Paul Rabaut raises a type of fly maggot that helps break down heaps of food scraps and other organic waste in the compost bin he maintains at his Riverview home. Rabaut, a biology professor at the Ybor City campus of
Hillsborough Community College, calls himself a “lazy farmer,” but he certainly stays active when he isn’t teaching Introduction to Environmental Sciences courses.
He takes home scraps of food from the HCC cafeteria, throws in food waste from his own kitchen, and tosses into his composting bin whatever else tens of thousands of black solider fly (Hermetia illucens) maggots will chow down on. The larvae will spend around two to three weeks quickly devouring damp waste, especially low-cellulose content. They need to consume as much as they can at this stage, because once they become full-fledged adult black solider flies, they won’t have mouths and therefore will be unable to eat.
“They’re like little batteries,” Rabaut explains, holding a handful of the chocolate-colored maggots in his open palm. “They’re storing up their nourishment, which they will need once they become adults and fly off.”
Black soldier flies don’t have very long to lay more eggs that start the life cycle over. The adults, which look like organ pipe mud dauber wasps and measure about 5/8 of an inch long, have a life span of just five to eight days.
Rabaut says he doesn’t know of anybody else in his circle of gardeners who raises black solider fly maggots, but he says the little buggers are vital to the composting process.
“They’ve turned hundreds of pounds of food scraps into a fraction of the weight,” he says. What’s left behind is black, nutrient-rich compost that he uses in his vegetable garden as fertilizer.
Quipping that he’s “trying to rebrand maggots,” Rabaut devotes much of his effort to ensuring the soon-to-be black soldier flies are happy so they continue producing high-quality, organic fertilizer. And his environmentally friendly approach to gardening doesn’t stop there.
Rabaut, who helped spearhead a sustainability effort at HCC with a recycling initiative called
HCCThinksGreen, collects rainwater in a 1,000-gallon barrel. A few feet away from the hulking rain barrel are aquaponics tanks, which allow Rabaut to raise tilapia and help irrigate his garden with nutrient-rich water. Ammonia from tilapia waste is broken down with beneficial bacteria, and that process produces nutrients for his vegetable plants, which include tomatoes, chard, peppers, corn, and more.
While Rabaut’s “water efficient” gardening and composting systems are complex, he didn’t necessarily spend a lot of green on creating his garden. He figures he spent less than $200 on building the unique composting bin, which is the home of his thriving maggot community. Many of his aquaponics tanks are reclaimed food-grade shipping containers once used to transport liquids such as soda. He found them on Craigslist for around $150 each. He grows many of his plants in plastic 55-gallon drums that he paid $20 for and cut in half to make two planters.
Though Rabaut certainly knows his stuff when it comes to science, he says he learned about sustainable gardening online.
“Almost everything you see in my yard, I learned by watching YouTube,” he says. While he must produce a large amount of compost to fertilize his sprawling garden, he said those who have much smaller gardens can produce ample compost with far fewer resources. “Many people can make enough compost for their gardens by simply filling a 5-gallon bucket with organic waste.”
More composting tips
Conrad Wheeler, a systems program analyst and member of the
Tampa Gardening Swap, is practicing the relatively new field of
vermicomposting – something he learned about a year ago at a class offered by the
Hillsborough County Extension Service; vermicomposting employs earthworms, which convert organic waste into fertilizer. Wheeler estimates he produces 10 gallons of finished material on a yearly basis, a small amount by necessity as he lives in a deed-restricted community and doesn’t have much space for composting.
Limited space and neighborhood rules are the only things that pose challenges for Wheeler’s composting efforts, though. He reports relatively few, if any, problems with the composting process itself. “[I] eliminate the compost pile quickly and just use it as mulch. Florida weather breaks it down quickly.”
While he also uses lawn and shrub trimmings from his yard as mulch, one of the convenient distinctions of vermicomposting is that it can be done indoors, utilizing a bin that sits on a protective tray.
He believes one of the keys to successfully producing compost is knowledge of how composting works. Among the essential things to know?
“A basic understanding of the compost cycle as it pertains to mykos (mycorrhizae) fungi and bacteria to create a healthy soil,” Wheeler says. He also remarks on the importance of not over-fertilizing and adding what he believes are “unnecessary soil amendments,” such as blood and bone meal, Azomite and lime.
Try composting underground
Dyanna Louyakis, a microbiologist at the
University of Florida, takes a different approach to composting than Wheeler – she produces her garden compost outdoors, like most other gardeners do. Louyakis has been “composting solidly” for six years and also grew up composting. She says her compost pile yields roughly 100 pounds of material annually, which she moves to her garden beds about three times per year.
Unlike Rabaut, who uses a raised bin for composting with maggots, Louyakis’ compost pile is buried 12 to 18 inches underground. She says burying her compost helps deter pests, though the method isn’t perfect. “Occasionally, I’ll find raccoon excrement in the pile, but they don’t cause any trouble. The waste breaks down very quickly between the daily rain in the summer and the heat.”
Louyakis fills her compost pile with food scraps, which are collected in a
Full Circle scrap bin inside her kitchen and deposited two to three times per week into the compost heap. Saying that composting is simple, she encourages other gardeners to start a compost pile of their own. “All I do is throw my yard and kitchen waste in the dirt and wait. The only thing I might say is that it’s probably easier than many people think, so just give it a try.”
Valerie Nichols, who, like Louyakis, is a member of a popular Facebook group called
Florida Gardening Friends, says she has been composting for more than 20 years. She produces around two cubic yards of compost each year and has plenty of tips to offer fellow gardeners who want to set up composting systems of their own.
“Pests aren’t really a problem as long as no meat or dairy is added. Too much rain can be an issue if the compost isn’t covered during the rainy season,” Nichols advises. “Grass clippings and leaves can mat if those layers are too thick.”
She says she’s experimented with various composting methods over the years, including using different compost barrels and prefabricated bins.
“They have a limited life, are expensive, and tend to be labor intensive but do produce a lot more compost faster,” Nichols says. She now uses three 4-foot by 4-foot bins constructed of wood and wire. She fills up each as the necessary composting ingredients become available. Each bin takes about a year to produce compost, but the process can be expedited by turning the compost.
Nichols, a retired member of the U.S. Air Force, tells gardeners to keep composting simple. “Don’t worry about getting fancy. Composting can be as easy as simply piling material in the corner of the garden.”