Azaleas (Code #080)
Soil Test Rating
All Soils
Potassium

Low K

0-150 lbs/A

Medium K

151-250 lbs/A

High K

251-450 lbs/A

Very High K

450+ lbs/A

PhosphorusSee Comments

Low P

0-50 lbs/A

161161162162

Medium P

51-100 lbs/A

161161162162

High P

101-200 lbs/A

163163164164

Very High P

200+ lbs/A

163163164164

Recommendations:

Recommended pH:5.0 to 5.5. If the pH is less than 5.0, see Lime Table D and the soil depth adjustment table that immediately follows the lime tables.
Magnesium:

If soil test Mg level is low and lime is recommended, use dolomitic limestone.

Coastal PlainLow: 0 - 60 lbs/acre Medium: 61 - 120 lbs/acre High: >120 lbs/acre
Piedmont Low: 0 - 120 lbs/acre Medium: 121 - 240 lbs/acre High: >240 lbs/acre
Other:If soil pH is greater than 6.0, see Fact Sheet.

Comments:

Fifty pounds of limestone per 1000 square feet is equivalent to 5 pounds (6½ cups) per 100 square feet. (If lime recommendation is greater than 50 pounds per 1000 square feet, increase the per cup rate proportionately.)

161.

Apply 10-10-10 fertilizer at a rate of 1/4 cup per 10 square feet (2 cups per 100 square feet). If the fertilizer contains minor elements like manganese and zinc, it is preferred. Two-thirds of the fertilizer should be applied immediately after bloom when growth is most active and the remaining one-third applied in mid-June. Uniformly spread the fertilizer underneath the canopy and extending beyond the dripline of the foliage. It is not necessary to remove the mulch before applying the fertilizer. Brush or rinse the fertilizer from the leaves and stems. Irrigate after application.

162.

Apply 0-20-0 at a rate of 1 cup per 100 square feet immediately after bloom. If 0-20-0 is not available, apply 0-46-0 at a rate of 1/2 cup per 100 square feet. Also, per 100 square feet, apply 1/2 cup of 34-0-0, or 1/3 cup of 46-0-0, or 1 cup of 21-0-0. Two-thirds of the fertilizer should be applied immediately after bloom when growth is most active and the remaining one-third applied in mid-June. Uniformly spread the fertilizer underneath the canopy and extending beyond the dripline of the foliage. It is not necessary to remove the mulch before applying the fertilizer. Brush or rinse the fertilizer from the leaves and stems. Irrigate after application.

163.

Apply 15-0-15 fertilizer at a rate of 1¼ cup per 100 square feet. If these analyses are not available, substitute a 16-4-8 or 12-4-8 analysis. If the fertilizer contains minor elements like manganese and zinc, it is preferred. Two-thirds of the fertilizer should be applied immediately after bloom when growth is most active and the remaining one-third applied in mid-June. Uniformly spread the fertilizer underneath the canopy and extending beyond the dripline of the foliage. It is not necessary to remove the mulch before applying the fertilizer. Brush or rinse the fertilizer from the leaves and stems. Irrigate after application.

164.

Only nitrogen fertilizer is needed at this test level. Per 100 square feet, apply 1/2 cup of 34-0-0, or 1/3 cup of 46-0-0, or 1 cup of 21-0-0. Two-thirds of the fertilizer should be applied immediately after bloom when growth is most active and the remaining one-third applied in mid-June. Uniformly spread the fertilizer underneath the canopy and extending beyond the dripline of the foliage. It is not necessary to remove the mulch before applying the fertilizer. Brush or rinse the fertilizer from the leaves and stems. Irrigate after application.

Fact Sheet:

If the soil pH is 6.0 or greater, apply 1/2 cup of wettable sulfur per 10 square feet. Apply evenly out to and slightly beyond the dripline. Work into the soil surface, then water. If sulfur contacts foliage, wash it off immediately after application. On soils where the soil pH is 6.0 or greater and/or where plants show iron (Fe) deficiency symptoms (yellowing of the upper leaves between the veins with the veins remaining green), apply chelated iron following directions on the label.