Fertilizing should be done from mid-April to mid-July only, with the exception of a very late fall application if desired. Because the plant needs to slow down its growth in August and September, it does not need any extra nitrogen at that time. When fertilizing, remember that the highest needs occur during the most vigorous growth period. This period coincides with the most heat and moisture, usually mid-May to mid-July.
Yellowing of leaves is very common to see on several varieties of plants. Yellowing can occur for several reasons. The plant may be too wet or too dry. The third reason is lime-induced iron Chlorosis. Too wet or too dry can be identified by the leaves being uniformly pale yellow and starting at the center of the plant, not fresh growth. Iron Chlorosis can be identified by leaves of fresh growth being yellow but the veins remaining green. It is most evident in July. Iron Chlorosis can be resolved with an application of iron or sulphur. Sulphur has proven to be the most economical solution.