Testing for chromium is a precaution every gardener should take if their property contains old lumber or was the site of an old mill. Copper, chromium and arsenic were used to treat lumber for a long period of time. Even though they are no longer in use. traces can leach out of the wood and into your soil. Chromium can be toxic, killing plants and making the soil infertile.
Dig a hole that is 6 to 8 inches deep. Remove the soil. Make a slice in the side of the hole with the garden shovel. The soil sample should be 1 inch wide and run from the ground level to the bottom of the hole.
Put the soil in a plastic bucket. Do not use metal because it can add contaminants to the sample.
Collect random samples from all over the planting area. Zigzag through the yard, collecting soil once every 100 feet. This will give you a clear representation of the soil you have in the area.
Break up dirt clumps and mix the soil together well. Pour the soil out of the bucket and spread it out on newspaper. This will dry it.
Put about a pint of the soil in a plastic bag to send to a testing lab. Make sure the bag is sealed tightly.
Send the soil sample to your local university agricultural laboratory, county extension office or commercial soil testing facility. Ask for a soil analysis including nitrogen, phosphorous and potassium levels, soil texture and pH levels. Also request a test of the chromium levels.
Analyze the results of the test to determine which plants you can put in the ground. With the help of a landscaper or expert with the county extension office, determine if you need to treat or amend the soil before planting.