fertilizer

Calcium is not mobile within the plant. So the plant relies on the process of transpiration in which the plant roots take up the soil solution (which contains the needed calcium), transports it to new growth where the calcium is used and the excess water vapor escapes out through holes in the leaves called stomata. Anything that slows transpiration, such as high humidity or cold temperatures, can induce calcium deficiency even if the calcium levels are normal in the growing medium. Parts of the plant that transpire little water, i.e. young leaves and fruit, will display calcium deficiencies first. Blossom end rot of tomatoes is a classic case of calcium deficiency. Calcium deficiency can arise if levels in the fertilizer solution are less than 40-60 ppm and/or potassium, magnesium, or sodium levels are too high.

Nitrogen plays an important role in photosynthesis and fuels rapid growth. It helps build energy to keep plants growing strong and stimulates vigorous foliage and stems. Plants with sufficient nitrogen reflect a healthy, deep green color. Nitrogen-deficient plants may be stunted and show yellowing, called chlorosis, on the leaves. High nitrogen directs the plant’s energy into vegetative growth instead of flowering and fruit. Applied late in the year, it encourages vulnerable new growth and delays a plant’s entry into winter dormancy.