WHEN TO SET OUTSIDE
About a week after last frost, when nighttime temperatures remain above 50°F.
PLACEMENT & CULTIVATION
Geraniums traveled from South Africa and were cultivated and marveled over in early glasshouses of the 1600s, and we love them still for their varied beautiful leaves and flower colors. Provide well-drained soils and allow the soil to dry before watering thoroughly. Deadhead spent flowers regularly and provide some afternoon shade in hot summer areas, for they do best in low humidity, cool to moderate summer areas. 'Old Scarlet Unique' blooms better than regal types in the often hot and dry weather of summer. Trim to shape right after bloom ends in summer and leave potted plants outdoors until temperatures drop into the 40-45°F range, hopefully exposing them to six weeks of cool night temperatures. Bring them into a cool room, around 60°F, to overwinter, and their gorgeous blooms will start to unfold in late winter.
Watering Details:
Water when soil is dry 2" down into pot. Geraniums suffer if the soil stays saturated with water, so water only after soil has dried.
Fertilizer:
Fertilize twice a month with a balanced formulation such as 15-15-15.
Diseases & Pests:
Aphids and mealybugs can be troublesome; if detected, treat with an insecticidal soap or neem oil. Avoid botrytis or gray mold by spacing properly, not wetting the foliage when watering, and keeping dead plant material, such as spent flowers and leaves, cleaned up.