A composted mixture of 95% sawdust and 5% biosolids, Groco’s biosolids are a by-product of King County’s wastewater treatment plant in Seattle. The high composting temperature in effect, pasteurizes the Groco, leaving it virtually odorless and free from imported weeds. Groco is a superb organic soil conditioner for landscaping, but is not recommended for vegetable gardens. To apply, first loosen the existing soil, next spread Groco 1” to 3” deep on the area to be planted, finally till or spade the Groco into the soil. Groco is also an excellent alternative to beauty bark as mulch that will help retain moisture and add beauty to the landscape. It will leach nutrients into the soil below to help your plants grow. To apply as mulch, spread it 1” to 2” deep. As with any mulch, application around the base of shrubs should be thinner.