Hello, Mary Lou!

This is not Poison Hemlock.  This is Queen Anne's Lace other wise known as Wild Carrot.  

Re:  Wild Carrot or Queen Anne's Lace

The plant forms a basal (low growing) rosette of foliage during the first growing season, and then produces a tall stalk for flower production the second year. The rosettes remain green through the winter. The leaves consist of three lobes that are deeply cut, which makes them look feathery or fern-like. Hollow stems are produced during the second year. They can reach a height of four feet. (Poison hemlock looks similar, but it has purple blotches on the stems and lacks hairs.)

Wild carrot has a distinct yellowish white tap root that can help with identification. White flowers are produced during the second year, typically from June through September. The flowers are small and clustered together in a flat umbel. Wild carrot reproduces from seeds, and an individual plant can produce thousands.

Wild carrot is not a weed issue in mowed turf areas. It is possible for it to grow in landscape beds, where it may require control. Some people do not consider it to be a weed though. Hand removal is also an option in ornamental beds, particularly during the first growing season. Pre-emergent herbicide options are limited to dichloben (Casoron), which is not labeled for landscape use. Post-emergent herbicide applications include clopyralid (Lontrel), diquat dibromide (Reward) and glyphosate (Roundup). Care must be taken with the last two because they are non-selective. Remember to always read the label for specific application sites, precautions and mix rates.

https://extension.psu.edu/wild-carrot-or-queen-annes-lace

Please let me know if you have any further questions or concerns.

Happy Gardening!