Extension News

Ask the ISU Experts

Note to media editors:

Got gardening questions? Contact the Hortline at (515) 294-3108 (M-F; 10-12 & 1-4:30) 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


When should I remove the mulch from my strawberry planting? 

To reduce the chances of frost or freeze damage, leave the mulch on as long as possible. Removal of the mulch in March or early April may encourage the plants to bloom before the danger of frost is past. Temperatures of 32 degrees F or lower may severely damage or destroy open flowers. Since the first flowers produce the largest berries, a late spring frost or freeze can drastically reduce yields. 


To determine when to remove the mulch, periodically examine the strawberry plants in spring. Remove the mulch from the strawberry planting when approximately 25 percent of the plants are producing new growth. New growth will be white or yellow in color. (If possible, the winter mulch on strawberries should remain until mid-April in central Iowa.) When removing the mulch, rake the material to the aisles between rows.  If there is a threat of a frost later in spring during bloom, lightly rake the mulch over the strawberry plants. 


When is the best time to aerate a lawn? 

In Iowa, September and April are the best times to aerate Kentucky bluegrass and other cool-season lawns. While the overall results are beneficial, core aeration causes some initial damage. Aerating in September or April allows the grass to quickly recover during the favorable growing conditions in early fall and spring. 


Aerate the lawn when the soil is moist. If the soil is dry, the hollow tines of the core aerator won’t be able to penetrate to the proper depth. The tines of the aerator may get plugged when the soil is wet. 


I just received bare-root roses in the mail, but it’s too wet to plant them.  What should I do? 

Unpack and inspect the plants immediately upon delivery.  Dormant, bare-root roses are usually shipped with moist wood shavings or a similar material around their roots. If this material has dried out, lightly moisten it. Repack the roses and store them in a cool location, such as a garage or shed. Dormant roses stored in a cool location should be fine for several days. 


When should I fertilize my perennials? 

Early spring is the best time to fertilize perennials in Iowa.  Apply the fertilizer in April as new growth emerges from the ground.  For most perennials, an application of 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet is adequate. Excess fertilization promotes rampant, succulent growth and inhibits flowering. 



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.