Tuesday, January 8, 2013

Free Mulch v. Bought Mulch

Speech to Grants Pass City Council, 1/7/09

Another fall has passed, and the City’s grounds crew has again tried to clean every last leaf out of the shrub borders surrounding City Hall and city parking lots.  This is futile, expensive, and bad for the soil, trees, shrubs, and water quality.
            I thank Laurel Sampson for whatever she may have done to ensure that the Rogue River Highway project used coarse bark, rather than soil-killing fine bark on their water-absorbing settling swales.  Now the city should do its part to reduce runoff and save taxpayer money by using Nature’s free mulch on its properties, provided and spread heavily every fall and lightly throughout the year, with no effort or expense to taxpayers.
            The problem with leaf mulch is that it is spread messily, in places where we don’t need it as well as where we do.  We don’t need to clean every bit of it up, take it away, compost it, and then not even use the compost, but that’s what the city does.  And then the city has tended to cover the bare soil with soil-killing fine bark.
            Leaves are needed to feed the soil that feeds the plants.  Many of the softer leaves are eaten by the life of the soil before winter ends.  This loosens the soil and increases its ability to absorb water, as well as providing food for plants.  When leaves cover the ground two inches deep, they also tend to prevent germination of weed seeds, reducing weeding labor.
            It takes a lot of labor to clean leaves out of shrub borders, and the job is never done; trees are messy, and drop litter throughout the year.  It is easy to blow and rake leaves from sidewalks and lawns into shrub borders, and once the soil is well covered, it looks good—certainly a lot better than a few leaves scattered on bare soil or Red Death.
            One problem with using leaves as mulch is that they can be blown out of place by the wind, and the softer ones are eaten quickly, leaving the soil bare.  One way to deal with this, cheaper than cleaning them all up and spreading bark afterwards, is to cover them with a light coat of walk-on-fir or other coarse bark.  This keeps them in place until they are eaten, and keeps the soil covered afterwards.
            It’s too late for the city to use its raw leaves this year.  But the city can start to bring life back to its soil by spreading compost from Jo Gro, the city’s own commercial composter.  It’s a good idea to cover compost with walk-on-fir, as compost is half-digested and is consumed faster than leaves.  By next fall, the city’s shrub borders could have enough life to consume its leaves.

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