The dirt on compost: Tips and tricks from UW Garden Expo

Readers may have missed that we are coming to the end of International Compost Awareness Week, May 4 – 10. 

At Big Horn County UW Extension’s recent Garden Expo, held April 30 in Basin, UW Extension Horticultural Specialist Richard Woodward shared the importance of composting and how to start a system at home. 

“Approximately 60% of the solid waste nationally could be classified as organic,” Woodward said, “It’s either paper, food scraps, yard trimmings, wood – 60% of what we throw away. So we have to find an ecologically better way of disposing of that, and one way is composting.”

Compost can help soil hold moisture in dry conditions, suppress plant disease and improve soil quality. 

“Basically, healthy soil equates to healthy food,” Woodward said.

Common household waste is just waiting to be utilized. 

Starting your own pile

Things to consider when starting a compost pile include available space, time requirements, cost and how your neighbors will feel about the proximity. 

The minimum recommended pile size is one cubic yard. While inoculates are sold to start the bacteria culture in your pile, Woodward recommended sticking with what you’ve already got. 

“Pretty much everything you need to compost is in the pile itself,” he said. If you have a little finished compost on hand, adding that to a new pile can help kickstart the process. 

When placing new material in a compost pile, breaking it up into small pieces will speed up decomposition. A three-pile system tends to speed up composting even more.

Three piles allow space for different
levels of decomposition to take place. Fresh organic material can be placed in one bin, then moved down the line as it becomes more broken down.

“It speeds up the process, I’d say by half,” Woodward said. 

Piles can be contained in a wire fenced area, a wooden crate, bins, or just flat out on the ground. Direct incorporation is the process of simply dumping organic waste in a hole and covering it up. 

More advanced systems include a turning barrel, which can speed up decomposition by allowing easy aeration. Vermicomposting, where worms are added to the mix, can add nutrient-rich castings to the compost and speed up decomposition. Woodward recommended red wigglers. 

When Wyoming winter freezes the compost pile, Woodward suggested to continue adding scraps. It will thaw eventually. 

Why compost stinks

In order for the decomposition process to be the least smelly and most effective, Woodward suggested a mixture of four “browns” to one “green.”

Brown additives are high in carbon; they include dead materials such as leaves and paper products. Greens are higher in nitrogen and include grass clippings, vegetable scraps and manure. 

High carbon will lead to dry, slow decomposition, while a low quantity will result in a wet, dense compost pile. When nitrogen is low, decomposition is very slow. When it’s too high, excess ammonia can be produced and create an unpleasant odor. 

Too many grass clippings are a common culprit of a stinky pile. Woodward recommends leaving some clippings to dry on your lawn first in spots that appear to be struggling, which can add nutrients back to the soil and make the clippings more compatible with a compost pile. 

Avoid adding cat and dog feces, which may spread disease, to your compost. If adding weeds to the mix, clip off their seeds to avoid starting a pest garden. While dairy and meat products can be added, Woodward suggests leaving those out to avoid the odor and critters they draw. 

Water is a big part of the process. An ideal compost pile has a moisture similar to that of a wrung-out sponge. 

Aeration is also important to a compost pile, so that the bacteria and microorganisms can breathe. Low oxygen can cause compost to stink. 

Turning the pile allows microbes to heat the waste as well, with temperatures reaching 90-150 degrees Fahrenheit. At 150 degrees, weed seeds and disease will be killed off. 

Compost in practice

Ideally, compost will suppress plant disease, improve soil quality and increase soil moisture. However, if too much is added, compost can burn plant roots. The addition of 10-15% compost to a soil mixture is the sweet spot, Woodward has found. 

When tilling soil, adding one to two inches of compost to ten inches of topsoil is a good start. 

“It will help heavy clay soils immensely. If you have problems holding water in your soil, this is your ticket,” Woodward said. 

Quality varies from pile to pile depending on what was added to it, which does not make compost a good substitute for fertilizer. When adding organic matter to your pile, consider chemical additives that may remain in your compost. 

“Compost is a huge thing… It’s a very worthwhile thing,” Woodward said. 

For more gardening and agriculture information, visit https://wyoextension.org/bighorncounty/ or stop by the local UW Extension office at 208 South 5th Street in Basin.