Cut a 3-to-5-inch growing tip from your geranium plant with at least two healthy leaves. Remove any foliage from the bottom 2 inches of the cutting.
Pour rooting powder in a disposable cup. This allows you to dip your cuttings in the powder without contaminating the powder in the original container.
Dip the bottom 1/2 inch of the cutting into the rooting powder. Tap the cutting on the rim of the cup to remove excess rooting powder.
Insert the cutting to a depth of 1 to 1 1/2 inches in a plant pot filled with moist potting medium. Perlite, sand or vermiculite work well for rooting geranium cuttings. Firm the potting medium around the stem of the cutting to secure it in the soil.
Cover the pot with a plastic food storage bag to hold in moisture. This keeps the soil moist and increases the humidity around the cutting. Cuttings root best in warm, humid conditions.
Place the cuttings in a warm location that receives bright, indirect sunlight. Although an eastern or northern window is desired, southern and western windows are suitable, as long as you avoid direct sunlight.
Check the soil every few days for drying. Water just enough to moisten the soil. Open the bag to increase air circulation and evaporation if the soil remains soggy or you notice signs of mold.
Tug gently on the cutting after two weeks to determine if roots have formed. If the cutting resists your efforts, roots have formed and can now be planted in the desired plant pots.
Gradually move the potted geraniums to direct sunlight. Begin fertilizing with all-purpose plant food when new growth appears. Follow the recommended application rate on the container.