This shrubby, woody weed has taken over my 30 x 50 ft. garden in the last 3 years and this year the chicken yard. The chickens won’t eat it, although they eat everything else. It is 2-4 ft tall, has a woody stem and tiny yellow flowers. The seeds are small, round and black. It has no thorns. It is very hard to pull out of the ground. It is nowhere else on my property. In the past I have put straw mulch in my garden, and have bought plants from a nursery–that must be where it came from. I have not been able to plant my garden for 3 years due to this pest.
your plant is named Sida rhombifolia – the common sida or arrowleaf sida – and it is actually related to both cotton and hibiscus – in the family Malvaceae. In Georgia, as I understand, people call it Ironweed because it is so hard to pull up, but there is a different plant, Vernonia, that is usually called ironweed. This common sida is introduced in our area. It isn’t toxic at all, but the seeds have little spines on top. It is an annual in our area, normally, so it is best to try and get rid of it early before it flowers, and it is easier to pull up then.
Steve Hill, Botanist, SCNPS