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.

9/19/2007

What would be a good planting site for crocuses?
Crocuses perform best in well-drained soils in partial to full sun.  Plant crocuses in clusters of 25 or more corms for maximum visual impact. Good garden sites include perennial flower beds, rock gardens and among low-growing groundcovers. (Do not plant crocuses in the lawn. The grass will have to be mowed before the crocus foliage has died down.) Plant corms approximately 3 inches deep and 3 to 4 inches apart. 

What are the black spots or blotches on my apples? 
The problem may be sooty blotch and 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 apples are still safe to eat. They’re just not very attractive. 

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. 

If control measures fail, sooty blotch and flyspeck can be removed with vigorous rubbing. 

I would like to attract birds to my yard.  Which trees and shrubs provide food for birds in the fall? 
When attempting to attract birds to the landscape, trees and shrubs that provide food during fall are important. Fall foods allow birds to build up their food reserves for the difficult months ahead. (These foods often remain available into winter if not consumed in the fall.) The following trees and shrubs provide food for birds during the fall months.  

Blackhaw viburnum (Viburnum prunifolium) is a large, multi-stemmed shrub or small tree that grows 10 to 15 feet tall. Blackhaw viburnum produces creamy white flowers in flat-topped, 2- to 4-inch-wide clusters in spring. The berry-like fruit turn bluish black at maturity and are a good food source for birds in fall and early winter. The foliage of blackhaw viburnum is dark green in summer changing to purple or reddish purple in the fall. 

The bright red fruit of winterberry (Ilex verticillata) are a beautiful sight in fall.  Winterberry is a deciduous holly. Like other hollies, it’s dioecious which means that male and female flowers are produced on separate plants. The small, inconspicuous flowers are produced in spring. The rounded, 0.25 to 0.5 inch in diameter, berry-like fruit on female plants turn bright red in early fall. Hungry birds usually devour most of the fruit by early winter. Two female varieties noted for their heavy fruit displays are ‘Sparkleberry’ and ‘Winter Red.’ A male variety, such as ‘Southern Gentleman,’ must also be planted for pollination and fruit set. Winterberry prefers moist, acidic soils and will grow in full sun to partial shade. It commonly grows 6 to 8 feet tall. 

Oaks (Quercus species) are long-lived, durable trees that are often planted as shade trees. Commonly planted oaks include the red oak (Quercus rubra), white oak (Quercus alba), swamp white oak (Quercus bicolor) and bur oak (Quercus macrocarpa). Oak acorns are important sources of food from fall into winter for gamebirds, such as turkeys, pheasants and quail, plus blue jays, nuthatches and several woodpecker species. 

The eastern wahoo (Euonymus atropurpureus), hazelnut (Corylus americana), and cotoneasters (Cotoneaster species) are other woody plants that provide food for birds in the fall. 

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Contacts :

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

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