Fruit, Again, With Nod To Michael Jackson

Blackcaps Redux, This Season

I took a cue from Michael Jackson today when pruning my black raspberry (a.k.a. blackcap) plants. Not that I had to prune them today, or even this time of year. But I couldn’t stand looking at the tangled mass of thorny canes. And, more importantly, the tangled mass would make harvest, slated to begin in a couple of weeks or so, a bloody nightmare.

(Most blackcaps bear only once a year, in early summer, so tidiness would be the main reason to prune conventional blackcaps now. Pruning would also let remaining canes bathe in more light and air, reducing the threat of diseases. My blackcap plants, though, are the two varieties — Niwot and Ohio’s Treasure — that bear twice a year; hence, my pruning now to make picking the soon-to-ripen second crop less intimidating.)

All blackcaps have perennial roots and biennial canes. Typically, the canes just grow their first year, flower and fruit their second year, then die. Niwot and Ohio’s Treasure differ in bearing on both one-year-old canes and on new canes. I picked the early summer crop from canes that grew last year. And now my mouth is watering as I look forward to the late summer crop, which will be borne on canes that just started growing this season.
Pruned blackcaps
Pruning is straightforward. I started by lopping right to ground level all the canes that bore the early summer crop; they’re dying anyway. Step two is reducing the number of new canes, selectively keeping the fattest and healthiest-looking ones, and lopping all others to ground level. Even then, I reduce their number to the best six of them. That’s it. Easy, as long as the thorns are avoided.

My blackcaps are in a row, three feet apart. An iron pipe sunk into the ground next to each plant provides support for each plant’s clump of stems. With pruning finished, I tied a piece of rope to the pipe and then around the clump of stems, a gloved hand cozying the thorny stems into position while my ungloved hand tied the rope, à la Michael Jackson.Tying blackcap with gloved hand

Rotten Plums

I wish that pruning was all that my plum trees needed. With this being such a good year for fruits generally, I was very hopeful for a good crop. And they looked fine up until a week ago, when the fruit started ripening — and rotting.

Brown rot is the culprit, mostly the handiwork of the fungus Monolinia fruticola. Characteristic powdery, gray masses of spores form on the surfaces of rotting fruits, which eventually dry to become “mummies.” Brown rot is not new to me; I’ve experienced it on peaches, nectarines, and plums in the past. It also attacks apricots, cherries, and other “stone fruits” (Prunus genus). Typically, a plant bears well for a couple of years while the fungi are building up, and then full-fledged, annual attacks begin.Brown rot

The usual recommendation to hold the fungus at bay is, first, to remove sources of inoculum by cleaning up all infected fruit in summer and mummies in winter, and pruning away dead, infected twigs. That’s quite a job on a big plum tree.

I sprayed my trees with sulfur many times this past spring. Sulfur is an organically approved fungicide, used by gardeners and farmers for thousands of years, that is effective against brown rot. But only for a few days. Hence my repeated sprays, evidently not repeated enough.

The easiest approach would be for me to grow brown rot resistant varieties.

Plumquest Begins

So now I am embarking on a plumquest, my search for plums that taste good and are resistant to brown rot. Resistant genes must lurk somewhere — actually right in my yard, on the wild plums. They hardly ever show fuzzy grayness; they also don’t taste very good.

I now remember a pertinent page I photocopied many years ago. Shuffling through piles of papers on my desk, I come across the page, from a scientific-looking paper, entitled “Range of known genetic traits in Plum cultivars.” That’s a start, and the list on the page includes one of my favorite plums, the Green Gage, also known as Reine Claude Verte, as resistant. Shiro, which I grow with some success, is only listed as “tolerant.”

My next queststep is on the web, bringing me to a publication entitled “The Cultivated Native Plums and Cherries,” authored by Liberty Hyde Bailey in 1892. I immediately ordered a reprint to make it easier to sort through the many varieties and their gustatory and pest potentials.

Once suitable varieties are identified, the next queststep is to locate trees or, more likely, stems for grafting, to bring here to the farmden. I will report on my plumquest as events unfold.


Dry Soil

    Digging a hole to bury an animal last week gave me new respect for the plant world. Each shovelful brought up dusty, light brown soil, even to a depth of more than two feet. That’s expected, since it hasn’t rained more than 1/4 of an inch here for the past five weeks.
    With their leaves flagging in midday, trees and shrubs don’t exactly look spry. Still, they are alive, even some spring-planted trees and shrubs which have had little time to spread their roots deep and wide.

Thirsty, young Asian persimmon

Thirsty, young Asian persimmon

    Appearance of a soil can be deceiving. There’s some water lurking within those pores, water held tightly by capillary attraction. After heavy rains or irrigation, all soil pores get filled with water, a situation as bad for plants, if it lasts too long, as dry soil. Plant roots need air as well as moisture; air gets sucked in once gravity drains water from the largest soil pores.
    From then on, capillary attraction is what holds moisture in the ground — a pleasant situation for plants because the roots can tap into the more loosely held capillary water while they breathe freely. I prepare for possible droughts when planting by digging relatively small planting holes, which minimizes the amount of ground loosened up, in turn, among other benefits, preserving capillary networks in the soil. (Mulching and watering, right after planting, also helps.)
    Eventually, more and more of the loosely held capillary moisture gets sucked out of the ground by plants and evaporation. At some point, there’s still moisture in the soil, but what’s left is in the smallest pores and right against soil particles. It’s tightly held capillary moisture, water that plants can’t access. They wilt. When moisture levels drop to what’s known as the “permanent wilting point,” plants die.
    We’re not there yet and now, toward the end of the season, woody plants do have a Plan B: They can just drop their leaves, reducing moisture loss from stems and roots, and segue into winter on stored energy and moisture. To a point.

Cold Air

    If it’s not one thing, weather-wise, it’s another. On September 26th, I woke to find parts of the lawn hoary with frost. I’m not complaining. Frost should be expected, on average, around that date around here. Except that I’ve been spoiled for the last few years by much later frosts, frosts, so late that I pulled out old tomato plants because chilly weather drained tomatoes of their flavor rather than frosty weather killing the plants.Endive, lettuce, and old tomato plants
    Also, no complaints because the September 26th brought only a light frost; temperatures just hit 32°F. and the hoariness was spotty, here and there. A light frost is a good thing this time of year. It signals plants to get ready for even colder weather. In preparing for cold, cell walls strengthen and permeability of cells to water is actively altered. Even subtropical plants like peppers and tomatoes toughen up, with some chilly preparation, so that they can now tolerate temperatures that drop even a few degrees below freezing.
    Tender vegetables, frost or no frost, on the wane, have left the door open to vegetables that enjoy the cool weather of autumn. Most of the garden now presents a verdant sight of beds lush with lettuce, Chinese cabbages, winter radishes, endive, turnips, cabbages, arugula, mustard greens, carrot tops, and leeks, all ready for harvest, at my leisure, over the next few weeks.

Fall Black Raspberries

    Segueing over to the fruit world, I’m still harvesting the last of the blackcaps (black raspberries) of the season. Blackcaps? Anyone familiar with this fruit, abundant in the wild and often cultivated, knows that they ripen in midsummer.

Niwot blackcap, now ripe

Niwot blackcap, now ripe

    Last year I planted two new varieties of blackcap, Niwot and Ohio’s Treasure. With most blackcaps, canes just grow their first year, then fruit their second year. (During the second year, new canes are also growing, to fruit the following year, so a planting bears fruit every year.) Niwot and Ohio’s Treasure bear fruit at the end of the canes’ first year of growth, in late summer and autumn. Those same canes — I think — then continue bearing the following year, in summer, just like most blackcaps.
    I haven’t yet decided whether Ohio’s Treasure or Niwot offer the better berry, but it’s nice to be harvesting fresh berries this late in the season.