Choosing topsoil

There are numerous ideas and misconceptions about what constitutes good topsoil. Some gardeners have the idea any and all material sold and marketed as topsoil has some magical ability to grow plants. Once unloaded off the truck and graded out, the true characteristics begin to appear...clods, rocks, cans, plastic bottles and roots. You also can receive numerous exotic weed seed.

Landscapers and home gardeners should be very particular about using topsoil on their planting projects. Thought should be given to the texture, structure, organic content and to some degree, color. The biggest problem with using bulk topsoil is low pH and nutrient content. Both of these can be corrected with lime and fertilizer. The one thing to remember is that the native makeup of the soil remains unchanged.

Listed below are some general guidelines for evaluating topsoil. A soil test by NCDA is always recommended and the ranges should be as follows:

pH 5.8-6.2

P-I (phosphorous index) 50

K-I (potassium index) 50

Ca (percent calcium) 45-60

Mg (percent magnesium) 10-15

BS Base Saturation (percent) 75-80

Mn-I (manganese) 25

Zn-I (zinc) 25

Cu-I (copper) 25

CEC exchange capacity is the measure of the quantity of nutrients the soil will hold. Sand is lower then clay. Clay is typically in the 8-10 range.