Soil Testing for Rhododendrons
Rhododendrons and azaleas thrive in soils that are more acid based and contain a good amount of compost to aerate the soil. Sandy soil tends to drain water too quickly and soil that has too high a composition of clay will retain water for too long a period of time. Stagnant water will kill your plant.
Long Island soils support a wide range of rhodi's and azaleas. The soils on the North Shore of Long Island tend to be more acidic than those of the South Shore because of glacial activity. Soil with a pH of 5-6 is your goal for soil acidity.
In order to test your soil for the level of acidity you can take samples from a few areas of your garden at about a depth of 6 inches. Mix them together in a small plastic bag and take it to your nearest Cornell Cooperative Extension. There are two offices on Long Island . The Suffolk County Extension office is in Riverhead and the one in Nassau County is in Plainview , across from the Old Bethpage Restoration Village .
These extension offices also sell a kit which you can purchase to do your own soil testing. Their kit seems to be more accurate than those offered by most commercial enterprises.