Mulch mowing: Leave the blower behind
Tuesday, November 16, 2010
WINTERTHUR, DEL. - I am trying to be smug when I tell the garden honchos at Winterthur, the du Pont estate north of Wilmington, Del., that instead of blowing and bagging leaves, I just pick them up with the lawn mower. The bag fills, I push the mower up the hill to the far corner of the yard and just pile the stuff on the compost heap.
The leaves turn to black gold, my carbon footprint is reduced and the landfills are spared.
Carol Long and Chris Strand shoot me the sort of look that says: Are you crazy?
For more than 20 years, the gardeners at this expansive and famously leafy estate have been mowing leaves with mulching lawn mowers. The machines inhale the leaves, chop them into shreds and deposit them as the mower moves along. Engine noise is confined to the muted chug of the mower, not the incessant high-pitch whine of the leaf blower.
And there are no bags to unhook and drag anywhere, just a confetti-like litter left on the grass. Ripped into morsel-size pieces, the flakes melt away in two or three weeks as microbes and worms do their work of enriching the soil. The inherently thicker litter in the woodland beds is more slowly consumed but is gone by spring.
It is such a simple system that Strand, garden director, and Long, assistant garden curator, wonder why it hasn't caught on. They are certainly converts in their own gardens. "I spend a fraction of the time I used to spend raking and transporting leaves," says Strand.
Mulch mowing won't interest the person who craves noise or needs to blow every wayward leaf from his manicured lawns, but for the rest of us, it seems like a pretty good way to deal with the effects of nature and gravity in November.
When H.F. du Pont lived here, he had an army of 90 gardeners hand-raking the leaves, which must have been both Zen-like and manic. The woodlands generate about 500 tons of leaves a year, says Strand. Now, as a public museum and garden, Winterthur relies on a gardening team of 16 and has come to count on this highly efficient approach to the leaf drop.
Kevin Stouts, one of Winterthur's mower meisters, uses a riding mower (a commercial model with a 48-inch mowing deck) and a simple 20-inch push mower. Mulch mowers are designed for chopping up grass blades finely, so that they will break down quickly in the lawn. They have blades that are angled at the edges to create a vortex within the mowing chamber that suspends the clippings for a good chop.
Some mulching mowers have double blades for extra-fine chopping, but even non-mulching mowers will do the job, Stouts says. The important thing is to remove any bag and close the discharge chute. My mower at home came with a hard plastic plug to seal the bag chute for mulching, which is fairly typical.
Making the cut
The system works thus: With lawns, frequent mowing is best to avoid leaf loads that may slow the mower's progress. Just as you should mow the lawn every three or four days in the frenetic growth of a wet spring, a twice-weekly leaf mow in the fall will stop things from getting out of hand.
The mower seems most efficient when reversing, says Stouts. "There's a lot of back and forth activity to get that real clean look," he says.