Extension News

Ask the ISU Extension Garden Experts: Safety of planting currants and gooseberries

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 send an e-mail to hortline@iastate.edu. For more gardening information, visit us at Yard and Garden Online, http://www.yardandgarden.extension.iastate.edu.

3/10/2010

Is it safe to plant currants and gooseberries in home gardens in Iowa?

Early in the 1900s, white pine blister rust (Cronartium ribicola) became a serious disease problem in the United States. White pine blister rust requires both a currant or gooseberry (Ribes species) and white pine to complete its life cycle. The disease causes little harm to currants and gooseberries, but is often deadly to white pines (black currants are very susceptible to white pine blister rust; gooseberries and red and white currants are somewhat resistant). In an attempt to prevent the spread of white pine blister rust, the federal government banned the planting and cultivation of currants and gooseberries early in the 20th century. The federal government lifted the ban in 1966. In recent years, several white pine blister rust resistant black currant varieties have been introduced. Rust-resistant black currant varieties include ‘Ben Sarek,’ ‘Consort,’ ‘Coronet,’ ‘Crusader’ and ‘Titiana.’

A site near a wooded area with large numbers of white pines would not be a good location for gooseberries and currants. However, there shouldn’t be serious problems planting currants and gooseberries in most home gardens. If planting black currants, be sure to select white pine blister rust resistant varieties.

When would be the best time to divide ‘Autumn Joy’ sedum?

Early spring is the best time to divide ‘Autumn Joy’ and other upright, clump-forming varieties. Dig up the perennials in early spring just as new growth begins to appear. Divide each clump into sections with a sharp knife. Each division should contain several shoots and a portion of the root system. Replant the divisions immediately. Sedums perform best in well-drained soils in full sun.

What are some important considerations when selecting a shrub for a hedge?

Home gardeners should carefully consider their landscape needs and the characteristics of the various shrubs. For example, deciduous shrubs drop their leaves in the fall and are effective screens mainly during the growing season. Evergreens provide good screening all year. Individuals considering a sheared, formal hedge should realize that they may need to be pruned (sheared) several times a year to remain attractive. In comparison, an informal, natural hedge is relatively low maintenance. Select shrubs that grow to the desired height. Planting a tall-maturing shrub where a short, informal hedge is desired creates unnecessary work. Another important consideration is ornamental characteristics. Some shrubs possess attractive flowers, fruit or foliage. Finally, make sure the shrub grows well in your area and has no serious insect and disease problems.

Contacts :

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

Christopher Weishaar , Extension Communications and External Relations, (515) 294-1327, cweishaar@iastate.edu