What Kind of Soil Do Azaleas and Rhododendron Need?
What Kind of Soil Do Azaleas and Rhododendron Need? Azaleas and Rhododendron are plants that love acid soils. They need the nutrients that low pH acidic soils provide. Their health depends on soils that range from 6 – 7 on the pH scale. If the pH moves up above 7 (alkaline range), the soil nutrients get tied up and can’t be used. Camellias and Blueberries also need a low pH (acidic).
Lowering the pH
Some essential nutrients including Iron become more available to plants as pH levels drop. a pH of 5.5 allows acid loving plants to access the nutrients they need to thrive. Do a soil test to determine the pH of your soil. If the pH is too high (7+), use sulfur to lower it. We like Espoma Organic Soil Acidifier, using 1.5 cups for new plants and 2.5 cups for established plants. Apply at the drip line in the Spring. Wait 60 days, check the pH again and reapply if necessary.
Signs of Nutrient Deficiencies
There are a couple of signs that your acid-loving plants are struggling in alkaline soils. Leaves that turn pale green or yellow between the small leaf veins. This is an Iron deficiency called Iron Chlorosis. If the outer edges of the leaves are yellow, it is often a Magnesium deficiency. Nitrogen deficiencies will present an overall yellowed leaf. Espoma brand Organic Holly-Tone can help correct these problems. It contains Sulfur & Magnesium as well as Nitrogen, Phosphate & Potash. Apply 1 Cup per foot of branch diameter & double the rate if your shrub is larger than 3 feet.
The point is, if your soil’s pH is too high (7 or above), the soil chemistry will no enable the plant to take up the proper nutrients. It doesn’t matter how much fertilizer you have thrown on it. Espoma products help you correct these things. As always, adding sufficient amounts of organic matter into the soil when planting helps get that plant off to a good start too! Check all your Azaleas and Rhododendron this Spring to keep them healthy and thriving.