ROT AND FLOWERS
Brown Rot Strikes Again
The plan was for me to be now sinking my teeth into the soft, juicy, rich flesh of my Oullins golden gage plums. The tenuous start this past spring, with a freak late freeze that sent temperatures plummeting into the low teens, had me worried. The trees shook off the cold and, when warmer weather returned, burst into snowballs of white blossoms. Tiny fruitlets that followed those blossoms have swelled to the bountiful crop now dangling from the branches.
The plan has been foiled — by brown rot disease. Almost every plum, just as its skin starts to shade towards ripeness, becomes spotted with fuzzy, gray droplets that, with good weather (good for the fungus, that is), soon covers the fruit.
Brown rot was not unexpected, and a counterattack was planned. All through spring, before blossoms even unfolded, I doused the plant with insecticide and fungicide sprays. Insecticides help control brown rot by preventing insects, most notably plum curculios, from laying eggs in the developing fruitlets. Even if the egg-laying itself doesn’t cause the fruit to drop, holes left behind provide easy entrance for the brown rot fungus.
Perhaps I was too lenient, using relatively benign (to us humans, that is), organically approved sprays. ‘Surround’, a commercial formulation of kaolin clay for the insects. And sulfur, a naturally occurring mineral, for the brown rot fungus.
That’s not all. Gathering up infected fruits cuts back the number of new disease spores that waft among the branches looking for new fruits to infect. In fall and winter, those infected fruits are easily recognized as blackened, dry “mummies.” They lose their dryness and come to life, fungal life, with spring’s warmth and moisture. I’ll gather them up also. I’m hoping my ducks develop a taste for the fresh, dropped, rotten fruit; so far, they seem to be picky eaters.
My late winter pruning of the trees should also have helped reduce brown rot disease. Removing enough stems and limbs to allow those that remain to bathe in light and breezes allows for quicker drying from dew or rain.
The Disease Triangle
Three conditions must be satisfied for any disease, whether in animals or plants, to take hold: inoculum must be present, the host must be susceptible, and the conditions must be suitable for disease development. Check, check, check for my Oulin plum (a susceptible host plant) getting brown rot here in the Hudson Valley, throughout most of the humid eastern U.S., in fact. We have plenty of wild and cultivated plums and related plants here to provide brown rot inoculum from infected fruits, and the weather is usually just about perfect (for the disease, that is).
But Oullin isn’t the only great-tasting plum. How about a less susceptible host variety? Fungi are picky eaters, and varieties of plants vary in their susceptibility to specific diseases.(Unfortunately, most gage-type plums, which are heart-shaped, with greenish flesh, are very susceptible to brown rot.)
My plum trees are grafted to multiple varieties. The variety Shiro also finds a home on the tree grafted to Oullin. This year, and in years past, Shiro seems to be somewhat resistant to this disease. And I see that Cummins Nursery has a variety called Jam Session that also is resistant. This past spring I also planted the varieties Alderman and Superior, which are American hybrids with some alleged resistance.
As consolation, plums are, at least, less susceptible to this scourge than are peaches and apricots.
Flowers to the Rescue?
I’m planning and planting for flowers for next season and for years to come, with perennials.
I could, of course, just purchase some potted plants to plug into the ground now or next spring. I could buy seeds and sow them next spring. Instead of those two options, I’m sowing seeds now, a time when, admittedly, there’s not that frenzied urge to plant seeds as in spring.
One packet of seeds can — should — result in oodles of plants, plenty to plant and to give away. Sown now, the seeds should grow into plants that will be large enough to weather autumn, then winter’s, cold. Plants should also be large enough to flower next year. Their experience of cold, known as vernalization, will further coax them on to flower. Spring sown perennial flower seeds often don’t flower their first season, no matter what their size, because they have yet to be vernalized.
I’m sowing purple coneflower (Echinacea), black-eyed-susan (Rudbeckia), and blazing star (Liatris). They’re all in the daisy family, a family known not only for its good looks but also for providing nectar to attract and help support beneficial insects. If I plant enough, perhaps the increased number of beneficial insects will significantly decrease the number of plum curculios and other plum fruit insects resulting in, because of less insect scarring of fruit, significantly less brown rot of my plums.
It’s a stretch but the flowers, anyway, are very pretty.
PESTS, INCLUDING ME(?)
Watch Out, for Black Walnuts
Citizen scientists (that could be you and me), look up! At black walnut’s leaves. At the recent meeting of the New York Nut Growers Association (www.nynga.org), Karen Snover-Clift of Cornell University went over the ins and outs of “thousand cankers disease of walnut.”
Like Dutch elm disease — it pretty much wiped out American elms, once valued for creating a cathedral effect as their branches arched over tree-line streets — thousand cankers disease is spread by an insect. But the walnut twig beetle is only part of the problem. When it bores into the bark, it spreads a fungus that clogs up a tree’s “tubes.”
With Dutch elm disease, once a tree is infected, the fungal culprit spreads within the tree to kill it. Not so with thousand cankers disease. With this disease, death comes from fungal infection that follows thousands of dark, dead cankers of insect feeding.
Who cares about black walnuts? I do. Each fall the trees bear an abundance of nutritious and delicious nuts. (Not delicious to everyone; the strong flavor does not appeal to everyone. But no reason any food should appeal to everyone unless you’re MacDonald’s.) And, quoting from The Tree Book, written in 1914 by Julia Rogers, “The black walnut is majestic as a shade tree — a noble ornament to parks and pleasure grounds. It needs room and distance to show its luxuriant crown and stately trunk to advantage. Then no tree excels it.”
Walnut twig beetle
And finally, black walnut yields among the most beautiful of woods for furniture and gun stocks. Again quoting Ms. Rogers, the wood has “silvery grain, rich violet-purple tones in the brown heart wood [and] exquisite shading of its curly veinings.”
Thousand cankers disease moved into southwestern U.S. from Mexico (would a wall keep them out? will Mexico pay for it?) and has remained mostly in that region. Black walnut is native to eastern U.S., but the tree has occasionally been planted out west. More importantly, the disease has recently reared its ugly head at a few locations in the east. If infected trees can be identified, the disease can be contained to check its spread.
Thousand cankers
Any tree with an infected branch is usually dead by the end of the season!
So look up, scan the tops of any black walnut trees for limbs that are dead or show flagging foliage. Your job, and my job, is to look for these trees and then report them.
For a more thorough treatment of thousand cankers disease, as well as reporting guidelines, see www.thousandcankers.com. A good start in confirming the disease would be to take some good digital photos and send them to the state diagnostic laboratory, the county Cooperative Extension office, or department of environmental conservation.
Chipmunks, Still Cute Here
I find chipmunks cute, as I’m sure everybody would — except for anyone for whom chipmunk is a garden pest. This year, for some reason, an especially good crop of chipmunks are scurrying about. I see them everywhere, except on my farmden. Their absence here could be attributed to my dog friends Sammy and Scooter, and my cat friend Gracie.
I would not tolerate chipmunks if they were to eat my blueberries, my filbert nuts, my . . . pretty much anything I’ve painstakingly planted and nurtured. Besides dogs and cats, traps also are effective.
No, I’m Not a Strawberry Pest
As if plants didn’t have enough pest problems. I recently attacked my strawberry bed with my scythe, swinging the sharp blade low enough to cut off every last leaf from the plants. No, I’m not just another plant pest, trying to kill plants; I was “renovating” the bed, preparing it for next spring.
Shearing off the leaves not only removes leaves, but also disease spores on the leaves that inevitably find their way into any strawberry bed. Obviously, I raked up the old leaves and carted them over to the compost pile.
The next step in renovation was to pull out any weeds in the bed. The major weed in the bed was . . . strawberries. Strawberries spread by creeping stems along which grow new plants that take root, making them usually their own worst weed. Each plant needs about a square foot of elbow room to realize its full potential of one quart of berries per plant.
So I ruthlessly ripped out enough plants so that my 3-foot-wide bed was left with a double row of plants spaced a foot apart. Older plants get decrepit with age, so those were the first to go.
Finally, icing on the cake. I laid a 1 inch depth of compost all over the bed and tucked up to each of the remaining, leafless strawberry crowns. A little fertilizer and straw, pine needle, wood shavings, or any other weed-free organic material would be almost as good.
It’s been a few weeks and already new leaves are sprouting. The plants are on their way to a healthful and healthy crop of sweet, juicy berries next spring.
GOOD FRUITS, ONE A VEGETABLE
World’s Best Fruit?
Finally, I reap the fruits of one of my labors. Literally. The fruit is black mulberry, the species, that is Morus nigra, rather than any of the black-colored mulberries that grow all over the place around here. The latter are species and natural hybrids of white and red mulberries (M. alba and M. rubra).
Black mulberry, native to the Mediterranean climate of western Asia, is not cold-hardy below temperatures in the ‘teens (Fahrenheit) so definitely not cold-hardy here. I first tasted it at a fruit conference in Davis, California and it wowed me even from among bowls heaped high with fresh-picked apricots, peaches, and other seasonal fruits.
I had to get a tree to grow, which I did (from www.whitmanfarms.com). The tree went into a pot with potting soil. As it grew, I moved it on into larger and larger pots, stopping at an 18-inch diameter pot. I figured that would be the largest pot I could muscle down the basement steps for cool, winter storage along with my figs and pomegranates.
The tree bore quickly, and the “east coast” black mulberries were delicious, what few of them I harvested. Problem was that birds also found them delicious, a problem compounded by the fact that the berries are not at their best until matte black and ready to be released from the plant at the slightest touch. The birds don’t wait that long.
Dead ripe, the fruits are so soft that they can’t help but stain your fingers. (The stain was once used as a dye, called “murry.”)
A Cagey Solution
My first solution to the bird issue was to plant the mulberry in the ground in my cool (as in temperature cool) greenhouse, which is also home to some in-ground fig trees. Since mulberry seedlings pop up all over the place around here, I just dug up a seedling, grafted onto it a stem from my black mulberry, and planted it in the greenhouse.
Mulberry trees can grow big, bigger than my greenhouse. My plan was to espalier the branches against the west wall of the greenhouse. The espalier worked as far as training the branches in an ornamental candelabra. The birds were kept at bay. The espalier did not work as far as bearing fruit, the reason for which I have no idea why. I dug up the tree.
My original mulberry still grows in a pot and, despite its small stature, still bears good crops of fruit. A few weeks ago I saw advertised a walk-in, temporary cage for protecting plants from birds (available from Gardeners Supply Co.).
The cage arrived just as the first black mulberries were ripening. Within 20 minutes I had the various pole pieces joined to each other and to the corner brackets, and the net attached over the top and sides. At 4 feet by 4 feet and 6 feet high, the cage easily accommodates my mulberry. Even another plant or two.
Every couple of days, now, I unzip the door, enter mulberry paradise, and carefully peruse the plant for dead-ripe berries. I exit with purple-stained fingers. Success.
Eggplant + Oil, A Good Combo
Another success this year has been eggplant. I’ve gardened for many, many years, and for many, many years wasn’t able to grow eggplants well. Beginning gardeners are the ones who usually have greatest success with eggplant. Not exactly beginning gardeners, but beginning gardens.
Flea beetles love to eat eggplant (leaves). They pock the leaves with enough small holes so that only vigorously growing plants survive. But flea beetles rarely show up in a garden in its first year but by the second year they descend in hoards. Hence the successes of beginning gardeners in their beginning gardens.
This year I tried controlling the beetles by spraying the plants weekly with “horticultural oil,” also called “summer oil,” which is a more refined and lighter version of “dormant oil.” I was mixing it up anyway to keep scale insects at bay on the greenhouse figs (more on that some other time). Long story short: The plants are only slight hole-y and I have a fine crop of eggplants on the way.
