Gardening by the Book

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.)

The Ever Curious Gardener

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

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.

Bonsai fig

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).

Bonsai at one-year old
Bonsai at one-year old

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.

Root pruning bonsai

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.

Bonsai, fig, clipping leaves, '18

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.

Bonsai, fig, '18, new leaves

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?

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 in new home

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 handUsually 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

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.

Nice leeks

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

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

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

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

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’

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.Close up of mystery shrub stems

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

Gardening books, of course.
The Pruning BookThe Ever Curious Gardener

 

 

 

 

Uncommon Fruits for Every Garden

 

Landscaping With FruitGrow Fruit Naturally

Of Crocs and Glads

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 closeBackpedaling 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.

Of Worms and Leaves, Here and Beyond

Unreiking is Good Exercise

For the past few days I’ve been engaged in the esoteric exercise of unreiking. Basically, this involves lifting heavy (or sometimes light) sacks, slitting them with a knife, and then moving my arms back and forth over the spilled contents. Okay, okay, the “sacks” are plastic bags, their contents are autumn leaves, and I’m holding a pitchfork in my hands as I spread out the spilled leaves.

Leaf bags with pawpaws

Sammy is looking forward to this leafy mattress

(Unreiking is the reverse of another esoteric exercise, reiking, whereby  . . .  well, leaves are raked up into plastic bags.)

Some people have too many leaves or otherwise don’t want them around. I have too few leaves and have use for them. By unreiking, the leaves get spread beneath my berry bushes, grape vines, and pear trees. These leaves feed bacteria, fungi, and other soil microbes, which slowly rot down the leaves to enrich the ground with nutrients and add organic matter that helps the soil hold both moisture and air.

Sammy also likes the mulch

Ahhhhhh

After doing this autumn after autumn for many years, the ground beneath these plants is as good as any agriculture soil in the world.

A Gardener’s, Farmdener’s, and Farmer’s Friend, Reconsidered

Our forest soils are similarly enriched, though to a lesser degree, with each autumn’s leaf drop. But change is under way, and the culprit is the earthworm.

Backtrack to about 12,000 years ago; that’s when the last glacier receded from the northern parts of the U.S. The glacier froze, compacted, churned and moved soil everywhere north of New Jersey, the upper parts of Pennsylvania, Ohio, Indiana, and Illinois, and parts of Wisconsin and South Dakota. Most of North Dakota was also enveloped by the the glacier, as well as, moving further west, the northern parts of the northern most states. In so doing, it killed off any native earthworms.

The still existing native earthworms to the south could have migrated back up here, but they move very slowly. Earthworms’ top speed is estimated at less than 6 yards per year.

Here, north of that line of glaciation, you and I do see earthworms in our soil. They’re not native; they arrived here nestled within pots of soil and organic debris, and as discarded soil ballast in ships, beginning in about the 17th century, with European colonists. And they liked it here.

More recently, those European immigrants — the worms, that is — were joined by worms from Asia.

Both species of non-native earthworms continue to spread in the soil of potted plants, in compost and leaf mulches, in home composting kits, and in discarded fishing bait (“nightcrawlers”).

Problem is that a few species of these non-native earthworms are very good a decomposing the leafy mulch that blankets forest floors. The blueberry, mountain laurel, rhododendron and other shrubs and ground covers in our forests thrive in that leafy mulch. The action of these non-native earthworms threatens to change the character of our forests.

Eek, A Snake Worm!

A number of years ago, my friend Sandy told me of strange happenings in her garden, of the abundance of worms and worm castings to the extent that the soil became so loose that her plants were flopping over. I pooh-poohed this report until a bit of research revealed this invasive worm issue.

I couldn’t offer Sandy any advice on what to do and, in fact, there’s no recommended way to deal with invasive worms. Discarding fishing bait at the end of a fishing day is one way these worms spread. (Sandy’s husband does fish.) They also can be spread in potted plants and in composts that were insufficiently heated and in mulches. (Uh oh; what about all my leaf hauling?)

For all the compost I make and spread, and all the leaves and other organic materials I haul here to the farmden, I come upon surprisingly few worms. One did catch my eye the other day, something about the way it moved and its robustness.

A crazy snake worm

Crazy snake worm?

Could it be the European Lumbricus terrestris? Could it be the Asian “crazy snake worm”(probably Amynthas agrestis or A. tokioensis). Judging from the crazy way it moved and the pale collar (clitellum) circling its body completely, I’m guessing it’s one of the crazy snake worms.

Earthworms have always been a friend of gardener and farmer. Charles Darwin was a notable champion of them. After spending a lot of time on his belly in observation of these creatures, he wrote up his observations in a book, The Formation of Vegetable Mould through the Action of Worms. Darwin calculated that earthworms (probably Lumbricus terrestris) brought 18 tons of nutrient-rich castings to the surface per acre per year, in so doing tilling and aerating the soil while rendering nutrients more accessible for plant use. He wrote that “worms played a more important role in the history of the world than most persons would at first suppose.”

In our forests, European and Asian earthworms can eliminate leaf litter and change the soil composition to create conditions that favor non-native plants, decrease native plant biodiversity, and result in less understory vegetation. To the gardener and farmer, earthworms are a friend.

Greenhouse Happenings, Figs and Lettuce and . . .

Darkness Descending

Plant growth has come screeching (almost) to a halt. Lettuces just sit, hardly growing. No wonder, you are no doubt thinking. It’s getting colder and colder outside. I know that, but I’m writing about lettuces in my greenhouse. The issue isn’t lack of heat. It’s lack of light.Planting greenhouse lettuce

For more evidence that light is the issue, look to good vegetable gardens in southern Europe. In that mild climate, harvest from a well-planned vegetable garden continues year ‘round. But year ‘round harvest there takes planning — lack of light also makes for very slow growth over there in these darkest months. Unprotected plants survive because the winter weather never gets that cold over there. (And cool-season vegetables, such as spinach, radish, and turnips, that we plan for sprig or fall, are what do well in Mediterranean winters.)

My garden here in the Hudson Valley, at about the 42nd parallel, experiences winter day lengths the same as Rome, Italy or the island of Corsica — all on about the same 42nd degree of latitude. If lettuce plants grow slowly in Rome and Corsica, then the slow growth of lettuce in my greenhouse should come as no surprise. But it always does surprise me, and the brakes seem to start getting applied back in October, with full pressure about now.

All this came to the forefront of my attention back in 1992, when I read Eliot Coleman’s excellent book Four-Season Harvest. After highlighting the similar insolation of much of our “northern regions” with much of balmy Europe, he went on to describe various ways of protecting winter vegetable from our winter cold, which would kill most of them. Keeping the plants a bit warmer also gets them growing sooner once days become longer and brighter.

My goal, in the greenhouse, is to get a good share of the plants almost fully grown going into December. With lettuces, I try to plan to have enough of them to fill salad bowls through January and February, after which smaller plants are starting to grow fast enough to fill those bowls.

The 42nd Parallel

The reason Corsica and Rome remain relatively balmy all winter while winters here, with both locations at the 42nd parallel, get so frigid is that Corsica is bathed by the Gulf Stream, that warm mass of air that flows up from the Caribbean and across the Atlantic to wash over western Europe.

The warm touch of the Gulf Stream is lost as you move further east across Europe and into western Asia. Kazakhstan, parts of which also lie at the 42nd parallel, experience average annual temperatures from -60°F to 104°F!! The climate of nearby Turkey, whose north end touches that latitude, is moderated by the Caspian Sea. Moving further east to parts of Inner Mongolia, still within the 42nd parallel, winter temperatures might dip to -90°F.

A Greenhouse is not a Hothouse

If you were to join me in my greenhouse today, don’t forget your hat and gloves. The greenhouse is heated, but only minimally, enough to keep the temperature from falling below 37°F. That temperature provides a nice balance between energy use and reasonable year ‘round harvest. (Expotentially more energy is needed for incrementally increasing temperatures.)

Today is rainy and very cool, but not cool enough to kick on the greenhouse heater. So it’s pretty much the same temperature inside the greenhouse as outside the greenhouse — in the 40s. Most of what’s growing — kale, celery, mâche, claytonia, Swiss chard, mustard greens, parsley, and arugula — do fine with these conditions.

Leafy vegetables require less energy (i.e. sunlight) than do fruiting vegetables, so the low light is also fine to keep them happy even if only slowly growing, just as they would be planted (outdoors) in a garden in Corsica or Rome.

That’s also home to my baby, hardy cyclamens (about which I recently wrote), in a seed flat, until they decide to lose their leaves and go dormant. And two cardoon plants, also native to Mediterranean regions.

One Mediterranean plant that is very unhappy this year, even in the greenhouse, is fig. Figs are still ripening but, with the high humidity and low light, each is soon covered with fuzzy, gray mold. Figs rotting in greenhouseSplitting figRoots of Rabbi Samuel fig, near the endwall, spread under the wall and outside the greenhouse, soaking up so much water that the figs split before ripening. Yet, a few fig fruits escape both afflictions and ripen to juicy sweetness.

I wonder if fig gardeners in the Mediterranean share my fig problems.Eating a fig

Winter Prep for Some of my Figs

Fig Abuse?

Anyone watching what I was doing to my fig trees might have called “Fig Protective Services” to have my trees removed to a new home. But figs are tough plants and tolerate a lot of what looks like abuse.

Let me offer some background: Figs are subtropical plants so can’t survive to fruit outdoors around here. I grow a few fig trees in pots that I can put in a protected location for winter (more on that later). Problem is that the trees’ roots eventually fill the pots and exhaust  nutrients in the mix.

I could move each tree to a larger pot. Then the branches could grow commensurately larger, and more growth of branches translates to more figs to harvest. But these pots have to be moved every spring and fall, and there’s a limit to how big a pot I can handle.

The other way to give the roots new ground to explore is to root prune them. That is, slice off some roots to make space for new soil in the same pot. Trust me; I’ve done this for many years and the plants tolerate it well, growing happily each spring following the operation. (Fall or spring, when the plants are leafless, is the best time for root pruning and re-potting.)

So I tipped each plant on its side and pulled on the stem while holding the pot in place to slide the root ball out of the pot. Sliding root ball out of potAfter standing the root ball upright, I started slicing it from top to bottom. For root balls 18 to 24 inches across, I slice a couple inches off all around. I used to use an old kitchen knife but discovered that my reciprocating saw with a medium-tooth blade works much better.Slicing root ball

With the old root ball shrunken, it goes back into its pot and I start packing potting soil back in the space between the pared down root ball and the sides of the pot. Adding new potting soil to potFor good contact, I pack the potting soil in with my fingers and the flat end of a 3/4 inch dowel.Packing new soil in around root ball

Next year at this time or, at most, two years from now, trees will get root-pruned again.

Winter Quarters

Now, what will I do with the fig trees for winter. It’s a conundrum, because the trees, being subtropical, do well with a cold season rest, ideally below 50°. On the other hand, they can’t tolerate cold much below about 25°F. in their pots.

Some places that might provide temperatures within this range are an unheated garage that’s attached to a house, an unheated and uninsulated basement, or an unheated foyer or mudroom.  As long as they are dormant, the plants do not need light. 

For many years, I’ve lugged my plants down the rather narrow stairway to my basement. There’s an oil burner down there but it’s rarely used since most of our heat is with wood. In midwinter, basement temperatures hover around 40°F.

As of this year, my days of lugging the heavy pots down stairs are over. I now have access to a ground level, unheated room in a well-insulated, rarely heated building having a concrete floor for good thermal mass. The Ritz!

The goal is to keep the plants cold enough so that they stay dormant until it’s safe to move them outdoors in spring. If all goes well, the plants are still dormant when outdoor temperatures rarely dip below 32°F. Then the plants, moved outdoors, slowly awaken with cool temperatures and bright sun promoting sturdy growth.

Because fig trees in pots tolerate temperatures down into the 20s, there’s no rush to move them into storage. I usually wait until sometime in December.

What Makes Soil Potting Soil?

Notice that I mentioned my trees growing in “potting soil.” Straight soil, even good, well-drained garden soil, is unsuitable for plants in pots because it becomes unavoidably waterlogged. (The reason, described in my book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden, has to do with what is known as a “perched water table;” take my word for it or read the book.)The Ever Curious Gardener

Drainage is improved in potting soils by adding aggregate such as perlite, vermiculite, or calcined montmorillonite clay (the latter better known and more often sold as kitty litter).

Roots in containers have more limited volume to explore for nutrients, so potting soils also need to be richer that even good garden soils. Compost is one way to provide nutrition. Among the advantages of compost is its ability to offer nutrients over a long period of time, as soil microbes slowly decompose it.

Water, like nutrients, also must be accessed from a limited volume of soil. The compost helps a potting soil hold water; I boost that further with the addition of some peat moss or coir.

My finished mix is made up of equal parts garden soil, perlite, compost, and peat moss. All my plants, not just the figs, like it.

Peat, perlite, soil, and compost

Peat, perlite, soil, and compost