MANURE ABSOLVED, PRUNING STARTED

Horse Manure: Not Guilty, So On To Pruning

    A dark cloud no longer hangs over my horse manure, that is, the horse manure that I occasionally truck over here to add to my compost piles. I wrote a few weeks ago about the possibility of herbicide that, when applied to hay, retains its toxic effect when an animal eats the hay and even, for a long time, after that animal’s manure has been composted or spread on the ground.
    My herbicide residue concerns were soothed with a simple assay that showed satisfactory growth from bean seeds in both hay that was suspect and hay of known integrity. Also, the bedding in the horse manure is mostly wood shavings rather than hay.
    But another ugly dragon kept raising its head above the manure. Another chemical, this time, Ivermectin, a de-worming medication given to horses (and other animals). Ivermectin or its metabolites might pass through the animal and injure soil dwelling creatures such as beneficial nematodes and earthworms. Past studies have shown negative effects on, for example, “dung fauna and degradation of faeces” (to quote a research paper from 2006).
    Ivermectin is, admittedly, a very useful material, even useful in humans to combat lice, bedbugs, and some more frightening tropical afflictions such as river blindness and elephantiasis. Agriculture is always a balancing act, but I like to keep my soil-dwelling partners happy.
    So I was gladdened when a veterinarian recently directed me to a Stanford University publication that summarized research findings on the environmental effects of Ivermectin. To whit: Ivermectin is excreted and it can affect earthworms, springtails, and other fauna. But it degrades quickly at summer temperatures (1-2 weeks, but much longer in winter) and within a day or two of exposure to bright sunlight. With temperatures within my compost bins reaching 150°F., or more, with the compost sitting many months before use, and with the compost being spread on top of the ground, little Ivermectin would end up in the soil. And soil anyway naturally has low levels of this compound.

Snow Makes Me Taller

    Let’s look aboveground, at stems; there’s pruning to be started. With well over a foot of snow on the ground, I turn my attention to taller plants. The snow is actually an advantage because, with snowshoes on, I can reach more than a foot higher into the branches without a ladder.

Sammy (the dog) and I pruning pawpaws

Sammy (the dog) and I pruning pawpaws

    For now, I’m going to start with the easiest pruning, mostly with plants that don’t need regular pruning beyond removing dead, diseased, broken, and grossly misplaced branches. Right here, such plants include pawpaws, plums, cornelian cherries, and a teenage honeylocust tree. Light is important for fruit production from the fruit trees and, generally, to keep diseases and insects at bay, so I also prune away enough branches to let remaining branches bathe in sunlight.
    I go at the pawpaws with one more goal in mind, to keep fruit from forming either too high in the tree or two far out on the limbs. Pawpaw trees will grow 15 to 25 feet high but I harvest fallen fruit from the ground. By my estimation, fruit can make a soft landing, undamaged, from a height of about 10 feet onto mulched ground. So I lop back the tops to weak side branches at about that height.
    Each pawpaw flower is a multiple ovary, potentially spawning up to nine fruits, each of which can weigh more than half a pound. That’s a lot of weight perched onto the end of a branch, so I shorten long branches to decrease leverage of that fruit load.
    (More about all types of pruning on all kinds of plants in my book, The Pruning Book.)

A Beautiful Climber

    I actually did begin pruning a few weeks ago, before the first snow fall. The plant was hydrangea — no, not the common bigleaf hydrangea which has many people scratching their heads about how to prune, but climbing hydrangea (Hydrangea anomala subsp. petiolaris).
 

Climbing hydrangea in summer

Climbing hydrangea in summer

   Climbing hydrangea is one of the most beautiful vines, even right now as the peeling, pale cinnamon, bark is in focus among the leafless stems. All summer long, the stems are clothed in lustrous green foliage and, in early, summer clusters of white flowers twinkle against that backdrop like stars in the dark sky.
    As expected, the vine took a few years to get firmly established. Now it threatens to engulf my brick home except that I want to restrict it to only the north wall. Every year now, I prune back stems creeping like groping fingers around the east and west walls. And each year the flower stems reach further directly out from the wall, so I also shortened them.

Climbing hydrangea, partially pruned

Climbing hydrangea, partially pruned

    The present pruning doesn’t permanently subdue the plant. This summer, I’ll again shorten the wandering stems, and I’ll be back at it again next winter and for winters to come.

FIRST SOWINGS OF THE YEAR, DEADLINE MISSED

 Onions & More, Late But They’ll Be Fine

   I missed my deadline by four days, sowing onion seeds on February 5th rather than the planned February 1st. That date isn’t fixed in stone but the important thing is to plant onions early.
    Onions are photoperiod sensitive, that is, they respond to daylength (actually, night length, but researchers originally thought the response was to light rather than darkness, so the phrase “daylength sensitive” stuck). Once days get long enough, sometime in June, leaf formation comes screeching to a halt and the plants put their energies into making bulbs. The more leaves before that begins, the bigger the bulbs.
    Plants from seeds sown outdoors — towards the end of March — won’t have as many leaves as plants given a jump start indoors. I like big bulbs; hence the early February sowing.

Fresh Seeds & Mini-furrows in a Plastic Tub

    First step on my way to onion-dom is to get fresh seeds. Onion seeds are relatively short lived and I want to give the plants plenty of time to grow. I don’t risk delays from poor germination and replanting of old seed.Onion seeds being sown in mini-furrows in pan of potting soil.
    Seeds get sown in a miniature “field:” A plastic tub 18 inches by 12 inches, with drainage holes drilled in its bottom and filled 4 inches deep with potting soil. Some weed seeds are unavoidably lurking in the garden soil and compost in my homemade potting mix, so I top the potting mix with a one inch depth of a weed free, 1:1 mix of peat moss and perlite.
    The edge of a board pressed into the firmed soil mix in the tub makes furrows, 6 of them equally spaced and about 1/2 inch deep within the tub. Into each furrow go onion seeds, sprinkled at the rate of about 7 seeds per inch. Once the furrows are closed in over the seeds, I water thoroughly and, to avoid washing away seeds, gently.
    Covered with a clear pane of glass and warmed to 70 to 75° F, the seeds should appear as grassy sprouts above the soil mix within a couple of weeks. From then on, my goal is to keep the plants happy with abundant light and water as needed. They get a haircut, their leaves snipped down to 4 inches, whenever they get too floppy. The compost and alfalfa meal in the potting mix should provide sufficient nourishment to the seedlings until they are ready for the great outdoors. That deadline is April 15th, weather permitting.

Other Cool Temperature Seeds Join the Party

    Onions won’t be alone on the seedling bench in the greenhouse. I’m also now sowing seeds of celery, celeriac, and leek. All, like onion, need a long period of growth before they’re ready for outdoors.
 

Onion seedlings, up and growing.

Onion seedlings, up and growing.

   These seeds get sown in furrows in small seed flats from which the seedlings, once they have two leaves, are gingerly lifted and cozied into waiting holes poked into the potting mix filling seed trays with individual cells. Little growing space is needed because a single seed flat can be home to a few kinds of seeds and the celled trays in which the seedlings grow until planted outdoors can house about two dozen plants in a square foot.
    I’m sowing lettuce in a similar manner. In contrast to celery and company, lettuce grows quickly. It’s needed to fill in gaps opened up from winter harvests of kale, lettuce, mâche, claytonia, celery, and parsley in the greenhouse, and should be ready to eat in April.

Nature & Nurture & the Spiciness of Onions

    Last year’s onions were abundant, large, sweet, and juicy. Anticipating their not keeping well, we ate them quickly, pulling the last ones from their hanging braid in the basement sometime in November. These were so-called European-type onions, varieties such as Ailsa Craig and Sweet Spanish.
    Next year we should have fresh onions for soups and stews on into winter because I’m growing some American-types, New York Early and Copra. American-type onions are actually sweeter than European-type onions, but their sweetness is masked by their increased pungency. That pungency comes from sulfur compounds, which are vaporized during cooking. Those sulfur compounds are also what help these onions keep longer.

Stored onions, in basement

Stored onions, in basement

    Soil enters the picture when it comes to onion flavor and storability. Sulfur is an essential plant nutrient and the more sulfur in the soil, within limits, the more sulfur in the onions. Sulfur is a key component of organic matter, so my compost-rich soil (with a whopping 15% organic matter) should have plenty of sulfur.
    Still, I’m thinking about spreading sulfur, the same pelletized sulfur I use to maintain soil acidity beneath my blueberry bushes, on half my onion beds to see if flavor or storagability are noticeably affected.

HOW TO FEED THE WORLD

Perennial Wheat to Save Our Soil, But What About Compost?

    We — that is, almost all of humanity — get all our sustenance from the thin skin that covers out planet, the soil. In appreciation of this, the United Nations has declared 2015 “The Year of Soil.” “Soil is more important than oil,” stated Wes Jackson, founder of the Land Institute, in his keynote at this year’s recent NOFA-NY  conference. Like oil, soil is a nonrenewable, or only slowly renewable, resource. Centuries go by before rainfall, freezing, thawing, and microbes and plants eat away at rocks to make new soil; on average, it takes a thousand years for the creation of a mere half-inch of new soil.
    The problem is that, as with oil, we humans are using up soil faster than new soil is being created — 10 to 40 times faster! Also, as with oil, that soil, as it is used, releases carbon dioxide and other greenhouse gases. Tillage exposes carbon stored in the ground to air, burning” it up, and annual crops, which are represented by sweeping fields of corn, soybeans, wheat, and other staples of civilization, put little of the carbon that they take in from air below ground. Agriculture is the second highest generator of greenhouse gases.
    Whew, what to do? Dr. Jackson’s tack, for the past half century, has been to focus on shifting our staples from annual to perennial crops. Wheat, for instance. Kanza, a hybrid, perennial wheat under development at the Land Institute, would sequester carbon by not requiring annual tillage and by packing carbon compounds into its long-lived root system. Perennial crops also decrease opportunities for soil erosion (another source of soil loss), grow with less added fertilizer and water,  and have the potential to increase biodiversity for a healthier ecosystem.

Organic Materials: Wasted Fertilizer

    What about vegetables, how are they treating our resources? Up to the podium stepped Tim Crews, director of research at the Land Institute, to give the roomful of organic and aspiring organic vegetable farmers and gardeners bad news: Our soil care is not sustainable. All that manure hauled onto our fields or piled high into compost piles is bedded with hay or comes from animals that have been fed grain. The grain or hay was grown in fields that were fertilized, most of it with commercial fertilizer which is mostly made from atmospheric nitrogen via the Haber-Bosch process which requires — you guessed it — fossil fuel for energy.Organic materials feed compost pile.
    Still, the fact that organic farming and gardening wastes less energy than conventional farming and gardening should assuage some of the guilt that resonated through the room. The soil of a good organic farmer or gardener will, in general, be higher in organic matter (5.4% vs. 3.5%) and, hence, carbon. Said plot will require less water, less pesticide, and less manufactured nitrogen for fertilizer.

Compost, Garden — and Small Farm — “Gold”

    Compost, and compost alone, is how I maintain fertility in my vegetable beds. I do haul in some horse manure for that compost, and, as Dr. Crews pointed out, somewhere way back in that manure’s history, fossil fuel needed to be burned.
    But civilization, and especially industrialized civilizations, generate many waste products, of which horse manure is one. Picture also all the food waste from restaurants and supermarkets, autumn leaves and grass clippings that are considered “garbage,” even sewage effluent. All these organic materials contain carbon, some of which could be sequestered in the ground, to the benefit of agriculture and the environment, and some of which feed soil organisms and, in turn, plants.
 Turning compost pile.   Better to recycle as much of those organic materials as possible into agriculture than let them go to waste or cause pollution. The bottlenecks here are cultural and political rather than agricultural.

Grow Your Own Fertilizer

    Another way, as I suggested at the conference, to make vegetable farming more sustainable would be to grow your own carbon and fertilizer. A perennial grain or hay field could be harvested for the grain or hay for the animals or, even more efficiently, just for hay to use either as mulch or for composting. Running hay or grain through animals burns up carbon to grow and fuel the animal to the tune of, on average, about 6 times more needed in terms of calories. That is, for every 6 calories we grow and feed to a cow, we get only one calorie back when we eat the cow.
    Left to its own devices, any field will naturally build fertility. Bacteria, free-living bacteria and symbiotic with the roots of legumes, harvest atmospheric nitrogen and put it in the ground, and the combined action of myriad soil organisms slowly chew away at a soil’s rocky matrix to release other nutrients for plant use. Plants grow, their roots oozing substances that further stimulate microbial activity and soil fertility.

Nodules from nitrogen-fixing bacteria on soybean roots.

Nodules from nitrogen-fixing bacteria on soybean roots.

    The key word in the previous paragraph is “slowly.” In order to be able to harvest fertilizer in the form of hay from a field year after year, sufficient time must be allowed between harvests for fertility to be garnered from the air and rocks. For that you need either more land or less harvest. The big picture, then, is to have more land, to make better choices in how the land is used, to utilize organic practices, and have fewer people.
    With the problems of soil improvement, global warming, sustainability, and agricultural production solved, I’m going to sow onion seeds. Planted in flats in potting soil at 7 seeds per inch, I should have plenty of pencil-thick seedlings ready to poke into holes in compost enriched beds in early May.

LECTURES THIS WEEKEND

Feb. 14, 2015
Gardener’s Supply Co.,Burlington, VT
Espalier Fruits
My Weedless Garden

Feb. 15, 2015
Northeast Organic Farming Association of VT, Winter Conference,
Burlington, VT
“Hardy Kiwifruits”
“Compost Tea: Snake Oil or Plant Elixir?”

LUSTING FOR AVOCADOS, HOME GROWN, OF COURSE

A Long Journey to Avocado-dom

This far north, an avocado plant provides reliable entertainment and, less reliably, the makings of guacamole. The entertainment doesn’t compare with the excitement of a car chase on the silver screen; it’s slower but very engaging.

To whit: I’ve been watching roots on two avocado pits elongate and branch. I spend a lot of time with plants; here is my opportunity to spend quality time with their roots. That’s all possible because avocado pits, suspended in water, will sprout roots whose growth can be watched.  (Odd, since wet soils are the nemesis of avocado trees planted outdoors in tropical and subtropical climates, and you can’t get much wetter than water.)Avocado sprouting in water

Despite being plants of warm climates, avocados are frequently raised by us northerners, as houseplants. I could have planted the pits in potting soil in a pot, but would have missed out on root entertainment. So I stuck three toothpicks into and spaced evenly around each pit so that the pits could be suspended in a beaker with their bottoms — their fatter ends — sitting in water. Taking a thin slice off the top and bottom of the seed, which I did, reputedly speeds germination.

Roots typically sprout before the tops show any sign of growth. 

Whoops, Things Don’t Look So Good

Avocado houseplants are so common that probably none of the above is new information to most readers. I’m embarrassed, then, to admit that my two plants have faltered in their growth.

One of them sent a sprout upwards after its roots were a couple of inches long. That sprout has dried out and, of course, ceased growth.

I noticed a slime surrounding the root of the other pit. This pit was very slow to sprout, and my guess is that there’s some bacteria attacking the weak growth.

I ascribe both failures to growing conditions which, here, indoors, are a far cry from the mostly warm, humid climes avocados call home. Mine sit near a window, experiencing wide swings in temperature in a room heated with a wood stove. Starting new plants in spring should bring better luck.

Entertained by Apical Dominance

I did get to effect and observe apical dominance on one of the plants. More benign than it sounds, apical dominance is the tendency for most vigorous growth from a plant’s uppermost buds, those either at the ends of branches or spatially at the highest points.

Avocado, roots branchingThat vigor comes from suppression of buds lower down by auxin, a plant hormone that is produced in the uppermost buds and transported down the stem. Lopping off the top of a stem stops hormone production (temporarily, until the new higher buds start making it) so lower buds grow as they let go of their inhibitions. 

The taproot growing from one of the avocado pits was threatening to bump into the bottom of the beaker so I pinched off a half inch of its tip. The effect was a mirror image to what happens with branches: within a few days, branch roots began to develop. Very entertaining.

An avocado sprout typically shows strong apical dominance, developing into a gawky plant with a single, upright shoot. Cutting the growing top back by a few inches induces branching and makes for a prettier plant.

Flowers, But No Fruit

More than beauty, I’d like fruit from my avocado plant. Under good conditions, such as in the ground in Florida, a pit would need 8 years or more before it became old enough to bear fruit. And then, said fruit might not be of best quality because the seedling would reflect whatever jumbling around of chromosomes occurred when the female flower that gave rise to the fruit that begot the seed got dusted with pollen from a male flower.

Blossoms on my potted avocado

For quicker bearing and more reliable good taste, cloning is needed, in this case grafting a branch from a tree known to bear good-tasting fruits onto the young seedling. Bearing, then, occurs within 3 or 4 years, and the fruit should be identical to the mother plant from which the stem for grafting was taken.

Not so fast, though. You need two varieties for cross-pollination, and avocado has some pollination quirks. Still, my plan is to get new pits sprouting, and once their stems are large enough to graft, to get scions for grafting. Years ago, I did all this and got flowers but no fruit. I’m hopeful, this time around, to be making guacamole within 6 years.

Outside Now, For More Apical Dominance

The time is drawing near for some real gardening, which could start with pruning. I’ll be putting apical dominance to work on some young fruit trees — each a mere “whip,” single, vertical stem — planted last year. Shortening the main stem will induce side branches that will eventually become the permanent scaffold limbs of these plants. The more severely any stem is shortened, the fewer and the more enthusiastic the sprouts from the buds lower down.