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


Should I fertilize newly planted trees and shrubs? 

It generally is not necessary to fertilize newly planted trees and shrubs. Most Iowa soils can supply sufficient amounts of nutrients during establishment. If the trees and shrubs are growing poorly two to three years after planting, fertilization may be beneficial. Woody plants that are growing poorly often exhibit sparse foliage, yellow-green leaves or short annual twig growth. 


How would you construct a trellis for red raspberries? 

There are several different trellis systems. A two-wire permanent trellis is commonly used to support raspberries in the home garden. Its construction requires wooden posts, No.12 or 14 galvanized wire and 2- by 4-inch lumber. The wooden posts should be 3 to 5 inches in diameter and 6 to 8 feet long. Posts should be set 2 to 3 feet into the ground and spaced 15 to 20 feet apart. Near the top of each post, nail or bolt a 24- to 30-inch-long crosspiece. Then run or attach the galvanized wire through the ends of each crosspiece and down the entire length of the row. The two wires should be spaced about 18 to 24 inches apart and positioned 3 to 4 feet above the ground. 


A temporary trellis may be constructed of posts and twine. Set the posts approximately 15 feet part. The canes are supported by twine between the posts. This temporary structure is most suitable for fall-bearing red raspberries grown exclusively for the fall crop. 


Is it necessary to remove the clippings when mowing the lawn? 

When the lawn is mowed properly, there is no need to remove the grass clippings. The general rule when mowing the lawn is to remove no more than a third of the total leaf area at any one time.  For example, if you are mowing the lawn at a 3-inch height, the grass should be cut when it is 4.5 inches tall.


The small grass clippings will filter into the turf and decompose rapidly, releasing valuable nutrients. The grass clippings may need to be removed if the grass is allowed to grow too tall. The large amount of clipping material may accumulate in piles. These piles of clippings are rather unsightly, tend to smother the turfgrass areas beneath them and create an environment that favors disease development. 



Contacts :

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

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