Extension News

Ask the ISU Extension Gardening Experts

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


Can the seven-son flower be successfully grown in Iowa?

The seven-son flower (Heptacodium miconioides) is a large shrub or small tree that grows 15 to 20 feet tall. The plant produces clusters of fragrant, creamy white flowers in late summer. After flowering, fruits develop that turn purplish red in October. The attractive fruits persist for two to three weeks.

The seven-son flower is not cold hardy in northern Iowa, but it can be successfully grown in the southern half of the state (USDA Hardiness Zone 5). It performs best in well-drained soils in full sun.

What would be a good planting site for strawberries?

Strawberries require full sun and well-drained soils. The planting site should receive at least six hours of direct sunlight per day. Leaf and root diseases often are problems in poorly drained, wet soils. When selecting a site for the strawberry planting, do not plant in ground that is heavily infested with perennial weeds, such as quackgrass. Weed control will be extremely difficult. Also, avoid sites where strawberries, tomatoes, potatoes and peppers have been grown within the last three years to minimize the risk of Verticillium wilt and other root diseases.

What are some good switchgrass varieties for the home landscape?

Switchgrass (Panicum virgatum) is a native prairie grass. It is typically found in moist sites, such as along the banks of streams, and grows three to six feet tall.

Several switchgrass cultivars are excellent plants for the home landscape. ‘Heavy Metal’ is a dense, upright plant with metallic blue foliage. Plants grow three to five feet tall. ‘Dallas Blues’ grows five feet tall and has one-inch-wide, blue-green foliage. It turns tan to rust brown in fall. ‘Northwind’ is a dense, columnar plant that grows four to five feet tall. Its olive green foliage turns to yellow or beige in fall. ‘Shenandoah’ is a compact, three-foot-tall plant. Its foliage is initially bluish green, but turns to burgundy red by early summer. Finally, ‘Rehbraun’ grows three to four feet tall. Its medium green foliage turns reddish brown in fall.

Switchgrasses are easy to grow in the home landscape. They perform best in full sun and a well-drained, moist soil. They require little care and have few insect and disease pests.


Contacts :

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

Del Marks, Extension Communications and External Relations, (515) 295-9807, delmarks@iastate.edu