I have found during the past three years, that by adding gypsum at the rate suggested by Bob Beyfuss in Scott Persons book. 5 lbs per 100 sq ft. If applied twice(fall and spring), my soil tests show an average calcium increase of 1800 ppa more than the amount before applying. This is what I have found with my type of soil. Gypsum plus bone meal may raise the calcium quicker. Then on established beds, test every two - three years
and apply more gypsum if needed.
Here's what Bob Beyfuss says about applying gypsum. Also says not to apply any Phosphorus or nitrogen fertlizers.
\"If soil calcium levels are below 2,000 pounds per acre apply 50 pounds of gypsum per 1,000 square feet. If soil calcium levels are below 1,000 pounds per acre, look for another growing site. Never add manure, compost, phosphorus or any type of nitrogen fertilizer to a ginseng planting. A one to two inch layer of well-rotted or shredded hardwood leaves (preferably sugar maple) from the forest floor may be tilled in the soil.\"
Here's the complete article:
I feel that Calcium is the most important thing we can add to our ginseng beds. It causes healthy growth and helps protect from diseases.