Boasting good branching and a mounding habit, growers will also appreciate the heat and cold resistance of Empress verbena. ‘Empress Soft Pink Charme’ and ‘Empress Dark Red Charme’ feature unique coloration with white centers.
Use a good rooting medium with a well-aerated soil structure. After sticking, water the cuttings uniformly for a good soil-to-stem connection. Temperatures should be maintained between 65 and 75° F day and night. To enhance and promote uniform root development, apply bottom heat at 72 to 75° F.
Grow at 65 to 75° F during the day and 60 to 65° F at night with good circulation. Optimum light level is 5,000 to 6,000 foot-candles.
Alternate liquid feed of 200- to 300-ppm 15-0-15 and 20-10-20. Excess ammonium may cause soft growth and internode stretch. Leach regularly to maintain an EC of 1.5 to 2.0. Verbena is sensitive to both drying out and being too wet; manage water and humidity to reduce occurrences of diseases like Botrytis gray mold.
A hard pinch (above the fourth or fifth set of leaves) once plant roots reach the edge of container will promote basal branching. Additional pinching will improve plant fullness.