Sparse rhododendrons

Asked May 4, 2016, 6:33 PM EDT

Hi, these rhododendrons have had sparse leaves for a number of years. Can you tell me why they aren't flourishing? I'm including an image. Thank you for your help.

Ramsey County Minnesota flowering shrubs

1 Response

Thank you for the question. Your shrub certainly is flowering well so that's a good sign that all is not lost. Azaleas and rhododendrons require certain conditions to do well. An acid soil that is well drained and moist is very important. Their shallow, fibrous root system can dry out quickly or be injured by cultivation so be sure to mulch well around the base of the plant and water well during weeks where we don't get much rain. Applying an acid fertilizer twice during the growing season is helpful. Light conditions are important too. Azaleas can handle full sun to some light shade but rhododendrons prefer slightly shadier conditions. Read our publications on growing azaleas and rhododendrons: http://www.extension.umn.edu/garden/yard-garden/flowers/azaleas-rhododendrons-for-minnesota/

Thank you for contacting Extension.