Cut stems back to within an eighth of an inch of the corm. Place the corms in an onion sack or old nylon panty hose. Hang from a wall or ceiling. Ideal storage temperatures are between 35 and 40 degrees Fahrenheit.”

Hah! Doing nothing at all has, unfortunately, worked fine for me. At least the gladiolas haven’t multiplied as fast as the crocosmias.

Cold Air, Not So Cold Soil

The whole concept of winter hardiness for a plant only whose roots (or corms, in the case of crocosmia and gladiola) need to survive winter is hazy. After all, three feet down in the soil almost everywhere, temperatures hover around 50 degrees Fahrenheit.

Lay some mulch on top of any soil and penetration of winter cold can’t reach as deeply as through bare soil or lawn. Bare soil doesn’t peek out anywhere in my garden. Whatever is not lawn has been mulched year after year for many years with leaves, wood chips, sawdust, compost, hay, or whatever other organic materials I can get my hands on. (No, my garden isn’t three feet higher than it was when I started because those organic mulches decompose, enriching the soil as they do so.)

Nonetheless, the ground that the crocosmias and glads call home is well-insulated from winter cold. Warmer winters for the past few years have also helped these “nonhardy” bulbs survive outdoors, especially the less cold-hardy gladiolus.