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


Are butterfly weed and butterfly bush different names for the same plant? 

Butterfly weed and butterfly bush are actually different plants. 
Butterfly weed (Asclepias tuberosa) is a herbaceous perennial. A member of the milkweed family, butterfly weed grows two to three feet tall and produces flat-topped clusters of bright orange flowers from July through September. The flowers attract several butterfly species, hence the common name. 
Butterfly weed is easy to grow. It performs best in full sun and tolerates drought and infertile soils. Because of its rather long taproot, transplanting the butterfly weed can be difficult. Carefully choose a site and don’t disturb it. Also, the butterfly weed emerges rather late in spring. To prevent possible injury, mark the planting site and don’t cultivate in the area until the plant emerges. 

The butterfly bush (Buddleia spp.) is a medium-sized, woody shrub. However, it’s generally regarded as a herbaceous perennial in Iowa because the shrub typically dies back to the ground each winter. Fortunately, the performance of the butterfly bush is not greatly affected by the extensive dieback. The butterfly bush grows back rapidly after the dead wood is removed in early spring and blooms on the current year’s growth. Plants generally have a loose, open, arching habit. By the end of summer, plants are often five to six feet tall. 

The butterfly bush produces flowers on dense, 6- to 12-inch-long spikes (panicles).  In Iowa, flowering typically begins in early summer and continues until frost. Flower colors include white, yellow, pink, blue, violet and purple. The fragrant flowers attract butterflies, hummingbirds and bees. 

Butterfly bushes perform best in moist, well-drained soils in partial to full sun. Avoid wet, poorly drained sites. Also, select sites that provide winter protection. 

There are black spots on the surface of my apples.  Can I eat the skins? 

The black spots are probably sooty blotch or flyspeck. Sooty blotch and flyspeck are two different fungal diseases that often occur together on apples. Sooty blotch appears as dark brown to black, 0.5 inch or larger smudges on the surface of the apple.  Flyspeck produces clusters of shiny, round, black dots. Individual dots are about the size of a pinhead. Environmental conditions that favor disease development are moderate temperatures and extended wet periods in late summer/early fall.

Sooty blotch and flyspeck live on the surface of the fruit.  Damage is mainly cosmetic.  The skins on the apples can be eaten; they just don't look very appetizing. 

Cultural practices and fungicides can help control sooty blotch and flyspeck. Proper pruning of apple trees and thinning of fruit promote drying and help reduce disease severity. Fungicides also may be necessary. 


Contacts :

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

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