Gerberas can be watered and fertilized overhead for about 4 weeks before they must be placed at final spacing. If a starter amount of fertilizer was added to the medium at mixing, do not begin fertilizing until roots reach the sides and bottom of the pot. Young plants should be fertilized with 100 to 150 ppm nitrogen for the first 2 to 3 weeks. This rate should be increased to 150 to 200 ppm nitrogen during the winter months or 200 to 250 ppm nitrogen during the summer months. Adjust the nitrogen application rate based on plant growth.
Excessive nitrogen can cause the foliage to overgrow and hide the flowers.
Growers should manage the fertility program for gerbera daisies by performing a soil test and tissue analysis at least once a month. Floral crop soil tests provide medium pH, soluble salts, and levels of macro- and micronutrients. Low readings often mean not enough fertilizer is being applied, application is too infrequent, or a combination of both. High readings may mean too much fertilizer is being applied, application is too frequent, not enough water is applied to wet the medium and obtain drainage, drainage is poor, or a combination of these conditions exists. Tissue analysis provides information about what nutrients are being absorbed by the roots and transported to the foliage.