There are many different ways that plant, insect, and disease pests can enter Minnesota. The particular method of introduction for a pest is called a pathway. This month, as folks go to the florist to get Valentine’s Day arrangements, it is an appropriate time to explore the cut-flower industry. This is a potential pathway for noxious weed introduction. Most people would not think of a floral arrangement as being a possible source of a new weed infestation, but this can and does occur.

There are a couple of ways that plants used in floral arrangements could become problematic invaders. First, the arrangement itself could contain propagative material, such as seeds or pods that, upon being thrown out, may germinate and grow. A good example of this can be seen with Oriental bittersweet (Celastrus orbiculatus) vines, which in the past had been grown for ornamental use. It is occasionally still grown today, mistaken for American bittersweet. There are documented cases in Minnesota of Oriental bittersweet infestations that got their start from holiday wreaths containing bittersweet vines and berries.

The second way would be if growers or gardeners start to grow the plants commercially or for personal use. These plants could then easily escape cultivation and invade surrounding natural or agricultural areas. Good examples of this phenomenon in Minnesota are baby’s breath (Gypsophila spp.) and Queen Anne’s lace, Daucus carota. We will take an in-depth look into Gypsophila next month.

If you find a noxious weed in Minnesota, please report it by calling the Arrest the Pest at 888-545-6684 or emailing