Extension News

Ask the ISU Extension Gardening Experts

Note to media editors: Got gardening questions? Contact the Iowa State University Extension 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.


Several of my onions are forming flower heads.  Why? 
Onions are grown from seeds, sets and plants.  Flowering is most likely to occur on onions grown from sets. Sets are small onion bulbs that were grown the previous year, harvested, stored through winter, then distributed to garden centers in early spring.

When purchasing sets, select bulbs that are smaller than a nickel in diameter. Sets larger than a nickel in diameter are much more likely to flower. Flowering plants are best used as green onions as they do not form good-sized bulbs.   

Are serviceberry fruit edible? 
The blueberry-like fruit of serviceberries (Amelanchier spp.) are edible. The fruit may be eaten fresh, baked in pies or other desserts, canned, or made into wine, jams or preserves.  Unfortunately, birds are quite fond of the fruit and often devour the berries as soon as they ripen. 

When should cherries be harvested? 
Sour or tart cherries should be harvested when the fruit are full-flavored, somewhat soft and juicy. Harvest sweet cherries when the fruit have attained the proper size, are uniformly colored and possess their characteristic flavor.

For immediate use, the cherries can be picked without the stems attached to the fruit. However, harvest the cherries with the stems attached if intending to store the fruit. Store cherries immediately after harvest. Place cherries in perforated plastic bags and store in the refrigerator at a temperature 32 to 35 degrees Fahrenheit. 

We recently experienced several days of flooding. What will happen to the trees in the yard? 
Flooding during the growing season typically is more harmful to trees than flooding during dormant periods. And, the longer trees are exposed to flooding, the greater the potential for injury. Short periods of flooding during the growing season can be tolerated by most trees, but if flooding is recurrent or uninterrupted and keeps soils saturated, serious damage to trees may occur.

Flood stressed trees exhibit a wide range of symptoms including leaf chlorosis (yellowing), defoliation, reduced leaf size and shoot growth, epicormic sprouting (sprouts along the stem or trunk) and crown dieback. Early fall coloration and leaf drop often occur and large seed crops may appear on stressed trees in the growing season after flooding. These symptoms may progress into tree decline and death, reoccur for several years and then eventually disappear or subside as early as the next year indicating rapid tree recovery. 


Contacts :

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

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