Pests – Lee Reich

A GARDEN PEST OF HUMANS

September 11, 2024/4 Comments/in Pests/by Lee Reich

Yellowjacket Frenemies

Not all garden pests attack plants. One pest, not of plants, that especially bugs me around this time most years is yellowjackets. Yellowjackets can be worse than irksome; they can be deadly to people allergic to their sting.

Whether deadly or just irksome, yellowjackets are amongst the orneriest of creatures. They are aggressive and, unlike honeybees, don’t have to stop after one sting. Burying its stinger in your arm has no effect on a yellowjacket’s mortality, so it can do it again if it so pleases or go on to seek out other victims.

As with all of Mother Nature’s creatures, yellowjackets are not all bad — even from the biased viewpoint of us humans. Read more

DAMN-PING OFF

April 10, 2024/0 Comments/in Pests/by Lee Reich

Worse than Roman Warriors

I made my first gardening enemies decades ago, within a few weeks of starting my first garden. Not other gardeners but — and perhaps you also have crossed paths with them — with Pythium, Rhizoctonia, and Fusarium. I quickly learned that they were, or should be, hateful not only to me but to all gardeners.

Pythium, Rhizoctonia, and Fusarium are not ancient Roman warriors; they are fungi and, worse than Roman warriors, they lurk everywhere. When they, or one of them, gets the upper hand they cause damping off disease.

Let’s return to my first garden: At the time, decades ago, I was living in a relatively dark apartment, a converted motel room, and was eager to start my first seedlings. I sowed all sorts of seeds in peat pots, stood them in a little water, then crowded them together on all the shelf space that could be mustered.

Young sprouts never appeared in some of the pots. In others, seedlings emerged, then toppled over, their “ankles” reduced to a withered string of rotted cells unable to support the small plants physically or physiologically. Read more

OCCULT PRACTICES?

January 3, 2024/5 Comments/in Pests, Soil/by Lee Reich

Potash Kalium Connection

I wonder if my neighbors suspect that I’m engaging in some sort of occult ritual as I take rounds through the farmden followed by puffs of grey smoke. Perhaps I’m entreating tiny gnomes living within the soil to keep weeds at bay next season? Or begging garden gremlins to make my soil fertile? No, and again no! I’m merely spreading wood ashes.

I must be careful with my terminology: I’m not dumping wood ashes; I’m fertilizing my soil with wood ashes. Wood ash is a rich source of potassium, a nutrient required by plants in amounts second only to nitrogen. Potassium helps build strong stems and helps plants resist disease. It also regulates the opening and closing of stomata, the tiny pores in leaves through which gases pass for photosynthesis.

The close connection between potassium and wood ash is reflected in a traditional source of, and the root of the word, potassium — “potash.” Read more

FOR THAT UNWELCOME MEDITERRANEAN LOOK

July 11, 2023/4 Comments/in Pests/by Lee Reich

One Name for Many Diseases

The powdery white coating I notice on leaves of my peony and lilac plants gives them a very Mediterranean look. Not attractive, though, at least to me, because that’s a sign of a disease, appropriately called powdery mildew. If I look around the garden, the disease is probably showing itself, or soon to do so, on a wide variety of plants, including phlox, zinnia, squash, gooseberry, and many more. (This blog post is excerpted from the chapter about plant stresses in my book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden.) Even though powdery mildew is pretty reliable in showing up each season on certain plants — this is important! — the disease doesn’t necessarily spread from one kind of susceptible plant to the next. Many different fungi are responsible for the disease we collectively call powdery mildew, and each of these fungi have specific plant hosts. Thus, the fungus that causes powdery mildew on lilac (the fungus is Microsphaera alni) cannot cause powdery mildew on rose (caused by the fungus Sphaerotheca pannosa). Read more

PESKY CREATURES

May 17, 2023/4 Comments/in Pests/by Lee Reich

Vegetables are Easy, But . . .

I consider vegetables generally easy to grow, especially if you grow lots of different kinds. If one kind does poorly one year, there are lots of other vegetables in the garden doing well, and there are other years.

Still, vegetable — and flower — transplants are especially apt to suffer attacks from three pests this time of year, each leaving a telltale clue to its presence or handiwork. Stems might be chopped off at the soil line. Leaves might be chewed. Or leaves might be shot full of tiny holes. The culprits? Respectively: cutworms, slugs, and flea beetles.

All three culprits have cosmopolitan tastes, attacking practically any transplant you set out. Fortunately, these pests can be controlled to some degree without toxic (to you, and nontarget creatures) sprays, usually without resort to any sprays.

A Few, But Deadly, Bites

Cutworms take only a few bites out of new transplants, which would not be reprehensible if those few bites were not at ground level. Seedlings topple and, because they are just seedlings, never recover. The damage should not be confused with damping-off disease, which is a fungus that also attacks at the soil line, but only afflicts newly emerged seedlings. To make sure, scratch with your finger in the soil near the toppled plant and look for the bugger. Then squish it.

Cutworms are easily repulsed with some sort of barrier, such as a cardboard collar around each plant. Toilet paper tubes cut a couple of inches long are convenient for this purpose. Surround each transplant and press the collar a half-inch or so into the soil.

Before a cutworm takes a bite of a plant, it wraps its body around the plant’s stem to make sure the stem is tender enough to bite into. Once stems of vegetable and flower transplants toughen, cutworms leave them alone.

I used to fool cutworms by sticking one toothpick in the ground right up against each of my transplants. It worked. The insects think they are embracing small, woody-stemmed trees and leave the young plants alone.

Another method to foil cutworms (which I have not tried) is to trap them in foot-deep holes, made with a broom handle or an inch-thick dowel. As daylight approaches, the cutworms climb into these holes for shelter. What the cutworms do not realize is that they are incapable of ever climbing back out.

The life of the cutworm is not easy: this pest is also food for birds and ground beetles, and is parasitized by certain small wasps.

I have to admit that I haven’t used any of these cutworm control methods for years and years. I never see cutworms or their damage anymore. I’d like to think that it’s evidence of my having a green thumb, but much more likely are the robins and morning doves that I see patrolling my garden early every morning.

Slimy Slitherers

Moving on to slugs . . . these creatures love wet weather. Slugs slither around at night and by morning their presence is made known by the shiny trails and ragged leaves they have left. Here in the Northeast, they are up to a couple of inches long. In other parts of the country, they get as large as a half a foot or more long.

Slugs don’t like anything sharp or caustic rubbing against their slimy bodies, so if you sprinkle a circle of sharp sand, diatomaceous earth, or woodashes around your plants, a slug will think twice before crossing this barrier. Unfortunately, these barriers must be renewed after rains, which is when slugs are most active.

You could take a flashlight into the garden at night and sneak up on slugs while they are at work. They are slippery to handpick, so take along a saltshaker. Sprinkling salt on them will kill them. It’s gruesome to watch, but very effective.

Beer is a somewhat effective poison bait for slugs. Put some beer — Budweiser is one of the best — in a shallow pan or cqn and sink it into the ground so the lip is about one inch above ground level. Almost immediately slugs will start inching to their demise.

A bait containing iron phosphate is very effective agains slugs, and considered nontoxic to just about everything else, including humans.

No need to open a fresh bottle each night, for slugs are happy even with stale beer. Some gardeners report good results with only yeast plus water. You might need lots of traps because slugs won’t “hear” the siren song of beer beyond a few feet.

A Different Kind of “Flea”

Flea beetles, which perforate leaves with small holes, are the most difficult of the three pests to control without pesticides. You may not notice the beetles because they’re only a couple of millimeters long and hop away when approached. Fleabeetles on eggplant

Lawrence D. Hills, in his 1974 book Grow Your Own Fruit and Vegetables, describes a contraption he put together himself. It looks like a high-riding skateboard, with a long handle at the top of the middle and a horizontal metal wire down across the front of the board. He tacked flypaper on the underside of the board. (Tangletrap© spread on the underside would work as well, or better.) As you push this contraption over a row of plants, the wire disturbs each leaf — and the flea beetles. Flea beetles hop away when disturbed; for these flea beetles, it’s their final hop as they get stuck on the flypaper.

Predatory nematodes, which you can purchase, might also limit flea beetle damage by attacking eggs in the soil. I added predatory nematodes that have the potential to perennialize to my soil, available from the Shields Lab at Cornell University. These have been shown to be effective against some pests that spend part of their lives in the ground. Patience is needed as their numbers multiply.

Flea beetles are especially fond of cabbage and its kin, as well as spinach, beets, and potatoes. They’re mostly a problem on my eggplants; actually, just about everybody’s eggplants. I and many other gardeners and farmers thwart them, by covering plants with a barrier of a “floating row cover.” These lightweight materials, made from spunbonded or woven synthetic materials, are permeable to water, air, and sun, but impermeable to insects. The barrier must be in place before seedlings emerge or right after setting out transplants.

Sometimes it’s appropriate just to ignore pest damage, for awhile, at least. Small transplants often outgrow flea beetle or slug damage, provided the plants are growing rapidly enough and the pests are not too many or too hungry.

MORE OF MY FAVORITE TH . . . GRAPE VARIETIES

September 21, 2022/3 Comments/in Pests/by Lee Reich

The Birds and the B . . . Vespids

Hot and dry. What great summer weather it’s been here for grapes. Most years around this date, I’d go out every morning and pick bunches for fresh eating, continuing to do so for weeks to come. Basket of grapes

Alas, where there are grapes, you’ll find the birds and the be. . . vespids (the family of wasps and hornets, not bees). No raccoons or foxes, here on my grapes, at least. Here you’ll also find paper bags stapled around about a hundred bunches.

The bags are meant to protect the enclosed bunches from birds and insects. This year was a first: Thirsty birds pecked holes in the bags through which they could reach, then peck at the grapes hanging within. By my estimate, about three-quarters of the bagged bunches suffered damage or were finished off in toto.

In addition to the damage inflicted by the birds, the resulting holey bags provide easy entrance to wasps and hornets, who further tear up the bag and finish off the fruit repast started by birds.

COMPOST TEA REVEALED

August 24, 2022/3 Comments/in Pests, Soil/by Lee Reich

First Step, Identification

A few years ago I went to a nearby permaculture convergence. (Actually a “permaculture conference; those people have the best terms for what they do). I’ve grown plants in what I learned was a permie way for many decades, so I’ve been accused of being a permaculturalist. I was even invited to do a presentation and host a farmden tour for the convergence.

While there, I had the opportunity to attend a lecture by someone who has been billed as the diva of dirt, or, at least, of compost tea, specifically aerated compost tea (ACT), Dr. Elaine Ingham. You’ve never heard of ACT!? It became the hot, new thing years ago, perhaps still is, as an alleged cure for poor soil and plant pests. I’d been skeptical and thought that hearing and speaking to Dr. Ingham in person could entice me into the fold. Making compost tea

Dr. Ingham showed myriad images of fungi, nematodes, and other creatures that you might find in compost piles and teas. We saw many “bad guys” that lurk in poorly aerated composts and teas. The “bad guys” are bad, she asserted, because they release toxins into the soil and puff away valuable nitrogen, sulfur, and phosphorus in various forms as gases.

Dr. Ingham suggested monitoring our compost piles and tea happenings by purchasing a microscope and, with the help of her workshops, identifying resident microorganisms. Hmmm; interesting, but is it really necessary for a green thumb?

While the panoply of microorganisms discussed was impressive, I contend that even a well-aerated compost pile or tea is bound to have some poorly aerated pockets. It’s not a “bad guys” vs. “good guys” situation, but a question of generally favoring an excess of “good guys.” Also, once compost is spread on the ground, the large surface area presented is going to tip the balance even more in favor of aerobic conditions.

To identify what organisms are in a compost pile, you have to get them out of the pile and onto a microscope slide. Easy. Just soak some compost in water and strain it. Or use a compost teabag. But wait! Is that really the spectrum of microorganisms that call that compost home? Not necessarily. What are staring up at you from that microscope slide are creatures that can be leached most readily into water. What you see also might depend on how long you steeped the teabag and who can squeeze out into the water through whatever size holes are offered by the strainer or the teabag.

Will Compost Microbes be Happy Far from their Compost Home? More fundamentally, I question basic assumptions underlying the use of compost tea. Even if you have beneficial organisms in hand (figuratively) and sprinkle them on the ground, they’re bound to expire unless the environment is suitable. Microorganisms in the tea might have enjoyed life within the dark, moist innards of a compost pile; the soil environment ain’t nothin’ like home for them.

Spraying ACT or any compost tea on plant leaves should likewise have little or no effect on plant diseases; again, conditions on a leaf surface aren’t conducive to their survival. In the evolutionary scheme of things, why would a microorganism that thrives in the dark, moist, nutrient-rich innards of a compost pile survive on the sunny, dry, nutrient-poor surface of a plant leaf, let alone provide any benefits? Spraying plants

Over the last few decades, people have spritzed plants and sprinkled soils with compost tea, looking for effects such as improved soil structure or drainage or increased plant resistance to pests. Independent well-designed, vetted studies do not generally support claims made for compost tea.

True, there are some studies that show some benefits. I contend that if you spray just about anything on a plant leaf and have enough plants in the study along with sufficiently detailed measurements, some statistically significant effect might be noted. But every statistically significant effect isn’t also biologically significant. And looking over a number of studies, some few show a benefit from compost tea, many demonstrate no effect, and for a number of them, the effect of compost tea is detrimental.

Soluble nutrients do leach out of a compost teabag into water. The resulting compost tea, then, becomes a liquid feed for plants, effective either poured on the ground or even sprayed on leaves. So there can be some benefit from compost tea, a nutrient effect, not a microbial one.

Bulk is Good

Except in special situations, soil environments naturally host microorganisms that thrive best in them. A similar situation exists with earthworms. Years ago, perhaps still, advertisements in the back pages of gardening magazines would offer earthworms for sale. The reasoning went that good soils are teeming with earthworms, so purchasing and importing these creatures to you garden will make your soil better. Not true. The earthworms will die out if conditions and food are not to their liking. The same goes for microorganisms.

(An example of an exception to what I wrote in the previous paragraph is a study that was done in Puerto Rico back in 1950. THE USDA was trying, with little success to introduce a more useful, but non-native pine, to the island territory. Mycorrhizae are fungal symbionts that infect practically all plants; the fungus gets some foods manufactured by the plant in return for moving more nutrients and water to the plant for improved growth. The appropriate fungal symbiont was lacking in Puerto Rican soils. After inoculating plants with an appropriate fungus, the inoculated, introduced pines grew six times more than their introduced brethren that had not been inoculated.) Compost being shovelled

Except in rare situations, as in the example above, earthworms, microorganisms, and other creatures generally inhabit environments most congenial to their flourishing. Perhaps not enough of them, and what they really need is food to give their populations a boost, and food means some form of organic material. That is, bulky organic materials, such as compost, manure, leaves, and straw.

Good gardening comes form using a pitchfork, not an elixir. Does anybody still make and use compost tea?

A BACTERIA TO THE RESCUE

July 28, 2022/6 Comments/in Pests/by Lee Reich

A Cabbageworm is a Cabbageworm is a . . . Not!

A few weeks ago, one or more of the few species of “cabbageworms” began munching the leaves of my cabbage and Brussels sprouts plants. They ignored kale leaves, thankfully, because it’s my favorite of the three.

Cabbageworm damage

A laissez fair approach would have left the cabbages and Brussels sprouts mere skeletons, so I had to take some sort of action.

For the record, “cabbageworms” are actually not worms, but a few species of caterpillars all classified — and this is important — in the order Lepidoptera. Here’s the lineup: A cabbage looper arches its back when moving, and is light green with a pale white stripe along each of its sides and two thin white stripes down its back.

Cabbage looper

A diamondback moth larvae is 5/16 inch long, yellowish-green, and spindle shaped with a forked tail.

Diamondback moth larva

A cabbageworm (yes, one kind of cabbageworm is named “cabbageworm”) is one-and-a-quarter inches long, velvety green, and has a narrow, light yellow stripe down the middle of its back.

Cabbageworm & cross-striped cabbageworm

A cross-striped cabbageworm is 3/4 inch long and bluish-gray in color with many black stripes running cross-wise on its back, below which a black and yellow stripe runs along the length of its body.

Natural Control

I put an end to whichever “worms” were the culprits, and was able to do so without resorting to any chemical spray, by spraying the plants with Bt. Bt is the commonly used abbreviation for Bacillus thuringiensis, a bacterium that causes disease in certain insects. After ingesting Bt, a cabbageworm becomes sick, stops eating, and dies. Since the Bt I sprayed is toxic only to lepidopterous insects, it doesn’t pose any danger to other creatures, such as birds, cats, dogs, humans, and even other insects.

The insecticidal properties of Bt have been known since early in the twentieth century, when the bacterium was discovered as a silkworm pest by Japanese researchers. (Silkworms are also Lepidoptera.) The originally discovered strain of this bacteria is toxic only to caterpillars, which are larvae of butterflies and moths, and was first used purposefully to control the European corn borer in Europe in the 1930s. Interest in Bt waned in the late 1940s, when nerve gases used during World War II led to the development of new types of chemical pesticides. In the 1960s, agricultural scientists finally began to take a second look at Bt.

Many strains of Bt have been isolated. The ones for cabbageworms and other Lepidoptera are Bt aizawai and Bt kurstaki. Thuricide label The strain Bt var. israelensis is toxic to larvae of black flies and mosquitoes. Another strain, Bt var. san diego, is toxic to Colorado potato beetle larvae.

All these strains of Bt are available commercially. The bacteria are packaged in a dormant condition either as a dry powder, a liquid suspension, or, in the case of Bt var. israelensis, a slow release ring that is floated on water to kill mosquito larvae. Bt goes under a number of brand names which don’t give a hint of the pesticide’s ingredients, so read the label to make sure of what you are buying. The product I use goes under the trade name Thuricide.

Bt is a living organism, so I store it in such a way as to prolong its viability. (Here on the farmden, Bt resides in the back of the refrigerator, which is generally a strong no-no for pesticides. (But Bt is nontoxic, and there are no children in the house.) Kept cool and dry, the bacteria will remain viable in its container for two or three years. Bt works quickly enough so I can check for discolored, blackened, or shriveled larvae the next day to see if the spray is still viable.

But . . .

Is there some trade-off that must be made when using this apparently benign pesticide? Yes, insect pests can develop resistance to Bt, just as they do to chemical pesticides. Resistance is most likely from continuous, repetitive use of any single pesticide, or different ones with the same mode of action.

This problem, with Bt, has been exacerbated since almost 500 million acres of crops, mostly field corn and cotton, have been genetically engineered with insecticidal Bt genes. It’s equivalent to the field being constantly sprayed with Bt. Some resistance has been found.

In my garden, I apply Bt at the recommended rate, only to afflicted plants, and only when a pest problem gets sufficiently out of hand to warrant treatment.

There’s another good reason for careful use of at least the original strain of Bt. Since this strain is toxic to caterpillars, indiscriminate use could substantially decrease the caterpillar population and, hence, the numbers of moths and butterflies. My distaste for the celeryworm, which has a voracious appetite for carrot, celery, and parsley leaves, is tempered by the beauty of its adult form.

Celeryworm

Surely the elegance and grace of the adult form, the black swallowtail butterfly fluttering about the garden, adds as much beauty as a marigold or rose.

Black swallowtail

HEAT? DROUGHT? NO PROBLEM.

July 20, 2022/6 Comments/in Gardening, Pests/by Lee Reich

Physiological Workaround

Portulaca is a genus that gives us a vegetable, a weed, and a flower. All flourish undaunted by heat or drought, a comforting thought as I drag the hose or lug a watering can around to keep beebalm, an Edelweiss grapevine, and some marigolds and zinnias — all planted within the last couple of weeks — alive.

Portulaca employ a special trick for dealing with hot, dry weather, which presents most plants with a conundrum. On the one hand, should a plant open the pores of its leaves to let water escape to cool the plant, as well as take in carbon dioxide which, along with sunlight, is needed for photosynthesis. On the other hand, the soil might not be sufficiently moist or the pores might end up jettisoning water faster than roots can drink it in, in which case closing the pores would be the ticket.

Portulaca gets around this conundrum by working the night shift, opening its pores only in darkness, when little water is lost, and latching onto carbon dioxide at night by incorporating it into malic acid, which is stored until the next day. Come daylight, the pores close up, conserving water, and malic acid comes apart to release carbon dioxide within the plant. I describe this specialized type of metabolism in my book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden.

From the Pampas to my Garden

Let’s start with the flower Portulaca, P. grandiflora, which goes either by a common name that is the same as the generic name, or by the name “moss rose.” In truth, the plant is neither a moss nor a rose. But the tufts of lanceolate leaves do bear some resemblance to moss, a very large moss. And portulaca’s flowers, which are an inch across, with single or double rows of petals in colors from white to yellow to rose, scarlet, and deep red, are definitely rose-like. The plant grows to a half-foot-wide mound, with stems that are just barely able to pull themselves up off the ground under the weight of their fleshy leaves. Moss rose

Moss rose is native to sunny, dry foothills that rise up along the western boundary of the South American pampas. As might be inferred from its native habitat, this plant not only tolerates, but absolutely requires, full sun and well-drained soil. Such requirements, and low stature, make the plant ideal for dry rock gardens and for edging.

Moss rose is easy to grow from seeds sown at their final home, or started in flats for transplanting. Some gardeners mix the extremely fine seed with dry sand before sowing, to ensure uniform distribution.

Once blossoming begins, it continues nonstop until plants are snuffed out by frost. Moss rose is an annual, but sometimes will seed itself the next season. However, double varieties (plants with double rows of petals) grown this year will self-seed single varieties (plants with a row of petals) “volunteers” next year.

Plant It or Not, It Will Be There

The vegetable and the weedy Portulaca can be dealt with together; they are one and the same plant, P. oleracea. Somewhere in your garden now, you surely have this plant, whose succulent, reddish stems and succulent, spoon-shaped leaves hug the ground and creep outward in an ever-enlarging circle.

The common name is purslane, though it has many aliases, including pussley, Indian cress, and the descriptive Malawi moniker of “the buttocks of the wife of a chief.”

Tenacity to life and fecundity accord purslane weed status. Pull out a plant and toss it on the ground, and it will retain turgidity long enough to re-root. Chop the stems with a hoe, and each piece will take root. Even without roots, the inconspicuous flowers stay alive long enough to make and spread seeds.

My one consolation with having this weed in my garden is that it’s easy to remove, robs little nutrients or water from surrounding plants, and, being low-growing, casts little or no shade. Perhaps it even protects the soil surface from sun beating down on it or pounding raindrops from washing away soil. On the other hand, left unattended, it could take over a garden this time of year.

You Could Eat It

What about purslane, the vegetable? Take a bite. The young stems and leaves are tender and juicy, with a slight, yet refreshing, tartness. Purslane is delicious (to some people, admittedly not to me) raw or cooked, and is much appreciated as a vegetable in many places around the world besides its native India.

I have actually tasted the result of the plant’s specialized metabolism in summer by nibbling a leaf of purslane at night and then another one in the afternoon. Malic acid makes the night-harvested purslane more tart than the one harvested in daylight.

There are cultivated varieties of purslane for planting(!) in the vegetable garden. These varieties have yellowish leaves and a more upright growth habit than the wild forms. Wild or cultivated, the plants can be grown from seed or, of course, by rooting cuttings from established plants.

As far as actually planting purslane in my garden, I agree with the view of another garden writer who said “it is a reckless gardener who would plant purslane.” That does not mean that I do not grow purslane, though, for plenty keeps appearing despite my weeding.

Every once in a while, I again try eating it. I have enjoyed it in salads in restaurants to such accompaniments (or taste and texture disguisers) as feta cheese, olive oil, vinegar, and other strong flavors.

If you do opt to plant purslane, you must replant it yearly. Like the moss rose, purslane is an annual plant. Once established in the spring, both purslane and moss rose need no further care. Now, if only moss rose were a bit more weedy . . .

And Never the Twains Shall Meet

December 8, 2021/15 Comments/in Flowers, Fruit, Pests/by Lee Reich

Detente, Plant Style

“Oh, East is East, and West is West, and never the twain shall meet,” wrote Kipling a hundred years ago. Not so with respect to gardening. The Far East, spared the great sheets of ice that descended upon North America during the Ice Ages, has been a treasure trove of plants. Though distance, water, and culture kept the gardening worlds of the East and the West separate for millennia, the gap began to narrow just over two-hundred years ago.

The first plants to trickle out of China were those plants most accessible to foreigners — cultivated plants growing at and around seaport towns. It was not until the

Potted kumquat

middle of the nineteenth century that plant explorers pressed inland to open wide the treasure chest of wild and cultivated plants, many of which have found their way into my garden. These plant explorers are honored in plants that bear their names. Fortunella, or kumquats (the genus was changed recently, with kumquats now in Citrus), named for Robert Fortune. I grew kumquats, wintering them indoors at a sunny window, for many years. Citrus meyerei, the Meyer lemon, named for Frank Meyer; my two Meyer lemon plants, also at sunny windows, are just beginning to send out new shoots, soon, with flowers.

(There is a darker side to “East meets West.” Up until the middle of the 19th century, Japan was isolationist, which was not to the liking of U.S. commercial interests. President Millard Fillmore enlisted “Admiral” Matthew Perry to force his boats into Japan’s Edo Bay to intimidate the Japanese into opening their ports to American trade, as well as other concessions. This gunboat diplomacy was successful.)

Meyer lemon in bloom

Trans-Pacific Cousins

From the Far East came plants for which we had no counterparts, plants such as the gingko tree. There also came plants more, or at least equally, valuable as related plants found here. We have our redcedar (Juniperus virginiana); from China comes Chinese juniper (J. chinensis). Our redcedars turn drab brown in winter, but the Chinese species remain lush green throughout the year.

Common witchhazel (Hamemalis virginiana) and vernal witchhazel (H. vernalis) are understory shrubs of American forests; Asian forests likewise have two witchhazel

Arnold’s Promise witchhazel, today

species: Chinese (H. mollis) and the Japanese (H. japonica). The Asian species blossom at different times than the American species, so are useful for extending the period of witchhazel bloom. My Arnold’s Promise variety of witchhazel, a hybrid of the Chinese and the Japanese species, is in bloom right now although blooms often wait until midwinter to open

Where East really does meet West in gardening is in hybrids of Eastern and Western species. The hybrid tea rose, common in American gardens from New England to the Southwest, is one example. “Tea” in the name traces back to a tea-scented rose (Rosa gigantea) from China. For centuries, the Chinese hybridized this summer-flowering climber having huge, yellow flowers with a dwarf form of another species, R. chinensis. In the nineteenth century these hybrids were further hybridized with European roses to make hybrid tea roses.

Pest Control

American plant breeders sometimes have had to look across the Pacific to find plants with resistance to a disease originally brought to America from the East. Chestnut blight turned up at New York’s Bronx Zoo in 1906, and within fifty years, the tops of American chestnuts (Castanea dentata) were dead or dying in seven million acres of Appalachian forests. The roots, which are not affected by the blight, keep sprouting new shoots, which then die after a few years, but keep the blight fungus “fed.”

Blight on chestnut bark

Japanese chestnut (C. crenata) and Chinese chestnut (C. mollisima) evolved with the blight and show some resistance to it, so have been hybridized with the American species to produce blight-resistant trees, such as the variety Sleeping Giant. These trees lack the grandeur of the American chestnut, but they do make larger nuts. My chestnuts, the varieties Colossal, Marigoule, and Precoce Marigoule, are hybrids of European chestnut (C. sativa) and Japanese chestnut. They’re all blight resistant, but resistance is a matter of degree. My Colossal is finally succumbing to blight.

Dutch elm disease entered America via Europe, but entered Europe from Asia, probably about the time of World War I. Once again, Asian elm species — Chinese elm (Ulmus parviflora) and Siberian elm (U. pumila) — are resistant to the disease. Hybridization has produced such disease-resistant varieties as Patriot and Accolade.

Plants of Asia even have been useful in providing resistance to diseases not originating in Asia. Fireblight disease of pears was first noted in New York’s Hudson Valley at the end of the eighteenth century. Some Asian pear species are resistant to fireblight. Over a hundred years ago, hybrids between Asian and European pears that showed some resistance to blight were produced, at first by accident. These original hybrids did not taste very good, but did make pear-growing possible in blight-prone southeastern U.S.

The story isn’t yet over. Expeditions still return from such areas as remote villages and forest of China and the Himalayas to yield “new” plant treasures.