Soil is like an all-you-can-eat buffet for plants. Soil provides food to plants and different kinds of plants need different kinds of nutrients. A soil test can help you decide what fertilizers and organic amendments you can add to your soil when improving lawns, flower beds, or vegetable gardens.
Most often, a soil test is a good place to start when your plants are struggling or before beginning new plantings. Soil can also be tested at any time although spring and fall sampling are usually the most convenient.
Digging into details
Colorado State University performs basic soil tests for $21 per sample that provide gardeners with a variety of soil nutrient information. Soil can be tested to measure soil pH which is the acidity or alkalinity of the soil, organic matter, salts, nitrogen, and micronutrients like phosphorus, potassium, zinc, iron, copper, manganese and lime. For more information, call 1-970-491-5061 or click here.
Each report interprets the various numbers and offers soil management suggestions. Master Gardeners at the Colorado State Extension office can also help you interpret your soil test.
Soil test information allows you to amend your soil with fertilizer and organic matter so that whatever you plant in a given area will thrive. For example, lawns need a different mix of fertilizer nutrients and organic matter than native perennials or vegetable gardens. You will need a soil test for each area of your yard depending on what you want to plant.
Bringing it together
Collect a sample with a garden trowel, shovel or bulb planter. Each sample should be a mix of soil collected from randomly selected spots within the planting area. Do not include any sod or plant matter.
How deep you dig is critical and varies by the type of test and for various labs. Follow sampling depth directions given by the lab. For example:
Garden (vegetable and flower) - 6 inches
Lawns, new (prior to planting) - 6 inches
Lawns, established - 3 inches
Collect the soil in a clean plastic pail and mix thoroughly. Place about one pint of the soil mix into a sample bag or box. Label the sample container (for example front lawn, vegetable garden or flower bed) and keep a record of the area represented by each sample taken before sending the samples to the soil-testing lab.
If the plants in your home landscape are struggling, the problems are not always soil related. A standard soil test will not identify the most common garden problems of watering, sun exposure or lack thereof, poor soil drainage, soil compaction, diseases, insects, weeds, poorly chosen varieties, or neglect.
Contact the Colorado Master Gardener Help Desk at 636-8921 or CSUmg2@elpasoco.com. Hours are 8:30 a.m.-4:30 p.m. Mondays through Thursdays. For gardening information and additional links, visit the Colorado Master Gardener Web site.