Herbdoc dishes some “dirt.”

When I first started gardening, the only thing I was concerned about was the pH of the soil.  As everyone who lives in Rhode Island knows, our soil tends to be on the acid side.  I would unscientifically broadcast lime every couple of years and hope that I was improving the pH of my wooded property.  It was only after I took a landscaping course last year and decided to plant wildflowers in a secret garden in the previously unplanted woods that I found out just how acidic the original soil was.

I had the soil in my established herb, perennial and vegetable beds analyzed by UMASS (the University of Massachusetts) about three years ago, and I highly recommend this lab.  They not only provided the pH of the samples but also gave the amounts of nutrients (phosphorus, potassium, calcium and magnesium) and micronutrients (sodium, sulphur, manganese, copper and zinc) present in the soil.  The latter determine the amount of fertilizer needed for optimum growth.  Organic recommendations are also given.  Since I had regularly added compost and rotted manures along with the unscientific amount of lime to my established gardens, all of the results came in at optimal levels.

When I decided to have the proposed secret garden’s soil tested, I was amazed to see the pH at 4.5.  Micronutrient levels were all in the normal range as were potassium and magnesium, but calcium and phosphorus were low.  The organic matter was said to be quite high which will provide a good growing medium for the intended perennial wildflowers.  UMASS recommended adding about 1 part compost and 2 cups of bone meal to every ten parts of soil and broadcasting a light top dressing of lime to the area. They also suggested retesting next year.

In the long run, the cost of the test ($9) is well worth the price.  When gardeners guess about what their plots need, money is wasted by buying too much or losing plants to inappropriate environments.  If too much fertilizer is used, run-off to ground water occurs and natural resources are compromised.  Too much lime can cause soil pH to rise above the needed level which makes micronutrients less available to plants.  When too little fertilizer or lime is applied, the plants can’t access what they need to grow.

Visit www.umass.edu/plsoils/soiltest for further information on soil testing.  The form will tell you everything you need to know about the proper procedure for taking and mailing samples to the lab.  Results can be sent to you by e-mail or by snail mail.