Volunteer plants: Weeds or happy coincidences?

Volunteer plants – those that sprout in unexpected places from seed that overwintered in the soil – dotted and in one case completely covered my flower gardens this spring and summer. And I didn't mind one bit. "A weed is a flower growing in the wrong place," said noted agriculturist George Washington Carver. Ralph Waldo Emerson put it this way: "What is a weed? A plant whose virtues have never been discovered." In my case, viola seeds escaped their containers a year ago and gave me unexpected color in the early spring. Those in the shade are still giving me bright yellows and purples. My dill, also in a container, went to seed last summer while we were out of town. I didn't think much of it, until a feathery weed completely covered my front garden this spring. The weed smelled suspiciously like one of my favorite herbs – and it was! It looked terrible from the street, but I had a beautiful crop of dill that I froze, gave away, and tossed into salads. Several asters have appeared here and there, likely spread by the wind. I transplanted a couple of them that were shaded by other plants to sunnier spots. While not spread by seed, greater periwinkle, or vinca major, slipped its container several years ago and slowly has become a bright green and white ground cover in one garden. It is only marginally winter hardy in Ohio, but if we lived near a wooded area, we would need to keep an eye on it. It spreads through rooting runners or stolons and can form a thick mat, choking out important native plants. It has been easy to keep in check in my garden and I appreciate the weed suppression it provides. However, its relative vinca minor is much more aggressive and considered invasive in some states. Last summer our friends down the street discovered a healthy tomato plant growing near their curb, so they did what all fun-loving people would do: they put a cage around it. The plant produced delicious cherry tomatoes. Their "free tomatoes" sign attracted a lot of takers on our street with heavy pedestrian traffic. Another plant is in its place this summer, and the cage is back. We will have to wait and see if its tomatoes are as good as last year's. If the seed came from an heirloom or an open pollinated tomato, then the fruit from the plant will be identical to its parent. Rutgers and Taxi are examples of open pollinated tomatoes and Brandywine, Cherokee Purple, and Green Zebra are examples of heirloom tomatoes. All heirloom plants are open pollinated, but not all open pollinated plants are considered heirloom. However, if the seed in a volunteer tomato came from a hybrid, the fruit could be delicious or terrible. It will mimic one of the grandparents in the cross, which could be for taste or could be for disease resistance or hardiness. For more about this and saving seed, see South Dakota State University Extension information at https://tinyurl.com/mrxjevu5 and University of Maryland Extension at https://tinyurl.com/volunteertomato. For farmers, volunteer plants are a real problem. Volunteer corn, for example, can cause a 10 to 50% loss of soybean yields, by robbing nutrients, introducing pests and messing with crop rotation strategies, according to University of Minnesota Extension. See https://tinyurl.com/volunteercorn. For me, my garden is one big experiment. I'll take volunteer plants when I get them. If they are in an inconvenient spot, I'll move them. If tomatoes from a volunteer plant are terrible, I'll throw them away. And if they are delicious, then we will enjoy another happy coincidence.