BEAUTIFUL DESIGN AND UGLY BLIGHT
Who Made This Garden?
I visited a most beautiful garden this week, one in which all the elements of garden design were deftly combined. At ground level groundcovers presented pleasing and harmonious shades of green and varying leaf textures. Leafy plants, lichens, and mosses all contributed to the symphony, the whole scene knit together by large slabs of underlying rock.
In places, low-growing junipers and deciduous shrubs and trees brought the garden up from ground level. Particularly striking was a very large boulder atop of which grew some trees whose exposed roots embraced the boulder before reaching to the ground for water and nourishment. Green moss growing on the boulder erased any starkness from this vignette.
Shakkei, or “borrowed scenery,” an important element in Japanese garden design, played an important role. Distant mountain peaks created a dramatic backdrop in some views.
This garden also utilized what I like to call “luscious landscaping,” that is, the incorporation of dual purpose plants -– for beauty and for eating -– into the landscape. Lowbush blueberry, a plant whose dainty flowers hang like white bells in spring, whose healthy, green foliage ignites in crimson come fall, and whose stems glow red in winter, formed the bulk of the groundcover species. A few lingonberry plants interspersed here and there promised red berries in autumn and evergreen leaves as a foil for those red blueberry stems in winter.
And just where was this wonderful garden? Or gardens, I should say. They were in the high peaks of New York’s Adirondack mountains. The garden designer? God or one described by Darwin, take your pick. Beautiful, at any rate.
Blight Here in the Valley
Back down here on the flatlands, the word “blight” is often bantered around in connection with tomatoes this time of year – your tomatoes, my tomatoes, basically, everybody’s tomatoes! A few years ago, it was late blight (Phytophthera infestans) that was the blight that was of special interest. Attacking both tomatoes and potatoes, this is the same disease that caused the potato famine in Ireland in the 19th century.
Late blight was a problem in the northeast that year due to a particular confluence of events: infected tomato plants offered at “big box” stores gave the blight its start and rainy, humid conditions kept it going.
A few years ago; not this year.
The disease does not overwinter here in the north, except on infected potato tubers stored or left in the ground through winter. The way late blight arrives in the north is either on infected transplants or by hitchhiking up from southern fields, where it does overwinter, when weather conditions are just right. The spores can travel about 15 miles at a shot with the right winds coupled with cool, moist weather.
My tomato plants had their usual midsummer splotches and yellowing that year. I usually find pest problems more interesting than scary, I got a little worried about late blight. I tested for it by pulling a splotchy leaf off a plant, sliding it into a plastic bag, and waiting a day. White, fuzzy growth on the leaf would mean late blight. Testing was negative, although blight did eventually show up.
Only under the most severe conditions will I take special measures to control late blight. That year presented those conditions. I decided to spray my tomato plants, a measure to which I’d never before resorted. And it’s not because I grow mostly heirloom tomatoes; pretty much any and every tomato variety is susceptible to late blight. I used one of many copper sprays that are organically approved, still taking care not to dowse nearby other plants and to thoroughly protect myself while spraying.
Blight. What’s That?
That’s not to say all my tomato plants are the pictures of health this year, or any year. They do get some leaf yellowing and loss due to disease. Three diseases, in fact. One is the already mentioned late blight. The other two, which do rear their ugly heads reliably every year, are early blight and septoria leaf spot.
If you look closely at the leaf damage, you can tell which one(s) your tomatoes are hosting. Early blight (Alternaria solani), the most common of the three, marks leaves with dark-brown, round spots a half-inch in diameter, each surrounded by concentric rings.
Early blight
Septoria leaf spot (Septoria lycopsersici) causes spots that are small, round and gray, each surrounded by a single, dark margin.
Septoria leaf spot
And late blight causes greenish-black splotches.
Late blight
The names of any one of the leaf spot diseases is enough to conjure up fear of plague, but fortunately, all three can be lumped together when it comes to control. The first line of defense against any of the leaf-spot diseases is to keep disease spores away from tomato plants. Spores spend the winter in old plant debris, then are awakened and splashed onto new tomato leaves by rain during the growing season. Early blight and septoria spend the winter in old tomato refuse on the ground. Potato tubers can overwinter this far north on stored potato tubers that are planted out for the next season.
All of which makes a good case for a thorough garden cleanup each fall. At the end of the season I load up my garden cart and haul over to the compost pile old tomato and potato stems, leaves, and fruits.
During the growing season, any mulch — my choice is compost — keeps raindrops from splashing spores up onto plant leaves. Removing infected leaves during the growing season may also help control disease spread. I leave leaves intact, figuring more photosynthesis makes for stronger plants (except, of course, for any leaves too far gone to make a significant contribution to the plant).
Crop rotation each year moves tomato plants away from any spores left from the previous season’s crop. Plant tomatoes in a new location in the garden each year, never returning them to the same spot until four years have elapsed — admittedly a tall order in a small garden.
Another line of defense against leaf spot diseases, many diseases for that matter, is to create an environment inhospitable to them. Fungi thrive in dark, moist, humid places. Let plants bask in full sun without obstructions such as weeds, fences, or other garden plants that would slow air circulation.
I train each tomato plant to a single stem, which is staked, putting distance between the leaves and any spores on the soil, and exposing the plant to better air circulation. Spaced 18 inches apart, the plants yield less per plant than tomato plants allowed to run wild, but because they utilize a third dimension — up — more tomatoes per land area. Also earlier and with bigger fruits.
MORE THAN JUST PEACHES AND PLUMS HERE
Preiselbeere, Kokemomo, Puolukka, Partridgeberry, Cowberry, Rock cranberry — or Lingonberry, They’re All the Same Fruit.
Besides enjoying the season’s plums and peaches, I’m also enjoying a few uncommon fruits. Uncommon now. These fruits have been enjoyed by humans somewhere at sometime, just not extensively now.
The most familiar of these to most would be lingonberries (Vaccinium vitis-ideae). As jam, in jars, that is, unless you’re Scandinavian, where this fruit is very popular harvested from the wild and then used in drinks, sauces, and pancakes.
Lingonberry, which is native throughout colder regions of the northern hemisphere, is often compared with our native cranberry. I think that does lingonberry an injustice. Both are diminutive plants, spreading as their stems root where they touch the ground, so could be edible groundcovers. Both are evergreen, but while lingonberry’s dainty leaves have the same green gloss as those of holly, and retain it all winter, cranberry leaves turn a muddy purple with the onset of cold weather in late fall.
I recently read that the berries are “not good to eat in their raw state as they are quite bitter.” That writer evidently never tasted lingonberries; I eat them raw all the time and find them delicious. And it’s not because my taste buds are so robust. I’d never pop a cranberry, which is closely related to lingonberry, into my mouth. Too, too sour.
Lingonberry is now ripening fruits — and it’s also blossoming! The plants bloom twice each season, yielding an early and a later crop. 
If not harvested, the later crop hangs, looking pretty and in good condition for eating, through autumn and on into winter.
To thrive, the plant needs similar conditions to those enjoyed by blueberry, cranberry, mountain laurel, rhododendron, and other lingonberry relatives. In addition to good drainage and abundant humus, the soil needs to be very acidic, with a pH ideally between 4.5 and 5.5.
Right after planting and then each year thereafter, some time between fall and spring, my lingonberries get mulched with a one- to two-inch depth of some finely divided, organic material that is not too rich in nutrients: sawdust, woodchips, chopped straw, or shredded leaves, for example. The mulch sifts down through the leaves and stems to keep the ground cool and moist, prevent frost from heaving plants in winter, and decompose to maintain high humus levels in the soil — all of which translates to larger berries and more of them.
The plants require little care beyond regular watering for the first couple of seasons.
Centuries of Flavor
Also ripe now is a fruit that has been enjoyed by humankind for the past seven thousand years (although not so much now)! At a site in northern Greece, early Neolithic peoples left traces of their meals of cornelian cherry (Cornus mas), along with remains of einkorn wheat, barley, lentils, and peas. It was also well-known to the ancient Greeks and Romans. The hard wood was reputedly the wood for chariot axles.
The plant was grown in monastery gardens of continental Europe through the Middle Ages and was introduced to Britain about the sixteenth century. By the eighteenth century, the plant was common in English gardens, where it was grown for its fruits which sometimes were called cornel plums.
The fruit was familiar enough to be found in European markets even up to the end of the nineteenth century. Cornelian cherries were especially popular in France and Germany, and the fruit reputedly was a favorite with children.
Native to regions of eastern Europe and western Asia, the cornelian cherry is still appreciated for its fruit in certain parts of these regions. Baskets of kizilcik, as the Turks call the fruit, are found in markets of Istanbul. The fruit is a popular backyard tree in gardens of Moldavia, Caucasia, Crimea, and the Ukraine.
When the fruit was popular in Britain, it was made into delicious tarts, and shops commonly sold rob de cornis, a thickened, sweet syrup of cornelian cherry fruits. The juice also added pizazz to cider and perry.
Depending on ripeness, fruit flavor varies from sweet to tart. It has a distinctive flavor and can be used in cookery at all stages. If tart fruit is allowed to sit for a day or two or three, the flavor becomes less tart and more mellow.
Cornelian cherry is a favored ingredient of Turkish serbert, a fruit drink sold in stores and from portable containers carried like knapsacks on the backs of street vendors. In the Ukraine, cornelian cherries are juiced, then bottled commercially into soft drinks. There, the fruits also are made into conserves, fermented into wine, distilled into a liqueur, and dried.
The plant is actually not a true cherry, but a species of dogwood. It is still widely, but mostly planted as an ornamental for its very early show of small, yellow blossoms, around the first day of spring here on the farmden.
Cornelian cherry is among my most successful fruit crops. Despite its early bloom, it has never failed to bear. Birds, insects, and diseases have little effect on production. Pruning is unnecessary. What else can you ask for from a fruit plant?
(I am still looking for some good recipes that use this fruit and lingonberry for possible inclusion in an update of my book Uncommon Fruits for Every Garden. Got something? Both fruits are covered in my currently available books, Landscaping with Fruit and Grow Fruit Naturally.)
Intoxicatingly Delicious?
This last fruit is very uncommon, and I didn’t plant the tree mostly for its fruit. Hackberry (Celtis occidentalis) bark is gray with corky ridges that, especially in winter when illuminated by low-hanging sunlight, has that crisp, achromatic quality of photographs of the lunar landscape.
Hackberry bark
The fruit itself is refreshingly sweet, like a date. Problem is that the fruit is pea sized and contains an almost-pea-sized seed. So the fruits nothing more than a thin covering over the seed.
More prominent in the human diet is a close relative, one name of which is the lote tree (C. australis), which even figure in Greek mythology. When Zeuss drove Odysseus’ ships off course, the sailors finally found refuge in the Island of the Lote Eaters. Eating the fruits caused a pleasant drowsiness, to the extent that the sailors, forgetting their homes and friends, wished for nothing more than idling away on the island. Odysseus had to drag them back onto their ships.
The lote tree, native to Europe and temperate regions of Asia, is pretty cold-hardy (Zone 5). I have ordered seeds and should get to taste fruit of the lote tree in a few years. I might never leave the farmden.
COVER CROP CONFUSION
How Much Soil Organic Matter?
In last week’s blog I kept jumping the fence about cover crops. First I extolled their benefits. Then I wrote that they’re probably unnecessary in my heavily composted ground and possibly to blame for poor growth of some corn and tomatoes. Finally, I wound up stating that I do grow some cover crops anyway. No wonder I caused some confusion.
All this prompted one reader, Peter, to comment with some specific questions that might also be of interest to some of you. I will now try to answer them.
His first question was: “How is percentage of organic matter in the soil determined.” “Organic matter” is carbon compounds; as such they can be oxidized, and when this happens they are lost from the soil as carbon dioxide and water. Microorganisms do this naturally in any soil as they feed on organic matter, in so doing releasing minerals associated with the organic matter in forms that plants can use for nourishment.
The way to test the percentage of organic matter in the soil is to weigh a sample, oxidize the organic matter, then weigh it again to measure the loss. Oxidation can be done by burning the sample at high temperature. Another way is to chemically oxidize a weighed sample using potassium dichromate and then measure how much dichromate is left after the reaction. (The latter reaction is more accurate than burning because carbonates in a soil will also lose carbon dioxide when heated, affecting the final weight.)
Peter, I suggest against determining the percentage organic matter of your soil in your kitchen. Soil labs generally include percentage organic matter along with other test results. (I cover soil testing in my book Weedless Gardening.)
Peter also reported that his soil tests very high in phosphorus, potassium, magnesium, and calcium. Soils to which have been added lots of organic matter typically test very high or excessive levels of phosphorus and potassium. That doesn’t present a problem, possibly because, as I wrote last week, “Conventional soil tests are for mineral soils, not soils that are very high in organic matter.”
As far as the high levels of calcium and magnesium, I’m not sure about that. Excessive applications of dolomitic limestone would cause that, and that would also be reflected in a high pH.
To Cover Crop or Not to Cover Crop, That is the Question
Now for a more difficult question. Why do I plant cover crops if I don’t think they’re of benefit in my soil? I guess that’s because I’m aware of the known benefits of cover crops. If nothing else, the cover crop obviously protects the ground’s surface from the pounding of raindrops and wide swings in temperature. Even if I don’t notice any positive impact, they may be there, more subtly. And then there are the still unknown benefits of cover crops.
The major, consistent negative impact of my late summer of fall planted oat cover crops has been to increase the number of weeds the following spring, specifically henbit (Lamium amplexicaule). For the past couple of years I’ve dealt with that problem by tarping those beds in spring for a couple of weeks or more. Or, not as good, just pulling out the henbit.
Because I only cover crop beds that are no longer needed for vegetable plants towards the end of the growing season, growing the cover crops doesn’t take up space in which I could otherwise grow vegetables.
Buckwheat cover crop in greenhouse
It’s also almost no trouble to sprinkle the oat seed over the bed before laying down the inch of compost each bed gets every year.
And finally, I have to admit that I like the lush green look of the oat leaves, the leaves maintaining that look almost until the first day of winter. And even after that, they flop down on the ground, dying, but then hiding the brown compost beneath a tawny blanket.
Rye cover crop at Chanticleer Garden
Timely Planting
Last question: “When is the latest time to plant the cover crop?” Cooler weather and diminishing sunlight dramatically slow plant growth in autumn. Oats like that cool weather, and will germinate and sprout pretty late in the season. But there comes a time when so little growth will ensue that oats or any other cover crop is not really worth planting.
Here, about half way up New York’s Hudson Valley (USDA Hardiness Zone 5), I figure on the latest date to make planting a cover crop worthwhile is about October 1st.
