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Screening Garden Soils for Lead

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BURLINGTON – Whether new to gardening, or growing vegetables for years, gardeners should understand the importance of getting soil tested for nutrient levels, soil pH and having garden soil screened for lead.

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U.S. Department of Agriculture’s Natural Resources Conservation Service staff use cutting-edge technology to screen garden soils for lead at a Vermont SoilSHOP event.

Although lead, a bluish-gray metal, occurs naturally in soil in small amounts, typically less than  41  parts per million (ppm), higher levels in garden soils may necessitate a range of actions to limit exposure, especially among children who are at increased risks to its health effects.

If living in the Burlington or Rutland area, your  garden soil can be screened for lead for free at one of the upcoming walk-in clinics called SoilSHOPs,  in partnership with the University of Vermont (UVM) Extension Master Gardener program, Agency for Toxic Substances and Disease Registry and the U.S. Department of Agriculture Natural Resources Conservation Service.

The first clinic will be held May 25, from 10 a.m. to 2 p.m., at the UVM Horticulture Research Center, 65 Green Mountain Dr., South Burlington in collaboration with the Friends of the Hort Farm’s Bloom Time Festival.

You may bring a soil sample to the Godnick Adult Center, 1 Deer St., Rutland on June 1, between 9 a.m. and noon. This event will be held in conjunction with the Extension Master Gardener Rutland Chapter’s annual plant sale.

Visit  go.uvm.edu/gardensoilleadscreening  to learn more. You do not need to register in advance. There is a limit of three samples per family.  Trained volunteer health educators will be on site at these walk-in clinics to provide detailed information based on screening results.

Collect one sample from a large garden. With multiple, edible gardens in different locations, sample each separately.

Ornamental flower gardens do not need to be tested  unless they include edible plants.  

Submit a soil sample to the University of Vermont Extension Agricultural and Environmental Testing Lab (go.uvm.edu/soiltest). The lab will run a basic soil test for $17, which provides information on pH, available macronutrients and micronutrients, organic matter and other soil components, along with  fertility  and lime recommendations.

A heavy metals  test (including lead) is available as an add-on or on its own for  $15. Results include possible management options if needed.

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Gardeners interested in having their garden soil tested for lead should follow this illustration to collect their soil sample.

If taking a sample from a large area, collect soil from 5 to 10 random spots throughout the area.  For small beds, choose three spots at random.

Dig down to 6 to 8 inches deep in each location, then combine the soil samples in a clean container. Be sure to remove any pebbles, roots or other debris.

Let the sample air dry. Do not use a hair dryer, oven or flame. Once dry, scoop one to two cups of the mixed soil and transfer to a clean one-quart zipper or slider storage bag.

Wear gloves when collecting a soil sample. If taking more than one sample, rinse the shovel and container between samples.  For  multiple samples, label each bag.

For questions about soils, soil testing and gardening topics, contact the Master Gardener Helpline at  go.uvm.edu/gardeninghelp. Helpline volunteers are available to take phone calls on Thursdays from 9 a.m. to noon through October 31. The number to call is (802) 656-5421.

Debra Heleba is the Extension Community Horticulture Program director at the University of Vermont.

Debra Heleba

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