Some growers think about calcium only to avoid the latter problem ignoring the former. This element moves into the plant with the water used for transpiration. Adequate levels of calcium early in the season, when temperatures and transpiration are high, will contribute in having adequate calcium levels in the plant tissues. Sometimes, calcium may be deficient despite the fact that it is present at levels considered to be acceptable in both soil and plant tissue. The deficiency may be caused by an excess of magnesium.
Poinsettias have higher molybdenum requirements than other crops.
Apply at least 0.1 ppm of this element throughout the whole poinsettia cycle using a soluble fertilizer that contains this micronutrient. Applications of this element can also be done through sprays. Fertilizer levels for dark leaf poinsettias. Poinsettia cultivars with dark foliage require less fertilizer levels than light foliage cultivars. Keep in mind that if the EC reaches levels below 1.2 mS cm -1, you should fertilize.