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PESKY CREATURES

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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.View of north garden

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. Cutworm damageThe 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.Cutworm and broccoli

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.Cutworm protection with stick

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.Slug

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.Flea beetle trolley

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.Garden view

Japanese beetles

JAPANESE & FLEA BEETLES, & LAISSEZ-FAIRE

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I grabbed the dustbuster as I walked out to the garden this morning, hoping to inaugurate a new era in Japanese beetle control, who began their summer feeding early this month. The dustbuster was ineffective, the beetles passively dropping from any leaf as soon as the nozzle came within a few inches. Even beetles caught in flagrante delicto decoupled and dropped.
This year’s approach to Japanese beetle control will be laissez-faire. Spraying a chemical insecticide like Sevin is too disruptive to the ecosystem. Most organic insecticides, such as neem oil and pyrethrum, are either of limited effectiveness or require too frequent reapplication. And anyway, the beetles attack too many different kinds of plants to make spraying feasible; I’ve got over a dozen varieties of grapes, a half dozen varieties of roses, many varieties of filberts, and a dozen hardy kiwi vines scattered all over the place, and these are just a few of the beetles’ favorites in my garden.
In past years, I’ve put traps a couple of hundred feet apart at either end of the property. Each morning, the catch bags were stuffed full of beetles. But many of those trapped beetles would not have been on-site were it not for the allure (from sexual and feeding attractants) of the traps. The traps seem to work best when only a few Japanese beetles are in the area.
Japanese beetles can get sick from a fungus that attacks them while they spend late summer to late spring in the soil as white, C-shaped grubs. You can purchase the disease, milky spore disease, with which to infect them. Problem is that the disease is of limited effectiveness: Not enough grubs sicken and die and, even if effective, beetles emerging in summer can fly over from neighbors’ untreated yards.
I’ll probably do a little handpicking, knocking or dropping beetles in early morning, while they are still drowsy, into soapy water, from which an escape is too slippery. Hand to hand combat is satisfying and surely effective (for the ones killed, at least). Japanese beetles emit an aroma that attracts more beetles, so hand to hand combat is also intellectually satisfying in the knowledge that each beetle killed means fewer new ones attracted.
The laissez-faire approach has its merits. Plants tolerate a certain amount of defoliation, the remaining greenery ratcheting up photosynthesis to make up for leaf loss.  And if the plants can just hang on for a few weeks, the beetles then begin their exit anyway, their attention turning to laying of eggs in the ground to hatch into grubs for next year’s beetles. Well watered, lush lawns provide ideal conditions for egg laying and grub development; ‘nuff said.
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Flea beetles, which have peppered the eggplants’ leaves full of holes, will not be emulating Japanese beetles and exiting stage left anytime soon. If you grow eggplants, you have flea beetles, except for perhaps the first year or two in a new garden, before the pests have found your site. Other favorites on flea beetles’ menu are radishes, arugula, and turnips.
Flea beetles, in contrast to Japanese beetles, can be feasibly thwarted. A dustbuster, in this case, can be effective if used frequently enough. A thick mulch might interfere with their emergence from the soil. Fine mesh fabrics, — “floating row covers” — act as barriers although I like to be able to see my plants and the cover has to be removed during bloom to allow for pollination of eggplants.
Mostly, flea beetles are a concern with young seedlings, which can be killed, and for commercial growers, because customers don’t like to buy hole-y vegetables. 
Flea beetles hop away when disturbed and my favorite way to do them in is with the “flea beetle trolley” described on page 144 of Lawrence D. Hill’s Grow Your own Vegetables (Faber and Faber, 1971). Quoting Mr. Hill, “A wire in front disturbs the beetles which jump up and stick to the greaseband [flypaper or paper coated with Tangletrap would also work well]. The large wheels prevent sideways jumping.” The trolley works best on masses of leaves of small plants, such as radishes or arugula, rather than on widely spaced, larger plants with tiers of leaves.
Hot pepper may repel flea beetles. Research suggests that commercial “hot pepper wax” reduced flea beetle damage by about a half, so it may be worth a try.
I might take the laissez-faire approach to flea beetles as well as Japanese beetles. I’ll keep in mind that established plants tolerate 10 to 30% loss of leaf area without ill effect.
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Sometimes it pays to look closely at your garden plants; sometimes it doesn’t. My general tack with plant pests starts with offering my plants the best possible growing conditions. This means soil that drains adequately and is enriched with plenty of compost and other organic materials to provide nutrients and a friendly microbial environment. It means providing water, as needed. And it means allowing for adequate plant spacing and light. Still, it’s a wide world of insects, fungi, bacteria, and viruses out there, as well as capricious weather, so there’s no reason to expect perfection from each leaf and fruit. Much damage is nothing more than cosmetic and is tolerated by plants. 
One nicety of home-grown fruits and vegetables is that there’s no monetary profit needing to be optimized. So some amount of damage is, and also should be, tolerated by us home gardeners.
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