VEGETABLE VARIETIES for GARDENS (VVfG) UPDATE - Soil Testing

At its recent February meeting the Rensselaer County Master Gardeners decided to test the soils in their vegetable planting beds. The beds have been used for a number of years with minimum fertilizer, but often mulched with shredded bark.  The gardeners will take samples from each of the 9 beds,  combine them into a single sample and send that sample for a complete analysis in March. If there are nutrients that need to be added or the soil pH level  needs adjustment, there  will be time to start those amendments in advance of the growing season because  soil adjustments can  require weeks to take effect.

Healthy soils, healthy plants

When is it necessary to have garden soil tested? 

If you are planning to grow more than just a  couple of tomatoes and a little lettuce, or if you only have a 4' x 4' raised bed and noticed lots of earthworms when you filled the bed, maybe you're okay.  On the other hand, here are a few reasons to test:  

1. Do you have a new garden location? - In new housing developments, sometimes builders remove/replace top soil. In older homes, the backyard frequently was the spot where the excavated  subsoil from the foundation  was dumped, or it was where the coal ashes from an old furnace were used to fill a low spot.
2. Have you been using the same garden plot for years and only adding  a sprinkle of 5-10-5 fertilizer from  a bag,  and your yields seem to be declining? You might have some micronutrient  deficiencies.
3. Do the leaves on your plants seem smaller than normal, look pale or a little yellow? Do the underside of your tomato leaves have a purplish tint; or are the leaf edges brown and curled? The soil may be  in need of nitrogen, phosphorus or potassium.  

   

   Blossom End Rot Source: T.A. Zitter,
   Cornell University, Ithaca, NY

4. If the soil is deficient in calcium,  your tomatoes will develop blossom end rot.
5. Do your plants look green and bushy, but set little fruit?  Maybe you have excess nitrogen in the soil.
6. For a longer list of symptoms, check  this  chart from the Arizona Extension Service, but realize that... 

Diagnosing nutrient deficiencies (or excesses) can be tricky, because many plant symptoms overlap; and there can be multiple  conditions needing attention.   The Rensselaer County Extension Service and the other area Extension Services offer both simple pH testing as well as more extensive soil analysis.  These services typically only cost a few dollars, and the results will be returned to you promptly along with advice on how to fix any problems.  But, it is really important to get the testing done early in the spring in order to start soil remedies.

VVTG is a public science effort coordinated by  Cornell Cooperative Extension  to collect and share the practical experiences of  Master Gardeners  maintaining demonstration vegetable gardens.