Horse Hooey in the Garden
Never use horse manure without composting it first
The proliferation of horse farms in southern Maryland has resulted in owners convincing their friends and neighbors that horse manure is great for the garden. After one experience with using horse manure in the garden, you’ll discover that it’s not what it’s cracked up to be.
Unlike cow, llama, alpaca, chicken or pig manure, which can be incorporated into the garden as soon as it drops to the ground, horse manure must first be composted. A horse is not as thorough in digesting the grasses, hay and grains that it eats as are other farm animals. As a result, horse manure contains high levels of carbon in the form of undigested hay and grain hulls, with many of the seeds still viable. In other words, those horse buns are loaded with weed seeds.
Don’t Take Peat Pots for Granted
Many bedding plants are grown in peat pots. The pots are biodegradable, but they can cause problems when planted incorrectly. If the outside of the peat pot is crusty hard and there are no roots protruding, it is best to tear away the peat before planting. If there are roots protruding from the walls of the pot, tear away the top edge so the remaining pot will be completely buried. Allowing the top edge of a peat pot to protrude above the soil will cause water to be wicked from the root ball, causing the plant to die of drought.
If you place uncomposted horse manure in your garden, you will be infesting your soil not only with weed seeds but also with hay or straw. If the horse manure was mixed with sawdust or wood shavings, you will be making matters even worse. The carbon from the sawdust, wood and undigested food will cause nutrient deficiencies in the plants you grow.
Hay, sawdust, wood shavings and grain hulls are all sources of carbon and must be decomposed before they can safely be added to soils. The decomposition of carbonaceous materials by microorganisms occurs during composting. The more sawdust or wood mixed with the horse manure, the longer it takes to compost.
And composting horse manure requires more than just putting it on the pile. You’ll need to turn the compost at least once a month and keep it moist, or it will stagnate. Do it right and the composting process generates heat that will kill any weed seeds and break down the carbon in the horse buns.
Horse manure compost is ready to use in the garden only when nothing is recognizable. The compost should have a rich dark color, a crumbly texture and an earthy odor.
Ask Dr. Gouin your questions at firstname.lastname@example.org. All questions will appear in Bay Weekly. Please include your name and address.