Over the past few years I have noticed an abundance of yellow ...

Over the past few years I have noticed an abundance of yellow flowers along roadways and in old fields. They appear in early summer and look like a yellow version of Queen Anne’s lace. Someone told me they are toxic – is this true? The plant you are referring to is called wild parsnip. Over the past 10 years populations of this perennial plant have exploded. Plants can grow to six feet in height and the yellow flowers that develop in summer are quite attractive. But do not touch this plant! You are correct – it is poisonous! Contact with the plant sap can cause severe burns and rashes. In allergic people this rash is much more severe than a typical poison ivy rash. If you have a few plants on your property, they can be easily controlled by cutting. After that, keep the area mowed to prevent new plants from developing. For larger populations or for plants that are in areas that cannot be easily cut, herbicidal controls are the best option. Do not mow or use a weed trimmer on large populations! This will cause the plant sap to come in contact with your skin more readily. If you have to go near the plants, cover yourself completely and wear gloves if you must handle the plants. Applications of herbicides should be done before the plants flower. If you wait until flowering has begun the plants may produce a seed crop that will lead to more plants next season. Seeds that develop can remain viable for up to four years. For specific information on control, contact your local Cooperative Extension office. By Sue Gwise, Consumer Horticulture Educator, Cornell Cooperative Extension of Jefferson County June 17, 2017