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. - 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


Is rhubarb safe to eat after the plants have been exposed to freezing temperatures? 


Temperatures in the upper 20s and low 30s usually don’t harm rhubarb. Gardeners should examine their rhubarb after a freeze and base their decision on plant appearance.  Rhubarb leaves damaged by freezing temperatures will shrivel and turn black. Damaged stalks become soft and mushy. Damaged rhubarb stalks should be pulled and discarded. Any new growth that emerges later in spring should be safe to eat. Rhubarb plants showing no sign of damage are fine and can be harvested. 


Can muskmelons be started indoors? 


For an earlier crop, muskmelons can be started indoors.  Sow seeds indoors three to four weeks before the anticipated outdoor planting date.  Muskmelons can be planted outdoors in early May in southern Iowa, mid-May in central Iowa, and late May in northern portions of the state.  Muskmelons and other vine crops are somewhat difficult to transplant.  When starting vine crops indoors, sow seeds in peat pots, peat pellets (Jiffy-7s) or other plantable containers.  Muskmelon seedlings grown in plantable containers suffer little damage during the transplanting process.  As a result, transplanting success is usually high.  Sow three to four seeds per container.  Later, remove all but two seedlings.  Transplant the seedlings outdoors when plants have one or two true leaves.  Prior to planting, harden (acclimate) the seedlings outdoors for a few days in a shady, protected location to lessen transplant stress. 


How high should I mow my lawn in spring? 


Mow Kentucky bluegrass lawns at a height of 2.5 to 3 inches in spring.  When mowing the lawn, remove no more than one-third of the total leaf area at any one time.  For example, if the lawn is being mowed at a height of 3 inches, the grass should be cut when it is 4.5 inches tall.  Depending on weather conditions and fertilization practices, it may be necessary to mow bluegrass lawns every four to five days in spring. 


What are some good raspberry varieties for Iowa? 


Suggested summer-bearing red raspberries for Iowa include ‘Boyne,’ ‘Latham,’ and ‘Killarney.’  ‘Heritage,’ ‘Redwing,’ and ‘Autumn Bliss’ are excellent fall-bearing red raspberries. The best purple raspberry varieties are ‘Brandywine’ and Royalty.’ Black raspberries are not reliably hardy in northern Iowa. Gardeners in central and southern Iowa can choose from ‘Black Hawk,’ ‘Bristol,’ and ‘Jewel.’ ‘Fall Gold’ is an excellent fall-bearing yellow raspberry.



Contacts :

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

Jean McGuire, Continuing Education and Communication Services, (515) 294-7033, jmcguire@iastate.edu

There are no photos for this week's column.