Drench with a broad-spectrum fungicide at planting and again in 4 weeks. Use a broad-spectrum fungicide drench at planting. 30 ppm can be used for height control as they approach finished size. They can be cut back if they become overgrown the same way you would a verbena. High light plant.
Water stress can cause flowers to blast.
Drench with a broad-spectrum fungicide at planting and again 4 weeks later. 20 ppm are effective but generally not required. Drench with a broad-spectrum fungicide drench at planting. Somewhat elevated need for iron and magnesium. Thrips and water stress can lead to buds dropping before they open.