On Friday, the Yale Farm taught a group of students and New Haven residents to make a salad out of weeds found on New Haven streets.

Justin Freiberg, director of the West Campus Farm, lead a group of about 15 students around the Yale Farm, pointing out various authentic New Haven weeds growing among the plots of vegetables. The group then made its way through the streets of New Haven, where they were told which weeds are safe to eat. Organizers of the event said the act of eating plants not traditionally cultivated on a farm — called foraging — is important both for safety and expanding one’s food options.

“It’s really important that people understand foraging,” said Kate O’Shaughnessy, Lazarus Fellow of food and agriculture at the Yale Farm. “So something like this is a great introduction.”

Each person on the tour was allowed to taste the plants Freiberg introduced, which included dandelions, magnolia flowers, and Japanese knotweed. However, while all the plants introduced were edible, Freiberg warned that there may be pesticides or other substances on the plants in an urban setting, so foragers should be wary of what they pick.

Participants were shown defining characteristics of each plant and learned different uses for the often-ignored weeds, ranging from medicinal to dietary. For example, dandelions can be used as a valuable nutritional supplement, roasted and ground as a coffee substitute, fermented as wine, added to a spring salad or battered and deep-fried, according to Freiberg.

“I had no idea that so many nutritious, diverse things grow around here,” said McLane Ritzel ’14, a student who participated on the tour.

Ritzel took a bunch of white pine needles with her after the tour that the group had foraged, saying that she planned to use them to make tea in the dining halls.

After the tour was over, a meal was prepared with the plants highlighted on the tour. On the menu were dishes such as pesto pasta made with ramp, a type of weed, dandelion and wild mustard salad with chive vinegar and sheep sorrel lemon sherbet with Japanese knotweed compote.

Freiberg explained that many plants that have useful purposes are classified as “weeds” simply because they cannot be easily marketed in a traditional supermarket context — either because they wilt quickly or because they are hard to cultivate on a mass scale. However, many edible weeds are herbs imported from Europe. Mugwort, a weed that covers many vacant lots in New Haven, can be eaten and steeped into tea, as well as used to flavor rice, Freiberg said. Additionally, Mugwort is used by indigenous cultures in teas to stimulate vivid dreams.

Abraham Siegel, who attended the tour because he is helping set up a small farm and gardens at Trinity College in Hartford, was impressed with the nutritional qualities of the plants.

“I think that food can help you much more than medicine in so many situations,” Seigel said, who is a supporter of plant-based diets.

Freiberg said plants are on a spectrum — there are plants that are not completely toxic but still do contain some toxins. It is important to know how much of these you can eat and where it is safe to eat them, and even Freiberg said he is still learning about how to become better at foraging.

On Thursday, Freiberg will lead a tour on West Campus on how to forage mushrooms.