Pelargonium geraniums, also known as zonal geraniums, have been in cultivation since the early 1700s. Originally developed in England, Germany is now the leading supplier of commercial geraniums. There are hundreds of varieties available worldwide and new cultivars are introduced every year. Available in a variety of flower and leaf colors, popular, easy-to-grow geraniums are pest- and drought-resistant, tolerant of limited sunlight and have a long growing season.
Select pots that are at least twice the size of the original nursery containers.
Disinfect pots before planting. Scrub the interiors with a mixture of 1 part bleach to 9 parts water. Rinse well.
Use a sterile, commercial potting mix. Place a piece of screen across the drainage hole of the pot and add several inches of potting soil to the pot. Gently remove the plant from its nursery container and add it to the pot. Do not cover the plant's original soil line---the transplant should be at the same height as it was in its previous pot. Fill the voids in the pot and tamp the soil down firmly. Water thoroughly.
Place the plants in a location that gets at least 4 hours of sun. In regions north of zone 6, geraniums can tolerate 6 or more hours of sun.
Water geraniums thoroughly when the top 1 inch of the soil mix is dry to the touch. Keep a regular schedule of watering--geraniums do not wilt or show signs of distress when they need water.
Fertilize geraniums every third watering. Use a water-soluble 10-10-10 fertilizer.
Trim off spent flowers regularly and remove any damaged or dying leaves.