One of the fun parts of my job is helping residents solve problems in their lawns and landscapes.  Many times, folks will call or stop by the office to pick up a soil test bag and form, and I cannot help but be curious about what they are growing or what kind of lawn and garden project they might be starting.

Sometimes, I get to visit with folks who have plants that are dying or already dead, and they want to submit a soil sample to find out what’s wrong with their plants.  A soil test is good, but it might not be the best tool for diagnosing dying plants.

The Soil and Water Lab at Texas A&M in College Station tests soil for homeowners and farmers all over the state.  Soil tests help us to know a lot of information about our soil such as the pH, the nutrients available to plants, the soil texture, the amount of organic matter in the soil, and salinity.  The information we get from a soil test helps us to know more about the conditions of the soil and what our plants might need to grow well.  A soil test report will have fertilizer recommendations based on the type of plants you are trying to grow like lawn grass, vegetables, fruit trees, or crops.  You can find the soil test forms and instructions on their website at http://soiltesting.tamu.edu/.

If a plant is diseased, the best place to turn is the Plant Disease Diagnostic Lab at Texas A&M University, also called the Plant Clinic.  The team at the lab has created a great guidebook online that describes a lot of plant diseases and symptoms.  If I cannot diagnose the problem by visually inspecting the plant, the next step is to submit a sample to the Plant Clinic.

The Plant Clinic runs tests on plant samples to find out what is killing plants.  They can test for a wide range of plant diseases from oak wilt to large patch in turfgrass to rose rosette virus.  The lab runs a variety of tests, depending on the plant and the potential problem.

When the lab technicians receive a plant sample in the lab, they will inspect the plant to determine what kind of tests they need to run.   The lab tests can take anywhere from 11 to 21 days because the lab technicians use your plant sample to grow out the pathogen for identification.  Think back to your high school biology lab days with petri dishes and microscopes, and the Plant Lab has even more fun equipment.  It can take a few weeks to get results back from the Plant Clinic, especially during peak season of spring through fall.

The fee for a routine diagnostic test is $35 per sample, but keep in mind that a more complex diagnostic test might cost more and take longer if the lab has to run more tests.  If you need to send in a sample, the Plant Clinic website has some great videos and instructions for collecting, packaging, and mailing a sample so it arrives in good shape to the lab.  The lab needs to have living plant tissue with some disease symptoms, but they cannot do anything with a dead plant.  Check out their website at https://plantclinic.tamu.edu/.

For more information about lawn and garden topics, contact Kate Whitney, Williamson County Horticulturist, at 512-943-3300.