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71  Apply 220 lbs Epsom salts (magnesium sulfate) per acre or a fertilizer containing magnesium.  (When lime is not recommended and soil test magnesium is low)

73  Apply 2,200 lbs gypsum per acre  (When lime is not recommended and soil test calcium is less than 400 lbs calcium per acre)

300  As a precaution against fertilizer burn, water the plants immediately after the fertilizer is applied. 

308  Uniformly spread fertilizer over area beginning 6 inches from the trunk and extending well beyond end of branch spread.  Not necessary to remove the mulch before applying the fertilizer.  Brush or rinse the fertilizer from the leaves and stems.  Always use an azalea/rhododendron fertilizer, such as that containing ammonium sulfate to help lower pH.

315  If plants show iron deficiency symptoms (yellow tissue between green veins on upper leaves), apply chelated iron following label directions for the material used, or apply a 2% solution of ferrous sulfate including a surfactant applied at a rate of 120 to 180 gallons per acre.  Apply the iron-containing solution to the foliage in the late afternoon when the air temperatures are warm and only to plants that are being adequately watered and fertilized.    (Recommendation when soil pH is greater than 6.0)

323  Uniformly spread fertilizer over the area and soak into the soil.  If applied before planting, mix in the top 6 inches.

325  Soil pH too high for acid-loving plants.  To lower the soil pH, apply 900 lbs elemental sulfur per acre.  Increase the recommended rate by one-half for clay soils and reduce it by one-third for sandy soils.  If aluminum sulfate is used to lower the soil pH, use seven times the above recommended rate as that for elemental sulfur.  Take a second soil sample after several weeks to check its pH before applying additional material needed to lower the soil pH.  When applying elemental sulfur, mix with builder’s sand for easier spreading.  Caution – sulfur dust may irritate the eyes.  (When soil pH is greater than 6.0 and less than 6.6)

326  Soil pH too high for acid-loving plants.  To lower the soil pH, apply 1,300 lbs elemental sulfur per acre.  Increase the recommended rate by one-half for clay soils and reduce it by one-third for sandy soils.  If aluminum sulfate is used to lower the soil pH, use seven times the above recommended rate as that for elemental sulfur.  Take a second soil sample after several weeks to check its pH before applying additional material needed to lower the pH.  When applying elemental sulfur, mix with builder’s sand for easier spreading.  Caution – sulfur dust may irritate the eyes.  (When soil pH is greater than 6.5 and less than 7.1)

327  Soil pH too high for acid-loving plants. To lower the soil pH, apply 1,700 lbs elemental sulfur per acre.  Increase the recommended rate by one-half for clay soils and reduce it by one-third for sandy soils.  If aluminum sulfate is used to lower the soil pH, use seven times the above recommended rate as that for elemental sulfur.  Take a second soil sample to check its pH before applying additional material needed to lower the pH.  When applying elemental sulfur, mix with builder’s sand for easier spreading.  Caution – sulfur dust may irritate the eyes.  (When soil water pH is greater than 7.0 and less than 7.6)

328  Soil pH too high for acid-loving plants.  To lower the soil pH, apply 2,100 lbs elemental sulfur per acre.  Increase the recommended rate by one-half for clay soils and reduce it by one-third for sandy soils.  If aluminum sulfate is used to lower the soil pH, use seven times the above recommended rate as that for elemental sulfur.  Take a second soil sample to check its pH before applying additional material needed to lower the soil pH.  When applying elemental sulfur, mix with builder’s sand for easier spreading.  Caution – sulfur dust may irritate the eyes.  (When soil water pH is greater than 7.5)