The Basics of Pit (or Trench) Composting
If you live in a place where digging holes in the ground is no big deal, you can make a pit compost. The following info helps you add anaerobic composting to your repertoire. Good choices for your pit compost include areas where you want to add a future garden bed or between rows of existing garden beds. Avoid marshy areas or low spots with wet soil or poor drainage.
Stay away from existing root systems when digging composting holes. Tree and shrub roots easily expand to twice the diameter of their aboveground canopy! Slicing through roots with a shovel creates easy wounds for pests and diseases to enter, ultimately weakening and possibly killing your plant. If you're unsure how far roots may have spread, stick to digging compost trenches in garden beds.
Depending upon what you want to achieve, you can employ several different methods of pit or trench composting, such as digging random holes, filling trench rows in garden beds, or rotating trenches over a three-year period to improve an expanded planting area. Use the basic anaerobic trench compost recipe that follows for whichever method you choose.
How deep and wide to dig depends on how much organic matter you have to compost, what kind of material it is (landscape waste versus kitchen waste), how easy it is to dig, and whether digging pests might be an issue.
Follow these steps to create a pit compost.
Dig the hole or trench, reserving the soil that you remove.
Start with browns on the bottom, alternate layers of brown and green materials, moistening as you build.
Spread a 1-inch (2.5-centimeter) layer of your reserved soil between layers of browns and greens.
Cover with 4 to 8 inches (10 to 20 centimeters) of soil. If you plan to retrieve the compost later, mark the area with a stone or other reminder.
If you grow flowers, herbs, or vegetables in straight rows with plenty of space between them, dig and fill composting trenches between the rows. As the organic matter in the trenches decomposes, nutrients become available for nearby plants. Dig trenches early in the planting season before vigorous roots expand into the area. Alternatively, dig trenches at the end of your growing season, so material is decomposed by the next planting season.
Certain plants really thrive on soil that's rich in organic matter and water-holding material, particularly sweet peas, runner beans, zucchini, pumpkins, and squash.
Six to eight months before planting, dig a trench or pit where you plan to grow these crops, 18 inches (45 centimeters) deep. Fill with kitchen waste, newspaper, manure, and other retentive materials, then top with a 6-inch (15-centimeter) layer of soil, heaping it up to form a mound. By the time your planting season rolls around, the site will have settled and will be ready for seeds or transplants.
Gardening Glossary
annuals
Plants that complete their entire life cycle within one growing season. The plant germinates from seed, grows and blooms, and then produces seed and dies.
Gardening Glossary
biennials
A plant that take two growing seasons to complete its life cycle. It germinates and grows leaves and stems in the first year; produces flowers and fruit (seed) in the second, and then dies.
Gardening Glossary
bolt
When a plant flowers or produces seed prematurely.
Gardening Glossary
cold frame
A wooden or concrete block box in which you can grow plants or hold dormant during the cold winter months.
Gardening Glossary
cole crops
A family of vegetables, including broccoli, cabbage, cauliflower, kale, and Brussels sprouts. They thrive in cooler weather.
Gardening Glossary
complete fertilizer
Any fertilizer that contains all three of the primary nutrients, N-P-K (nitrogen, phosphorus, potassium). Phrase is based on regulations governing the fertilizer industry. Does not mean that the fertilizer literally contains everything a plant needs to thrive.
Gardening Glossary
deadheading
The practice of pinching or cutting off spent flowers
Gardening Glossary
evaporative-pad humidifier
A humidifier in which fans blow across a moisture-laden pad that sits in a reservoir of water.
Gardening Glossary
harden off
The process of acclimating plants grown indoors gradually to the brighter light and cooler temperatures of the outside world.
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hardiness
The ability of a plant to survive is called its hardiness.
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humus
A stable end product of organic-matter decomposition that's believed to increase microbial activity in soil, improve soil structure, and enhance the root development of plants.
Gardening Glossary
Bacillus thuringiensis Bt
An effective bacteria that attacks only the larvae of caterpillar family insects. It is safe to other insects, animals, and humans.
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macronutrients
Mineral nutrients that plants need in the largest quantities: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
Gardening Glossary
mulch
Organic or inorganic material placed over the surface of soil, usually directly over the root zone of growing plants. Used to conserve moisture, kill weed seedlings, modify soil temperature, provide attractive covering to garden beds.
Gardening Glossary
organic matter
Once-living stuff like compost, sawdust, animal manure, ground bark, grass clippings, and leaf mold (composted tree leaves). Used to enrich soil and improve soil texture.
Gardening Glossary
perennials
Any plant with a life cycle of three or more years. Herbaceous (non-woody) perennials include flowering plants and herbs, mainly. Woody perennials include trees and shrubs. Longevity depends on the plant and growing conditions.
Gardening Glossary
pH
The measure of soil's acidity. Soil with low pH means it's too acidic; soil with high pH means it's alkaline. Most plants grow best in soil with a pH value between 6.5 and 7.2. Neutral soils measure 7.
Gardening Glossary
photosynthesis
The process through which plants take nutrients from the air and from the water in the soil to produce sugars that fuels the plant's growth.
Gardening Glossary
primary nutrients
Nitrogen, phosphorous, and potassium are the three nutrients plants need in the largest quantities.
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root crops
Plants with edible underground roots such as onions, carrots, beets, potatoes, turnips. Most root crops are cold-weather crops.
Gardening Glossary
self-blanching
A type of cauliflower with leaves that naturally curl over the head and exclude light. Requires cool temperatures for leaves to curl effectively.
Gardening Glossary
sets
Small onion bulbs, about 1/2-inch wide, that were started from seed the previous year. Grow onion sets with the pointy end up.
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side-dressing
The act of adding a small amount of fertilizer around or "on the side" of plants after they're growing.
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succession planting
Planting small, 2-to-4-foot patches of plants every two weeks throughout the growing season so that you can harvest a crop over an extended period of time.
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thinning
The act of cutting the least robust seedlings in your garden to give the healthier plants more room to grow.
Gardening Glossary
vining crops
Crops that grow on vines, such as cucumbers, melons, pumpkins, and winter squash. They usually require support (staking, trellising, etc.) to keep them off the ground.
