How do I lower the soil pH for azaleas and rhododendrons?


How do I lower the soil pH for azaleas and rhododendrons?


Home gardeners can lower their soil pH by adding sphagnum peat moss to the soil.  (The pH of sphagnum peat moss generally ranges from 3.0 to 4.5.)  When planting azaleas and rhododendrons, dig a wide, shallow hole.  Backfill with a mixture that is half soil and half moistened sphagnum peat moss.  

After planting, mulch azaleas and rhododendrons with wood chips, pine needles, or shredded oak leaves.  These materials are mildly acidic and help maintain the desired soil pH.  Additionally, sprinkle a small amount of sulfur around plants on an annual basis. 


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on . The information contained within may not be the most current and accurate depending on when it is accessed.