I am an architect, working with a client who wants to hydroseed a 2.5 acre parcel for use as a softball field. The area is currently planted in alfalfa. There will be some regrading (both cut and fill) of the field that will be required. The client would still like to hydroseed this year, likely near the end of September. Do we need to call for the alfalfa to be treated with a herbicide? If so, what is the process, and what herbicide should be used? Is there a waiting period between application of the herbicide and the hydroseeding? Must the herbicide be applied to the above-grade plants, or can the site first be cleared, then the herbicide applied to the gound and roots?



In my view the field could be plowed or the alfalfa could be killed with Roundup (or Roundup plus 2,4-D).  Roundup and 2,4-D are considered foliar herbicides and would need to be applied before the plants are disturbed.  If Roundup is used, we need to wait a week before tilling the soil to give the Roundup time to translocate through the roots.  If Roundup and 2,4-D are used you will get a better kill, but would need to wait a week before tillage and three weeks before planting as the 2,4-D has some soil residual. In Weber County I prefer to have the new grass seeded by the middle of September, but have been successful at the first of October.  Hope for a long fall.

Plowing would be the simple solution and does a pretty good job of killing alfalfa.  In either case you will need to fight some alfalfa roots to get a smooth seed bed.

Posted on 17 Aug 2007

James Barnhill
Agriculture Agent, Weber county

Other Questions In This Topic