The common geranium (Pelargonium x hortorum) is a tender, flowering perennial that is often grown as a container plant, but can be grown as a shrub that will reach 3 feet in height. Geraniums thrive in lots of sunshine but require extra water during periods of hot weather. Propagation by cuttings is easy from cuttings taken in spring or summer.
Cut a stem from the geranium. It should be 2 to 3 inches in length and cut from the growing tip of the stem.
Pour vermiculite into the planting pot, and water it until the water runs from the bottom of the pot. Allow the water to drain completely. Use your finger to create a planting hole for the cutting.
Remove the leaves from the bottom two-thirds of the cutting.
Dip the cut-end of the stem into the rooting hormone and then stick it, 1-inch deep, into the vermiculite. Pack the vermiculite around the cutting, pressing on the medium to ensure good contact with the cutting.
Water the vermiculite again, allow the pot to drain and place the pot on the heat mat set at 75 degrees Fahrenheit. Ideally, the pot should be placed in a north or east window. Water when the top 1/2 inch of soil is dry.
Test the cutting by gently tugging on it. If the cutting resists, it is rooted. It generally takes three to four weeks for the cutting to root.
Fertilize the geranium cutting six weeks after planting it. Use a liquid 20-20-20 formula, diluted to half the strength recommended on the fertilizer label.
Harden off the cutting, two weeks after the first fertilizer application, by placing it outdoors and in the sun for one hour on the first day and longer periods of time each day, over the course of one week. Once acclimated to the outdoor environment, the geranium can be planted or placed in its permanent location.