Propagating Geraniums Using Stem Cuttings
Master Gardener Scoop – January 10, 2018

By Jeanette M. Endres,
Master Gardener

Christmas poinsettias and cacti are still blooming but it is time to think of spring and propagating flowers for the spring master gardener plant swap.
I brought two large geranium plants in the house to overwinter in a bright sunny window.
They are proving good material for propagating new plants. The geraniums we buy for bedding plants and those that can be easily propagated from cuttings are from the family Geraniaceae . Pelargoniums are known botanically as geraniums.
There is no particular time of the year to take cuttings, because they have no dormancy and grow for twelve months of the year. Some gardeners believe the best time to take cuttings is early spring and later summer, but with the right conditions, any time can result in healthy cuttings.
Early cuttings, the ones you take now, should flower this summer, while later cuttings will provide larger plants ready to flower the following summer. Flowering usually begins two to four months after the cuttings have roots.
I use one part peat moss to two parts vermiculite by volume for the sterile material. Some gardeners use sterile sand or vermiculite alone.
Sterile rooting mixes include peat, sand, perlite or a combination of these materials. They are light and porous while allowing good moisture retention and airflow to the developing roots.
Use containers that are clean and will provide some moisture. I use a 4-5inch deep flat with good drainage, and keep the temperature around 68-70 degrees. If you want to try only a few cuttings the University of Illinois (Master Gardner Manual Edition 2, 2014) suggests a 6 “clay pot with drainage hole covered.
Fill half of pot with moistened vermiculite and insert a small clay porous 2-3” pot with drainage hole clogged using a cork or other waterproof material. Insert the small pot into the middle of the larger pot.
Fill and moisten vermiculite in large pot.
Fill the smaller pot with water.
Insert cuttings around the small pot and as the vermiculite dries out, water from small pot will keep vermiculite moist.
Take cuttings from a geranium stalk that are not blooming. Roots grow from leaf nodes, areas on the stalk where the leaf bud emerges.
Take stem cuttings about 3- 4 inches long. Cuts should be made about ¼” below a node. Remove all leaves from the lower 1 ¼ inches of the stem. The lower 1” of the stems can be dusted with a root hormone.
I have equal success using or not using a root hormone.
It will take three to four weeks for roots to develop. Do not let plants dry out and keep them in a lighted, dry atmosphere.
I use a heat mat and supply moisture weekly but do not cover the plants, since they are very prone to rotting in high humidity.
Be prepared to transplant cuttings to a potting soil when roots have developed since sterile rooting mixtures will not sustain the plants.
It is a good idea to start on the regal varieties (Martha Washington) first, since they take longer to root and longer to come into bloom than the zonal types that are the typical bedding plants.
If you have never tried propagating geraniums before, then try it.
I still get a thrill when fresh, white roots are coming out of the base of a geranium cutting.
For more information, contact your local University of Illinois Extension Office.