AboutMick Bridge Expertise Expert in agrochemicals. Detailed knowledge of activity, use of insecticides, herbicides, fungicides etc. Benefits, disadvantages of agrochemicals v. organic farming.
Also expert in garden and greenhouse ornamental plants including pest control.
Experience Agrochemicals 30 years in the industry in England, the last 10 years as a self-employed consultant.
Garden plants 30 years as a hobby.
Education/Credentials Degree in Biochemistry from Cambridge University, England
Question QUESTION: how can i get rid of the random alfafa plants growing in my lawn and flower beds and garden?
ANSWER: This is two separate problems; plants in your lawn and plants elsewhere. Firstly, the easier one, the plants growing in your lawn. Unless this is a really big problem, regular mowing will keep them under control and eventually they will die off. For a quicker effect, lawn weedkiller will get rid of them. I would doubt that any brands specify alfalfa control on the label, but otherwise choose one that says it is good for control of clover. There are so many mixtures and brands available that there isn't just one I would recommend.
The plants elsewhere are a little more tricky. In lawns you use a weedkiller that kills the weeds but doesn't kill grass. Unfortunately there aren't any weedkillers for killing one flower (alfalfa) amongst other flowers (the ones you planted). So the best way to get rid of alfalfa in beds is to pull it out or hoe it regularly. Initially it will keep coming back from seeds in the soil, but eventually you will gain the upper hand if you kill each plant before it seeds. If you have areas where there are a lot of weeds and no desirable plants you can spray the alfalfa with a herbicide containing glyphosate. The problem is that glyphosate kills all plants, so the spray must not land on grass or any plant you want or you will kill or damage it.
Before using any herbicide make sure you read the instructions carefully and then follow them.
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QUESTION: if i have an area with a lot of alfalfa, can i use the glyphosate on all of it and still be able to plant things in it next year?
Answer Sorry for the delay in replying. Yes, glyphosate is inactivated on contact with soil. It does not affect seeds only green plant matter. You can, in theory, spray glyphosate and sow seeds the next day, although it is much better to wait until weeds are dead and remove them (up to 2 to 3 weeks after application).
Unfortunately, because glyphosate does not kill seeds, you can only kill existing weeds and any seeds in the soil can then germinate to bring the problem back.
