Fall leaves turn to ‘black gold’ in summer

Andrew Shurtleff

Supervisor of North Grounds Tim Spencer (left) and equipment operator Frank Hill take dirt from U.Va.’s compost pile on Observatory Hill. The 10-year-old heap is currently 30 feet wide by 30 feet deep and about half as long as a football field. U.Va. landscapers use the compost as a soil enhancer and top dressing in every garden on Grounds.

By Matt Kelly

Leaves, an integral part of autumn, are an issue for the University, which deals with millions of them every year, starting in November and ending in the middle of January.

Leaf collection cost U.Va. $197,787 in fiscal year 2003-2004, almost all of that in labor costs. Once collected, the leaves are then composted for use by University landscapers.

The compost is “black gold, a gardener’s best friend,” said landscaper Melissa Y. Shirley-Miller, who works the gardens on the east side of the Lawn.

“It’s used in every garden we have,” she said. “In a hot summer, no plants die. Amend the soil with compost, and it adds 20 years to the life of the plants.”

These benefits of compost aside, the leaves need to be picked up before they kill the grass.

“We over-seed the lawns in the fall,” said Richard M. Hopkins, superintendent of landscaping. “If we leave the leaves there more than four or five days, when we take them up, the lawn is yellow.”

The leaves are collected by hand, with employees raking or blowing them into piles. Then they are vacuumed into trucks. The vacuums break the leaves down, reducing them to one-fourth their original size.
The vacuums exert such suction that employees have lost hats and other articles of clothing to the machines, Hopkins said. One employee lost a coat he had tied around his waist.

Employees try to separate debris from the leaves before they vacuum, but miss things. Cans and keys have been vacuumed up into the trucks, and about 20 years ago, a pistol was sucked up and destroyed by the impellers that drive the vacuum, Hopkins said.

Once vacuumed and chopped, leaves from thousands of trees are added to a compost heap that is currently 30 feet wide by 30 feet deep by 150 feet long — about half as long as a football field — on the back of Observatory Hill, where it has been accumulating for about 10 years.

Brush, which had once gone on a separate pile, is now ground up and added to the compost heap as well. There was discussion about composting kitchen scraps, but that idea was ultimately
rejected because it would have incurred additional regulation.

U.Va. is allowed to maintain its compost operation only for material collected on site, and the compost must stay at U.Va. because it is state property. “The only way we can dispose of it is through state surplus sales,” Hopkins said.

This means U.Va. landscapers get to use as much compost as they want, as a soil amendment for gardens and as top-dressing for lawns and playing fields.

Since the University produces more compost than it uses, the heap grows every year, which poses a challenge.

“The pile is so big, we can’t turn it enough to get up the temperature,” Hopkins said.

Turning a compost pile introduces air into it, allowing the temperature of the material, through the rotting process, to heat up. Properly maintained piles will reach a temperature of 160 degrees, which kills weed seeds. Hopkins noted that the compost his department uses contains some active seeds, so that weeds grow where the compost is spread.

The O-Hill compost pile also produces its own crops. Last year, pumpkins grew from the heap; the year before, watermelons.

“You can have a nice garden there,” Hopkins said. “[The compost] will grow whatever gets sucked up into it.”