Hi Kim,

Thank you for your question. Lesser celandine (Ficaria verna) is an aggressive perennial flowering plant in the buttercup family Ranunculaceae. It is invasive and will carpet and take over your lawn. It can be removed by manually, digging out the entire plant, including its tubers and bulblets, to prevent regrowth. But if any portion of the bulblet is left in the ground it will regrow. This may be happening in your yard if you are disturbing the soil and moving other plants.  Disturbing the soil any way may not get all of the plant out and will lead to further plants growing.

Lesser celandine spends most of the year underground, from summer to early winter as thickened tubers that resemble figs (hence its alternative name, fig buttercup). After flowering, the plants die back above ground, and spreads underground via the tubers. So timing of removal is important. Chemical control using systemic herbicides, like glyphosate, is effective, especially during the active growing season in early spring. Glyphosate should be applied when the temperature is above 50 degrees, before the summer when the above ground plant goes dormant. Be aware that glyphosate is non specific and will kill any plant it comes into contact with. Please read and follow all instructions and safety precautions on the label when using herbicides. Also check your counties local herbicide laws.  You may also consider putting  in a  root barrier between your yard and your neighbor's - this should go down about two feet.

Here is a link to maintaining a healthy lawn in Maryland that may also be helpful as you get the Lesser celandine under control. 

I hope this is helpful.

Christine