Extension News

Ask the ISU Extension Garden Experts: Beetles, Grass Seed and Gourds

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

8/21/2009

Can I reduce next year’s Japanese beetle population by applying an insecticide to my lawn? 

Adult Japanese beetles feed on the flowers, foliage and fruits of more than 300 different kinds of plants. Adults lay eggs in July and August in grassy areas. These eggs hatch into white grubs that feed on plant roots and organic matter in the soil. The grubs remain in the soil until the following June when they transform to new adults and emerge from the soil to start the cycle over. 

Female Japanese beetles lay their eggs in grassy areas over a large area (not just your lawn).  Treating your lawn with an insecticide will not reduce the Japanese beetle population next year as adults will emerge from numerous places surrounding your property. 

When is the best time to sow grass seed? 

Late summer (mid-August to mid-September) is the best time to establish a lawn from seed in Iowa.  Late summer seeding has several advantages over spring seeding.  The seeds of cool-season grasses germinate quickly in the warm soil of late summer.  Once the seeds germinate, the warm days and cool nights of early fall promote rapid turfgrass growth.  The growing grass also has less competition from weeds as few weed seeds germinate in fall. 

When should I harvest gourds? 

Harvest gourds when the stem attached to the fruit begins to dry and turn brown.  Since the rind or skin is susceptible to bruising or scratching, handle the gourds carefully.  Cut the gourds from the vines with a hand shears, leaving a few inches of the stem attached to the fruit.  After harvesting, gently wash the gourds in warm, soapy water to remove any dirt.  Then wipe the gourds with a soft cloth dampened in a household disinfectant.  The disinfectant should destroy decay organisms which could lead to fruit rot.  Finally, dry each gourd with a soft cloth. 

Dry or cure the gourds by placing them in a warm, dry, well-ventilated location, such as a garage or shed. Place the gourds in a single layer on clean newspapers or shelves.  Space them so they don’t touch one another. Turn the gourds frequently and promptly remove any which show signs of decay. Large gourds can also be dried by hanging them from beams or rafters. Drying or curing will take several weeks. Approximately one to two weeks will be required for the outer skin to dry and harden.  Internal drying will take several additional weeks. The gourds have been adequately dried when the seeds rattle inside. 

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Contacts :

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

Del Marks, Extension Communications and External Relations, (515) 294-9807, delmarks@iastate.edu