For the Gardener:
In areas with alkaline soil and water, Surfinia petunias may require an iron supplement. Amendment of the soil to reduce the pH is beneficial. Iron deficiency is most likely the problem if the leaves become yellow.
For the Commercial Grower:
Most well draining potting mixes with good capacity to hold water will give excellent results.
The suggested pH range for organic medias and soils is between 5.8 and 6.8.
