This formula has a very high potential acidity. If used in a continuous feeding program, the pH should be monitored to ensure that it does not go below the desired level. It is recommended for crops such as azaleas, rhododendrons and many evergreens requring acid soil conditions. When irrigation water has a high pH, 21-7-7 will help to overcome the effect of the bicarbonate ions in the media and gradually reduce the pH for better growth of bedding plants, pot crops, cut flowers, and nursery stock in containers and in the field. |
