THINGS NOT SO ROSEY

Lest anyone believe that everything is always rosy here on the farmden, it ain’t so. True, right now, vegetable beds are brimming over with crisp, tender heads of delicious lettuce, broccoli, endive, and cabbage, and upright stalks of aromatic celery and leek. And, yes, the floor of the greenhouse is verdant with developing, young lettuce, large, leafy kale and Swiss chard plants, and 10 foot tall fig trees bearing fruits

But let’s start with those figs, three different varieties of which live with their roots right in the ground in the greenhouse. Green Ischia has been bearing large, copper-colored, firm, sweet fruits for weeks and weeks. No problem here.

About 8 feet from the Green Ischia grows a Brown Turkey fig. It kicked off the season as usual, loaded with fruit that started ripening in early September. Then scale insects moved in, dotting stems and eventually the fruits with their gray bodies, and sucking the life out of everything until the harvest petered away to almost nothing

About 8 feet from the Brown Turkey tree grows another fig tree, Kadota, with fruits lined up along its stems also. From past experience, I expected problems with Kadota. It’s a delectable and heavy yielder that thrives in hot, dry climates. The greenhouse is hot but hardly dry. With the high humidity in there, almost every Kadota fig has turned to a fuzzy, white ball just before ripening.

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The Kadota problem is the one most easily solved. That white fuzz is fungal, and the fungal culprit is probably Botrytis cinerea, a cosmopolitan fungus boasting a slew of host plants. Botrytis claims credit, for example, for a wet spring’s fuzzy, gray strawberries, for a wet summer’s fuzzy, gray raspberries, and, in a more benevolent form, for “noble rot” of grapes, which makes for a sought-after wine. All sorts of ominous chemicals can control botrytis. More benignly, on stored fruits at least, it has been controlled with a 1% solution of baking soda, or an atmosphere of either 15 ppm acetic acid (i.e. vinegar) or 75 ppm cinnamaldehyde, the natural flavoring of cinnamon

Trying to control disease on my Kadota figs with sprays would be an uphill battle considering the perfect conditions for botrytis: a very susceptible variety of fig, a very humid environment, and presence of the fungus. My approach is straightforward, and that is to dig up Kadota and plant a more disease-resistant variety in its place

On to Brown Turkey . . . Scale insects get up into plants and move around with the help of ants. Stopping the ants goes a long way to putting the brakes on scale. Stopping the ants is easy: Masking tape wrapped around the trunk and coated with a continuous ring of sticky Tanglefoot Tangle-Trap Insect Trap Coating. I also, of course, have to make sure there are no leafy, stemmy, or other bridges around which ants can detour. Next year

One other possibility for reining in scale insects is to spray “summer oil” in spring after the plants have leafed out and greenhouse beds are clear of lettuce, kale, and other vegetables. Summer oil is highly refined so as not to damage plants while it’s smothering the scale insects.

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Another problem I notice in the greenhouse is that developing lettuce heads have some hole-y leaves and a few gobs of insect poop. Slugs are the usual, occasional problem in my greenhouse, but they don’t leave green, gobby, poopy calling cards. (No less unpleasant are the silvery trails they do leave, from their dried slime.) With more than usual grasshoppers this year, that was also a possibility. Nix on that. I just haven’t seen enough of them for all that poop, and they chew beginning at the edges of leaves. Attacked lettuce leaves were pocked with holes

The feeding resembles the handiwork of cabbageworms or cabbage loopers. They’ve never before indicated a liking for my lettuce but are known to include lettuce in their diet. Yet another possibility is another caterpillar, armyworm. This one feeds at night and, because I haven’t seen any caterpillars, is now the most likely culprit

The natural insecticide, Bt (sold under such trade names as Dipel and Thuricide), that I mentioned last week is very effective against the cabbageworms and loopers, as well as young armyworms. Larger armyworms are finished or just about finished feeding anyway.

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These few problems notwithstanding, things are still rose-y, or at least carnation-y, in the greenhouse. The big, fat, fragrant ‘Enfant de Nice’ carnations that I grew this summer . . . well, I couldn’t just leave them out to die from cold. So I dug up some plants to grow in the greenhouse. They add a nice spot of red, white, or pink color, and the fragrance is, as billed, “intoxicating spicy-sweet clove.”

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KEEP OFF THE SCALE

Shortening days and cooling temperatures have certain potted plants crying out to be brought indoors. Soon, soon. Subtropical plants, such as bay laurel, rosemary, and fig, tolerate -- even enjoy -- temperatures below freezing, so cold isn’t the threat, for the next few weeks at least. But the later the evergreen plants come indoors, the more chance that I will have fired up the woodstove. The resulting drier air will shock plants if they’ve recently come in from cool, moist outdoor conditions; leaves will yellow and drop.

As for my poinsettia, staghorn fern, orchids, and other tropical plants, temperatures that dip below freezing could do them in.

But nobody’s coming indoors yet. First I have to make sure that no creatures are hitchhiking in with the plants. No, not creatures that would threaten me, but creatures that would threaten the plants themselves, and those would be mostly scale insects. Outdoors, ladybird beetles, parasitic wasps, some fungi, and other natural predators and diseases keep scale populations more or less in check. Indoors, plants are on their own.

Scale insects are so named for the waxy covering that protects the adults. They need that protection because once they start sucking plant juices through their straw-like stylets, they settle down in one place for good. Infested plants become weakened and the insects secrete a sticky honeydew that drips on the plant and surrounding furniture and carpet. A dark-colored fungus feeds on this honeydew, blackening leaves and surroundings. Blackening of the leaves, although superficial (the fungus isn’t attacking the plant), further weakens the plant by shading it from light.

Scale trivia: Male scale insects die after a couple of days without ever feeding. Some scale species consist only of females. Some scale insects are herded by ants who move them about and protect them from predators; in return ants “milk” the insects for their sweet honeydew. And not all scale insects are bad. Red cochineal dye comes from a scale insect, as does lacquer.

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For the past few weeks, once a week, I’ve taken out my arsenal against scale insects. Insecticidal soap is relatively nontoxic and is a kind of soap especially formulated to kill soft-bodied insects. Two teaspoons of mild detergent in a gallon of water is also effective.

Repeated applications are needed because the soap is ineffective against scale insects protected by their covering. It’s the little ones, the “crawlers,” as they are called, that I’m gunning for. After birth, they scoot out from beneath their mother’s protective cover to find their own sucking spots, and that’s when they’re most vulnerable to soap. My goal is to keep at it to kill each hatching until there’s no more fecund mothers still giving birth. If the soap merely knocks crawlers off the plant, a subsequent spray will also kill or knock off any that climb back aloft.

My last couple of sprays will be oil, which smothers protected mothers and crawlers. (I know this sounds brutal, but experience yourself a houseplant heavily infested with scale and the associated sticky, blackened carpet and furniture before passing judgement.) Oil can damage plants also, especially evergreens, so the oil to use is “horticultural” oil, also known as “summer” oil, which is highly refined to remove harmful ingredients. Like soaps, these oils are relatively nontoxic to nontarget organisms.

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Usually, scale insects hardly make their presence known until just after midwinter. I do notice a couple of scaly bumps on citrus and staghorn fern; these I deal with mano a mano, with a flick of my fingernail.

Strawberry guava, though, already has plenty of tufts of white cottony cushion scale on it. The guava also is loaded with ripening fruits so needs all the energy it can get, especially with shortening days. This tropical fruit tastes nothing like strawberry but has a sweet, perfume-y flavor with a nice tang. The reddish flesh and abundant, edible seeds probably give rise to the “strawberry” part of the name.