Hollyhocks (Alcea rosea) sport colorful flowers on tall stems and are often grown against fences and outbuildings. Alcea spp. are hardy in U.S. Department of Agriculture zones 3 to 10, although the most common species, A. rosea, prefers zones 3 to 8. Considered both perennial and biennial (blooming the second year), hollyhocks hate being moved and are easily propagated by collecting seeds. However, plants can also be started with a careful cutting of the root.
Test your soil's acidity level before planting; hollyhocks prefer soil with a pH of 6 to 8 to thrive, although they can survive in other soils. A pH of 7 is considered neutral soil; below this the soil is acidic, and above it the soil is alkaline. The pH can be raised or lowered, depending on your reading, by adding various nutrients as recommended on the test kit packaging to bring balance.
Use a sharp spade to dig under the hollyhock and expose the roots when the plant is dormant from November through February. It is best to avoid doing this when temperatures have dipped extremely low, both to protect the plant and dig up the ground with relative ease.
Cut a 3- to 4-inch length of healthy root from the hollyhock with a sharp knife or scissors; the end closest to the root ball should be cut straight across. The root should be 1/4 inch wide or larger. Avoid any blackened roots; the dark color indicates they are dead or dying. Push the hollyhock's remaining root ball back into the ground, and cover it with the spaded-up soil.
Make a diagonal cut on the other end of the root before placing it in rooting medium in a planting container. Place the container in a cool, dark place for at least three weeks; this mimics dormancy in the ground.
Plant the cutting -- which should be showing roots -- in a planter filled with potting soil. Water the soil and keep it moist.
Place the planter in a warm indoor location with bright sunlight until the hollyhock is several inches tall and can be transplanted outdoors as the weather permits.
Things You Will Need
- Soil test kit
- Knife or scissors
- Rooting medium
- Potting soil
- Watering can
- Several root cuttings may be taken if you wish to propagate more than one hollyhock at a time.
- Shovels are not sharp enough to make a clean cut through roots and may tear or damage the root ball of the Hollyhock you are cutting.
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