Make sure that organic matter added is well decomposed, or it may rob nitrogen from the geraniums as it decomposes. Through the growing season geraniums require fertilization every 4 to 6 weeks. Choose a fertilizer with a slow-release form of nitrogen to guard against leaching of nitrogen during heavy rains, which may damage ground and surface water quality, and to ensure a steady supply of nitrogen to the growing plants. Bed Preparation and Fertilization Recommendations for Bedding Plants in the Landscape for more information. Transplant geraniums after all danger of late frost is past in your area.
Geraniums are easy to transplant and establish quickly after soils are warm in the spring.
If bedding plants have a heavy, dense root ball, knock the potting mix out and break up the root ball before planting. Break up or remove peat pots, never letting the peat pot extend above the soil surface, as this wicks water away from the roots. Mulching with pine straw, pine bark chips or shredded hardwood bark mulch is recommended to conserve water in the soil and prevent splashing of soil onto plants during heavy rains, which may spread disease organisms. Apply mulch after the soil warms in the spring. 2-inch layer of mulch is adequate to reduce high soil temperatures during the summer, prevent soil crusting, improve aeration and reduce weed growth.