Tansy or common ragwort, Senecio jacobaea, is a weed of the sunflower family Asteracaeae. It is usually considered to be a biennial, overwintering either as seeds or as rosettes, but it is also capable of becoming a perennial through environmental stress or interference by competitors, herbivores, or control tactics
The plant is erect and robust, ranging from about 1.3 to 6 ft tall, and develops a stout taproot from which grow numerous fleshy roots extending to about 1 ft deep. Leaves are light to dark green and deeply lobed. The lower leaves form a rosette which die back when flowering is well advanced. The upper part of the stem is highly branched and bears up to 250 bright yellow daisy-like flowers. Single plants are capable of producing over 150,000 seeds, which can remain viable in the soil for three years or longer. I have this plant in my fields. We have hand pulled them up, applied weed killer and mowed them over. One of my jobs this year is to try to get a handle on them. I have been fighting the battle, but my field still have many of the flowers in them. It is a battle that starts early in the year and continue until all are pulled, mowed or sprayed. At the end of the year my fields always look good, but come spring. I will have new plants sprouting among the grass and other weeds. This year I have noticed Buttercup weeds.
Creeping buttercup occurs on a wide range of soils but forms large colonies on wet, heavy land. On ridge and furrows, it often occurs in a band along the bottom of the furrows. It can withstand trampling and compaction and is common in gateways and on paths. It can tolerate both waterlogging and a moderate drought.
There are several different kinds of buttercup weeds, including tall buttercup, creeping buttercup, and Bermuda buttercup. All of them have several things in common besides being a problem. They steal nutrients, water, and sunlight from desirable plants and grasses, grow where they're unwanted, and look unsightly. There are several things you can do to remove these aggressive weeds, before they wreak havoc on your garden or lawn.
The cure is almost the same as with the Tansy. Dig them up, cover them with plastic, or use a weed killer on them. We have found that this weed is harder to remove then the Tansy. So with the fine weather that we are now having here in the Northwest, I will be gleefully sprays this weeds. They will take over before you know it. Your once grassy fields will start with one or two plants..blink and you will have a field of pretty yellow flowers, non of which your animal's will want to eat, that will rob the soil of nutrients and smother all of your grass.