Get Ready to Start Digging
Time to transplant azaleas and other acid-loving plants
Mid-August to early October is the time to transplant azaleas, rhododendrons, mountain laurel, andromeda, leucothoe and blueberries.
What do blueberries have to do with azaleas and these other landscaping plants?
By August, all have stopped producing top growth and are now making root growth. Transplanting them at this time of year enables the plants to become well established before the ground freezes.
They’re also all acid soil lovers.
Whether you are transplanting or caring for established plants in this acid-loving community, have your soil tested.
Commercial growers of these species adjust the pH of the soil to between 5.0 and 5.5 to keep it acidic. Soils with pH’s below 5.0 have very little calcium, which is as important to the growth of plants as it is to building strong bones. So plants growing in soils with pH’s below 5.0 are very slow in becoming established and do not grow vigorously the following year.
Soil testing helps you identify the pH of your soils and whether you need to supply additional calcium — or other nutrients — for optimum growth.
To supply adequate calcium, growers often apply 300 to 400 pounds of gypsum (calcium sulfate) per acre of land. The calcium in gypsum is immediately available to roots of plants, and it can be applied without raising soil pH.
If the soil test indicates that calcium levels are at an optimum level, the addition of gypsum may not be beneficial, but it will not be harmful. However, if your soil test results indicate that the calcium levels are less than optimum, adding two to three tablespoons of gypsum can make a difference.
A couple more pointers will help you grow plants that thrive in acid soils.
Because of their high affinity for oxygen, they are extremely shallow-rooted. Mulch heavily and you’ll deprive them of oxygen.
Use fertilizers containing ammonium nitrogen, which is the form of nitrogen acid-loving plants absorb.