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Figs and Peppers and . . .

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Fig Frustrations and Joys

Over the years I’ve shared the joys and frustrations of growing figs in my minimally heated greenhouse. The joys, of course, have been in sinking my teeth into fruits of the various varieties. Also, more recently, the neat appearance of the plants which are trained as espaliers. Fig espalierLeft to its own devices, a fig can grow into a tangled mess. In part, that’s because fig trees can’t decide if they want to be small trees, with single or a few trunks, or large shrubs, with sprouts and side branches popping out all over the place.

A major frustration in my greenhouse fig journey has been insects, both scale insects and mealybugs. These pests never attack my potted figs which summer outdoors and winter indoors in my barely heated basement. In the greenhouse the problem each year became more and more severe, eventually rendering many of the ripe fruits inedible.More fig espaliers All that despite my attempts at control by going over plants with a toothbrush dipped in alcohol, oil sprays, and sticky barriers to keep ants, which “farm” these pests, from climbing up the trunks.

Scale and mealybugs are hard to control, let alone eradicate. Yet I am now secure enough in my victory to have claimed success in the battle.

Success began last year, when research pointed me to two predators of these pests, Chrysoperla rufilabris and Cryptolaemus montrouzieri, both of which I ordered online and released into the greenhouse. They were expensive, bringing the cost of my fresh figs to about one dollar each. Still worth it, though.

I got to thinking, “Perhaps I could perennialize these predators in the greenhouse so that additional annual purchases would be unnecessary.” As a first step to creating a home (or a jail, depending on your perspective) for them, I covered all greenhouse openings to the outdoors with window screening. These predators also like moisture, so I periodically spritzed the greenhouse and laid some absorbent wads of paper here and there on the branches.


I further thought, “How does the greenhouse environment differ from the great outdoors, where my figs are pest-free?” Rainfall! Although the greenhouse environment is humid, water never falls on the plants’ leaves and stems. So rather than period spritzing, almost every day since early spring I have blasted leaves, stems, and developing fruits with water.

The result: I haven’t seen one mealybug or scale insect all season!

Success, Who Knows Why?

I have to restrain myself from the usual gardener’s hubris in thinking that what I did cured the problem. Perhaps the “rainfall” favored the predators, of which there’s been nary a sign, by knocking the pest insects off the plant, or by creating a moist environment inimical to the pests, or . . .  Perhaps my screening the greenhouse cured the problem. Perhaps the pest problem disappeared for none of these reasons. Or from some combination of these reasons.

If I had a full-blown experimental station and was willing to sacrifice some fresh figs to science, I could possible sleuth out the answer with control plants to what happened. But I don’t, so I’ll just keep enjoying and be thankful for the fresh figs — and keep a close eye on what’s going on.

Dondé Está la Salsa?

I have a lot of faith in natural systems (aka Mother Nature), but sometimes she gets things mixed up. Case in point relates to peppers. The pepper crop this year is excellent, mostly because I staked each plant, weeded well, and grew varieties that do well here (Escamillo, Carmen, Perperoncini, and, best of all for flavor and production, Sweet Italia). 

What can be done with excess peppers? Salsa, of course. 

But a key ingredient for salsa is cilantro, which enjoys cool weather both for germination and growth. Self-seeded cilantro plants were sprouting and growing all over the place a few months ago. The dried stems topped by BB-sized seeds is all that remains of them. Cilantro seedsThose seeds will drop and germinate in the cooler temperature a few weeks hence. But I need cilantro now.

With foresight, I could have collected and sown these seeds a few weeks ago. The plants would have bolted (put energy into flowers rather than leaves) rather quickly but repeated sowings would have kept me in fresh new plants.

Belatedly, I have sown those seeds. To speed germination, I soaked them, then planted them in seed flats I kept in the refrigerator for a day and then moved to a cool, shaded area. Optimum temperatures for germination and growing of cilantro is 50-85° F. As I write, the temperature is in the mid-90s.
 

Fig Redux, One Week Later, A Bummer

Yes, mealybugs are still not to be seen. But now I see closely related scale insects. And plenty of them. Fig scaleSo I started the water sprays again, which have the potential problem of creating so much humidity and moisture that ripening figs rot. On the other hand, it might set back the scale, perhaps by knocking off ants, who “farm” scale. I also ordered a new predator, one for scale, Aphytis melinus.
 
Fig scale

THINGS NOT SO ROSEY

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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

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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.