Thomas Christopher | Be-A-Better Gardener: Get the scoop on garden manures
Editor's Note: While garden columnist Ron Kujawski hibernates for the winter, columnist Thomas Christopher will be stepping in for bi-monthly garden advice. The column, which previously ran in Berkshires Week & Shires of Vermont during the summer, is in partnership with the Berkshire Botanical Garden.
This may sound like a strange recipe for bliss, but I am surrounded by animal manures. Good ones, I hasten to add.
I trust that the experienced gardeners among our readers will understand my enthusiasm. Properly handled, there is no food better for the garden than manure. It can also act as a soil conditioner, too, helping to aerate the soil by building structure. Best of all, it's free. In fact, the producers (or at least the harvesters) are, typically, relieved to see me haul it away.
Fall is the season when I focus on this task. The cooler weather helps to minimize the odor of the raw material — though I generally avoid the strongest smelling manures and content myself with collecting those that aren't odiferous. That's one reason I prefer horse to cow manure, that and the fact that horse manure is less sloppy to handle. I also like to use the manure from our coop full of pet chickens. The mixture of chopped straw bedding and poultry manure is easily moved with a manure fork or shovel, offers an intrinsic balance of nitrogen and carbon-rich materials ideal for composting, and hardly smells at all. Sheep or goat manure is supposed to be rich in plant nutrients, but I have never had access to either.
In any case, what you want is manure from plant-eating animals. The manures of carnivorous animals, such as dogs or cats, can contain dangerous parasites and should be disposed of with your garbage. In fact, any manure you use in your garden should first be composted, stacked in some inconspicuous spot and allowed to decompose. This will eliminate its smell and the yuck factor in handling it. It will also leave the manure in a state where its nutrients are safely accessible to your plants; fresh manure can be so rich in salts, so "hot," that it poisons your plants. Besides, fresh manures may contain large amounts of weed seeds; the composting process should kill most or all of these. So stack your manure now, mixing it with some carbon-rich material, such as fall leaves if it's very wet and fresh, and it will be ready to spread on the garden come spring.
Of course, you may think this advice isn't applicable to you. Perhaps you don't live in the country. Maybe you live in a town or a suburban area and think that, therefore, there isn't any source of manure close by. Nonsense! Even when I was a horticultural student at the New York Botanical Garden and I lived and worked in the Bronx, I found sources of suitable manures. There was a riding stable at the edge of a park not too far away, and right across the street, there was a bonanza: the Bronx Zoo. One of my instructors, in fact, heated a small greenhouse one winter by snaking an air duct back and forth through a heap of elephant manure and installing an intake fan at the end to harvest air warmed by its passage through the steaming heap.
Likewise, when I lived in suburban College Station, Texas, I used to drive out to a nearby mushroom farm to collect pick-up truckloads of spent mushroom compost, a mixture consisting largely of composted horse and poultry manure.
In short, I have found that enterprising gardeners can always find some source of manure not too far from their plot.
The nutritional value of the manure you collect will, naturally, vary with the type of animal and its diet. As a rule, its NPK (nitrogen/phosphorus/potassium) content will be modest by comparison with most bagged, synthetic fertilizers. Rabbit manure, for example, one of the richest, averages just 2.4 - 1.4 - 0.6 percent NPK by weight. But that's all to the good. Your composted manure won't deliver the kind of megadose of nutrients that upsets soil ecology. Instead, it offers your plants a modest, slow feed, just the kind they respond to best.
Be-a-Better-Gardener is a community service of Berkshire Botanical Garden, one of the nation's oldest botanical gardens in Stockbridge. Thomas Christopher is the co-author of "Garden Revolution" (Timber press, 2016) and is a volunteer at Berkshire Botanical Garden. berkshirebotanical.org.
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