Don Baltes said he tops off his garden each year with the help of Olmsted County.
Recently, he visited the county’s compost site at 305 Silver Creek Road NE to pick up a few buckets of fresh compost.
“I like to do that yearly, just to freshen it up,” he said, noting the added benefits are getting a bit of exercise and knowing it’s good for the environment.
Nearby, Richard Sim and his son, Kyle, were shoveling compost into the back of a pickup, planning to add the soil to their garden.
While not in the same yearly routine as Baltes, Richard Sim said he’s discovered the benefits of using compost, which is generated from grass clippings and leaves dropped off at the county site.
Tony Hill, the county’s director of environmental resources, said the compost appears to remain a secret to many, with more residents dropping off grass and leaves than are picking up the resulting compost.
“We’re just kind of being overwhelmed with the amount of materials we’re getting in,” he said.
Nearly 12,000 cubic yards of “feedstock” — the grass and leaves — are received each year and only 3,600 cubic yards of compost are distributed.
On average a third of the feedstock volume is lost in the composting process, but that still offers an estimated imbalance, with more than 4,000 cubic yards of unclaimed compost produced each year.
The imbalance has required the county to expand its compost site. Last year, it added 11.2 acres to the area used to convert the feedstock into usable compost.
Master gardener Kay Eberman said the lack of use surprises her.
“I’ve used it almost every year,” she said, noting the compost has done everything from filling a former well site on her property to serving as top dressing for her gardens.
Eberman said she conducted an informal survey about what might keep people from using the site and discovered a big deterrent is worry that the original lawn clippings might contain pesticides or herbicides, which would end up in the compost.
Anthony Wittmer, the county’s environmental resources communications specialist, said such concerns are misplaced. Each year, he said the site is tested for 30 types of pesticides to ensure residual chemicals aren’t found in the compost.
“We aren’t required to test it, but proactively do so for our customers’ benefit,” he said.
Additionally, the composting process, which takes 60 to 90 days during warmer months, burns off weed seeds that might have been delivered with grass clippings.
Still, Wittmer said it’s important to note the site is open and cannot control for seeds that wind or wildlife might deliver.
With that slight risk, Eberman said she recommends using the compost for a variety of garden benefits.
“It should be an ideal soil for a full garden or for top dressing, because it’s nutrient-rich and weed free,” she said, noting the compost is looser than area soils, making it a better choice for root growth.
While the county is seeking to encourage greater use of the compost, Wittmer said it’s also encouraging homeowners to consider an option for reducing the amount of compost produced each year.
He said the environmentally friendly option is to mulch grass clippings, rather than bag them and drive them to the compost site.
“It is preferable to let nature take its choice directly where they lay,” he said.
Eberman said that when it’s done right, mulching also improves lawns.
“They do better if you mow them high, and you use a mulching mower so the clippings are added back to the soil, because they do break down and add nutrients,” she said.
The University of Minnesota Extension suggests “as a general rule, grass clippings of an inch or less in length can be left on your lawn where they will filter down to the soil surface and decompose quickly.”
If composting on site, Wittmer said the only added precaution is the need to ensure clippings don’t end up on sidewalks or other surfaces were they could easily wash into storm drains.
“Eventually, that can have potential water-quality implications,” he said.
Still, he suggested the added effort provides a win-win for the homeowner and county by creating better yards and reducing the growing burden at the compost site.