Extension News

Ask the ISU Experts

Note to media editors: Got gardening questions? Contact the Hortline at (515) 294-3108 (Monday-Friday; 10 a.m.-12 Noon and 1-4:30 p.m.) or send an e-mail to hortline@iastate.edu. For more gardening information visit us at Yard and Garden Online at www.yardandgarden.extension.iastate.edu.


What is the name of the roadside grass that produces silvery-white plumes in late summer?
The grass that has become naturalized in roadside ditches and waste areas in the Midwest is Miscanthus sacchariflorus.  Common names for Miscanthus sacchariflorus are Amur silver grass, silver plume grass, silver banner grass, hardy pampas grass and others. While the silvery-white plumes of Miscanthus sacchariflorus are attractive, planting it is not recommended because of its invasive nature.  Miscanthus sinensis ‘Silberfeder’ (silver feather grass) is an excellent choice for home landscapes. Silver feather grass is an upright, clump-forming grass that grows to a height of 6 to 8 feet. Large silvery-white flower heads are produced in late summer and are borne high above the foliage. Miscanthus sinensis ‘Silberfeder’ is not invasive. 

When would be the best time to transplant a rhododendron? 
Rhododendrons are broad-leaved evergreens. Early spring (before the shrubs begin to grow) would be the best time to transplant rhododendrons. Rhododendrons have shallow, fibrous, wide-spreading root systems. Carefully dig up the rhododendron, retaining as much of the root system as possible.  Replant immediately. Rhododendrons require well-drained soils with a soil pH of 4.0 to 5.5. 

How do I harvest and cure hickory nuts? 
Hickory nuts mature in late summer/early fall. The husk, which is in sections, usually separates from the nut when it drops to the ground. Collect the nuts as soon as possible after they drop.  When collecting the nuts, carefully inspect the shells. Nuts with tiny holes in their shells have been damaged by the pecan/hickory weevil and should be discarded. Dry or cure the nuts by spreading them out in a thin layer in a cool, dry, well-ventilated location. Dry or cure the nuts for two to three weeks. After drying, crack the nuts and store the nutmeats in a closed container in the refrigerator. 

Will rosemary survive the winter outdoors? 
Rosemary (Rosmarinus officinalis) is a woody shrub in areas with mild winters. In Iowa, rosemary is regarded as a tender perennial as it will not survive the winter outdoors. However, it is possible to overwinter container-grown plants indoors. Potted rosemary plants should be brought indoors before the first frost in fall.  Place the plants in a sunny south or west window.  If window space is limited, rosemary should be placed under artificial light. Keep the plants on the dry side. When watering, water thoroughly. Some water should flow through the potting soil and out the bottom of the pot. Discard the excess water.  Allow the potting soil to dry nicely before watering again. Rosemary is a rather finicky plant. It sometimes fails to survive the winter indoors despite our best efforts.


Contacts :

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

Jean McGuire, Extension Communications and Marketing, (515) 294-7033, jmcguire@iastate.edu