Gardening in Almonte: What is a weed?

David

My dictionary defines a weed as “a plant considered undesirable, unattractive, or troublesome, especially one growing where it is not wanted, as in a garden”. The following photo shows my bed of sweet potato vines being overrun by tomato seedlings (which have self-seeded from the tomatoes that were in the bed last year) and by oat seedlings which have sprung up from the straw mulch used in the pathways. Both of these plants would be welcome in the right place but I’m sorry they have no place in my sweet potato bed. Luckily they are shallow rooted and are easy to pull. But are they weeds?

The following photo is of a flower that I have been asked to identify several times this summer. This is the Creeping Bellflower (Campanula rapunculoides) – it is very attractive this time of year and in fact was introduced from Europe as a garden flower. It is commonly seen around town in gardens and in areas that may once have been a tended garden. Is it a flower or a weed?

The Ontario Ministry of Agriculture, Food and Rural Affairs notes that Creeping Bellflower occurs throughout Ontario in lawns, gardens, fence lines, roadsides, waste places and occasionally in cultivated fields. The Ministry adds that it is often planted in ornamental gardens but spreads into adjacent areas by means of underground rhizomes as well as by seed.

Lest there be any doubt, the Ministry terms Creeping Bellflower a very persistent weed primarily because of the extremely persistent, widely spreading, fleshy, whitish underground rhizomes and thickened storage tubers. It is of concern from an agricultural perspective as it is shade tolerant and is able to survive in crops.

In my experience I have found it very difficult to eliminate from places I don’t want it. Any piece of that white creeping root (rhizome) or the tubers left in the soil will send up a new plant. So the roots need to be dug up carefully and it is probably best not to add those roots or tubers to the compost bin.

Noted garden writer Larry Hodgson ranks this plant very high on his list of invasive plants to avoid, right up there with goutweed and Japanese knotweed. You have been warned!!