I do not recommend using any poisons near bird feeders. Robins, cardinals and other ground feeding birds are particularly vulnerable to poisoning. According to the (USGS) National Wildlife Health Center, many birds die each year from landscape weed killers and pesticides.
How to get rid of weeds under the feeder without using poisons:
Rake up the area and cover with mulch or stones
2. Use vinegar as a natural weed killer
Spray the weeds' leaves with household vinegar. Plants sprayed with vinegar will begin to die a couple days after the application, when the sun hits the leaves. Reapply as needed.
3. Plant a ground cover plant
I have lots of good groundcover plants that choke any weed from seeing the light.
How to prevent weeds from growing under the bird feeder:
1. Read the ingredients on the bird seed bag
The number one reason you will have weeds on the ground is because the birds are kicking the seeds that they don’t prefer on the ground and they grow. For seed eating birds in Michigan studies indicate that Black-Oil Sunflower, Fine and Medium Sunflower Chips, Peanuts, White Proso Millet, Safflower, and Nyjer® Thistle are among the most preferred seed types. Each of our blends is regionally formulated to attract the birds that live in our area. We do not include cheap filler grains like oats, wheat and milo that decrease the price per pound of a mix but aren't eaten by the birds in Michigan. Therefore, there is no wasted seed.
2. Discover the No-Mess seed blend benefits
At the East Lansing Wild Birds Unlimited store, customers’ and birds’ preference by far is WBU No-Mess Blend. Our unique No-Mess Blend features seeds that have had their shells removed so only the meat of the seed is left. Pound for pound, our No-Mess Blend offers the best value because you do not pay for the shells. No shells on the seeds means no shells on the ground and the seed won’t sprout either.
3. Feed good suet
Not all suets are created equal. The first ingredient should always be rendered beef suet. Some people feed straight suet only. If you want to offer more protein the next ingredient should usually be peanuts or tree nuts. Never, never buy suet where milo, oats, wheat, processed grain by-products or artificial flavorings are in the ingredients. These filler ingredients are used to make a cheaper cake but the birds have to pick around and pick out all this filler to reach the suet.
4. Tidy, long lasting food
Seed Cylinders are also a high-fat, quick-energy food source that is specially-designed to meet your birds' hearty appetites. The Wild Birds Unlimited popular no muss, no fuss Spiral Seed Cylinder Feeder holds cylinders of tightly packed seed held together with gelatin so there is no seed spray. The whole block is completely edible. And depending on bird activity in your yard, a cylinder packed with energy rich pecans, peanuts and sunflower seeds can last weeks.
5. Nyjer® (Thistle) does not grow Canada Thistle
Nyjer, niger, and thistle are all common names used to identify a tiny black birdseed cultivated in Asia and Africa that is high in calories and oil content, and loved by American Goldfinches. It's sometimes confused with the purple, prickly, Canada thistle but Nyjer isn't related to that weed at all. The scientific name for the Nyjer plant is Guizotia abyssinica. Its bloom has yellow, daisy-like flowers, and before it is shipped into the country the Nyjer seed has been heat treated to prevent the growth of any noxious seeds.