I live in USDA zone 7a/6b depending on which map you consult. I planted 2 azaleas 2 springs ago. The plants are approximately 16 feet apart, in an area with low sun to dappled sunlight. We mulch yearly with good quality mulch, as well as fertilize, compost and maintain soil acidity. The soil is well drained and the plants have adequate water. The trouble is the bushes have stunted growth and don't bloom. They have dark green healthy leaves and appear to have no discernible problems. What can I do?
This may be a case of excess Nitrogen in the soil. Over fertilizing will lead to green, leafy plants and no flowering.
You can do a soil test to determine if this is the case.
Your County Extension Office will help you with a soil test for a few dollars.
Here is a link to help you locate your nearest office.
Here are some articles to help with Azalea care.