Soil testing critical to plant health

Q. Can you help me understand my soil test results? I’m having a terrible time with blight on my tomatoes and need to know what to do.

Judy from Salem

A. Anytime you get your soil tested, be sure the company gives you a summary report along with recommendations. Many locations give you levels but forget you need help correcting your soil.

Soil testing is an excellent measure of soil fertility and an inexpensive way of maintaining good plant health. A standard soil test provides the status of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), pH, cation-exchange capacity, lime requirement index and base saturation.

This may sound like too much information, but don’t worry. We can help you interpret the results and recommendations. With a representative soil sample and an accurate test, sound fertilizer recommendations can help you improve plant quality and productivity, and save money, too.

Judy’s soil test results will help her be sure her soil has the proper pH and nutrient levels to grow great tomatoes. But what the test will not provide is any measure of soil disease or how to prevent it. Disease lives in the soil and affects our tomatoes to some degree every year. Most of us fight early blight on tomatoes every year. This year was a stellar year for early blight.

In general, the answer to early blight is not just “spraying” to keep the disease at bay. In fact, spraying correctly is quite a challenge and must be attended to on a regular basis. Thus, we recommend it as a last resort. There are many other options to try first.

Gardeners need to understand that early blight is soil-borne. So if we can keep soil from splashing on the plant leaves, we can reduce infection. Mulching (usually with flat newspapers, then some kind of mulch on top), will go a long way in reducing splashing. Proper staking, distance between plants and sometimes pruning of lower leaves will help reduce leaf wetness and the chance of infection. To learn more about and develop your plan for next year’s tomatoes, go to: http://go.osu.edu/earlyblight.

Eric Barrett is OSU Extension educator for agriculture and natural resources in Mahoning County. Call the office hot line at 330-533-5538 from 9 a.m. to noon Mondays and Thursdays to submit your questions.