Growing Geraniums - May 25, 2005
Jeff Schalau, County Director, Associate Agent, Agriculture & Natural Resources
Arizona Cooperative Extension, Yavapai County
Geraniums (Pelargonium sp.) are one of the most popular flowering plants. They are grown as bedding plants, perform well as both bedding plants and potted plants, and can be easily as house plants if given a sunny location. Geraniums will bloom all summer long given the right care. They can tolerate periodic dry periods, survive in any well-drained soil, and are virtually insect-free. Geraniums come in a variety of shapes and sizes, various scents, and are easy to propagate from cuttings. All of these attributes also make it an ideal plant for beginning gardeners.
Geraniums are available in nurseries and garden centers right now. These have usually been grown from cuttings and should be in full bloom. If growing them in the ground, prepare the soil by tilling in organic matter (compost, peat, or partially rotted manure), a complete fertilizer high in phosphorus, and some soil sulfur if you are on limestone soils. Plant no deeper than the container and irrigate regularly for best bloom. Removing spent flowers (deadheading) will increase flower production. Geraniums are perennials, but will freeze with our winter temperatures.
Zonal geraniums have thick stems, velvety leaves with dark spots, and are prolific flower producers. The flowers come in many bright colors ranging from vibrant reds to pinks and salmons. Zonal geraniums are very popular as bedding plants.
Ivy-leafed geraniums have thinner, trailing, stems and flowers tend toward pastel colors. These do not perform as well in the heat (above 85 degrees F). Ivy-leafed geraniums grow well in hanging baskets and window boxes with north or east exposures.
Scented geraniums have become very popular and come in a variety of scents including rose, lemon, mint, nutmeg, and peach. Some of these are grown for their essential oils. The flowers are interesting but not significant. These plants are grown primarily for foliage/scent and not so much for flowers. A special scented geranium is being marketed as the “mosquito plant”. The volatile oil produced is citronella. There are two past Backyard Gardener columns about scented geraniums (July 28, 1999 and August 4, 1999) which are archived on the Backyard Gardener web site.
Once established, you may start additional plants from cuttings. To do this, cut 3-4 inch stems using a clean, sharp blade such as a single edge razor blade. Strip off the lower leaves and stick them one to two inches deep into a 50:50 mixture of peat and perlite (or a soilless potting mix). Dipping cuttings in a rooting hormone can speed up the process and increase rooting success. Water thoroughly after sticking but keep soil on the dry side thereafter. Place them in a bright window or protected location until rooted. Cuttings should have new roots within four weeks. Making cuttings at the end of the growing season and bringing them indoors is the best way to carry geraniums through the winter.
Geraniums are relatively disease free in our area, but can be somewhat disease prone in more humid areas. Root knot nematodes are not native to our area, but where they have been introduced, can cause decline in geraniums. As mentioned previously, insect problems are not common with geraniums. Spider mites and whiteflies could impact geraniums in greenhouses or other special situations.
If you are new to gardening, geraniums can act as training wheels. You will learn how to plant, fertilize, and grow cuttings on a plant species that is very forgiving. Once successful, you can transfer these skills to other more finicky plants.
The University of Arizona Cooperative Extension has publications and information on gardening and pest management. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at email@example.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/.
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Last Updated: May 19, 2005
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