Extension News

Ask the ISU Extension Garden Experts: Perennials, Stinkhorns and Tomatoes

Note to media editors: Got gardening questions? Call the Hortline at (515) 294-3108, Monday-Friday from 10 a.m. to noon and 1 to 4:30 p.m., or e-mail us at hortline@iastate.edu. For more gardening information, visit us at Yard and Garden Online, http://www.yardandgarden.extension.iastate.edu

7/30/2009

How often should I divide perennials?

The frequency of division depends on the species of plant. Most fast growing perennials, such as daylily, hosta and bee balm, can be divided every three to five years. Perennials that spread rather slowly, such as Siberian iris and peony, can be divided every five to seven years. Some perennials, like false blue indigo and gas plant, don’t like to be divided and should be left undisturbed in the garden.

There are horn-shaped, foul-smelling objects growing in my mulched flower beds. What are they?

The foul-smelling objects are likely stinkhorns. Stinkhorns are a type of fungus or mushroom. The common name is derived from their appearance and smell. Stinkhorns usually appear in cool, wet periods in late summer and early fall.

Several species of stinkhorn are found in Iowa. The fungi live off dead organic matter and are commonly found in mulched areas in the landscape. Stinkhorns start off as an egg-like, golf ball sized structure in the soil. As the fungus develops, a stalk grows upward and is topped with a slimy cap coated with a mass of olive green to brown spores. The putrid smell of the stinkhorn cap attracts flies and other insects. The flies and other insects crawl on the stinkhorn, get covered with slime and spores, then fly away to other areas, disseminating the spores. Stinkhorns range from about four to eight inches in height.

Stinkhorns are not poisonous or harmful to plants or people. Eventually, the stinkhorns will wither away and disappear. Individuals can rake up and discard the fungi if their appearance or smell are bothersome.

Why are my tomatoes ripening so slowly?

Once fruit set has occurred, it normally takes 45 to 55 days for tomato fruit to fully develop and ripen. Cool temperatures during tomato fruit development will slow maturity. Tomato fruit may require an additional seven to 10 days to mature when daytime high temperatures are consistently in the 60s and 70s.

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Contacts :

Richard Jauron, Horticulture, (515) 294-1871, rjauron@iastate.edu

Del Marks, Extension Communications and External Relations, (515) 294-9807, delmarks@iastate.edu