Most effective treatment of yellow nutsedge?
Question:A damp, warm spring here has led to an invasion of my garden beds and lawn by yellow nutsedge. I've used roundup (doesn't affect it) and weed-b-gone (which sickens it), but it puts on new growth which doesn't seem to be affected by the chemicals that were sprayed a day or two earlier.
I know that you can dig up nutsedge and if you get the nut and all of the rhizomes, it will be gone. My infestation has gotten far past that and I need some knowlegeable advice.
The stuff is starting to drive me crazy. Anyone got any good tips to get rid of this stuff?
PS- Not afraid of chemicals..
Answers:
Yellow nutsedge is very difficult to control once established. With this weed you need to have a zero tolerance and control when young. As you have indicated, control via digging is difficult because of very aggressive rhizomes.
Metolachlor (Pennant) is an effective preemergence control for Nutsedge. Bentazon (BASF Basagran T/O, Lescogran, & Prompt) are selective postemergence control of yellow nutsedge. Image is a postemergence for the control of Purple nutsedge. Halosulfuron (Manage) is a postemergence control for both Yellow & Purple nutsedge. Plan on at least two (split) applications if attempting to control established plants with the above postemergence products. Roundup can work, but it will require several applications and works best when plants are young and not yet flowering. 2,4-D, with multiple applications, can control nutsedge in turf if applied at the appropriate time.
Most systemics work best in late summer or early fall when weeds are actively growing and directing the storage of manufactured sugars to roots, rhizomes, corms, bulbs, tubers, nutlets, etc. Unfortunately, nutsedge is next to impossible to control with a postemergence systemic once their tubers form in July/August. Also, do not try to control nutsedge with a systemic postemergence in early spring because the plant's focus is on suppling nutirents to top growth and you have insufficient leaf surface to deliver a knockout blow. Typical postemergence applications should be made 6-8 weeks after emergence, but before tubers develop. Tubers develop quickly in July & August in Illinois and, therefore, June would be the best time for postemergence applications. Here is good link that discusses the application of Basagran, Image and Halosulfuron for the control of nutsedge in ornamental beds: http://pubs.caes.uga.edu/caespubs/pubcd/...
Pulling the tops off established nutsedges when there are 5 to 6 leaves and doing this repeatedly will eventually deplete the established nutsedge tubers of their energy to reproduce new plants. So, your best control procedure would be the use of a preemergence to prevent Nutsedge. If you miss this opportunity, apply split postemergence applications in June and repeatedly pull the tops off any established nutsedge that survives your postemergence applications.
Good luck!
P.S. Congrats on making the top 10!
I feel your pain with the nutsedge. I had a fairly large garden that had this grass in it and I tried everything, round up, weed be gone and even had a licensed applicator treat the area with a broad leaf weed killer called 24D. No chemical worked. I finally took advice from my grandfather, fenced the area and put two pigs in there. Within a few months they had rooted the entire area and the nutsedge was gone. This is the only way I could get rid of this varmit grass, not sure if it suitable for your garden/area. Hope this helps.
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