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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.

9/26/2007

What is thatch and when should it be removed? 
Thatch is the layer of dead and living plant material that forms between the soil surface and green vegetation.  It is composed of shoots, crowns and roots. Thatch, to some degree, is present in all lawns. However, when thatch is present in amounts greater than 0.5 inch, it is usually detrimental. Excessive amounts of thatch increase the potential for turf damage due to drought, extremes in temperature, diseases and insects. The potential for damage increases because the turfgrass roots are growing in the thatch layer rather than in the soil. 

Several factors promote thatch development. Heavy nitrogen fertilization, excessive irrigation and infrequent mowing are the main contributors of thatch. The most effective way to remove excessive thatch (greater than 0.5 inch) is with a vertical mower or power rake. Late summer (September) is the best time to dethatch lawns in Iowa. Late summer dethatching gives the turfgrass several weeks of good growing weather in which to recover. Dethatching machines often are available at rental agencies. 

What is the proper way to harvest and store popcorn? 
The moisture content of popcorn determines its popping quality. The ideal moisture content of popcorn is 13 to 14.5 percent. 

Popcorn should be left on the stalk until fully mature. Harvest the ears when the husks are brown and the kernels are hard and shiny. After harvest, remove the husks and place the ears in a mesh bag and hang the popcorn in a warm, dry, well-ventilated location for a few weeks. After drying the popcorn for two to three weeks, remove an ear of popcorn. Shell a portion of the ear and pop the kernels. If the kernels contain too much moisture, the popped corn will be small, rough and “chewy.” Allow the popcorn to dry for another week. Then shell and test pop a few additional kernels. When the kernels pop well, shell the remainder of the popcorn. The chaff can be removed by pouring the kernels from one container to another outdoors, allowing the wind to remove the debris. After the popcorn has been cleaned, store the kernels in airtight containers. 

When should garlic be planted? 
Garlic cloves can be planted in early fall or as soon as the ground can be worked in early spring. Fall planted garlic should be mulched with several inches of straw in late fall. The mulch should be promptly removed in early spring.

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Contacts :

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

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