Garden variety
Can you tell a weed from a flower?
Weeds don’t always announce their invasion by growing to a height of five metres, causing blisters and making headlines, such as the infamous giant hogweed.
Many weeds look harmless or even pretty, but don’t let the delicate blooms fool you — they can take over a garden bed in no time.
Often, weeds thrive in poor conditions, have strong root systems and produce a huge amount of seeds, making it important to nip them early, says Jane Davey, program co-ordinator for the environmental landscape management program at Seneca College’s King Campus.
But it can be tough to tell the difference especially early in the season when the first green shoots start to appear.
“If they’re very young, it’s difficult to tell what you’re ripping out,” says Carole Ann Lacroix, assistant curator at the University of Guelph’s OAC (Ontario Agriculture College) Herbarium, which is part of the Biodiversity Institute of Ontario.
See if you can tell these flowers from weeds.
Oriental poppy ( Papaver orientale)
Answer: Flower. Don’t pull out these perennials before they bloom. The flowers look like brightly coloured crepe paper, but until they burst in spring, can appear thistlelike.
Celandine poppy or wood poppy ( Stylophorum diphyllum)
Answer: Flower. The perennial bears yellow flowers and is native to eastern North America. Its umbel and flat leaves can appear weedlike. Can also spread and cause skin irritation.
Jimsonweed ( Datura stramonium)
Answer: Weed. If consumed, the seeds of this annual herb can cause hallucinations and poisoning. It’s a weed if you don’t want the risk around kids or animals.
Periwinkle ( Vinca minor)
Answer: Both. Periwinkle can be planted as a colourful ground cover but can also be very tough to get rid of. It’s sold in garden centres but can interfere with native species and the pollinators that rely on them, Davey says.
Creeping Charlie ( Glechoma hederacea)
Answer: Weed. This yard crasher has little purple flowers, which can be cute. But the vine roots at each node and can “outcompete” your grass, Lacroix says.
Goutweed ( Aegopodium podagraria)
Answer: Weed. This variegated variety is so tenacious, a small piece of leftover root can start a whole new plant and can take years to fully eradicate. Its green and white leaves can be confused with hostas, and the goutweed’s umbel, or flower cluster, looks similar to Queen Anne’s Lace.
Burdock ( Arctium minus)
Answer: Weed. In this biennial’s first year, burdock’s large leaves and thick stalks resemble rhubarb but they are not edible. In its second year of growth, burdock creates burrs that will stick to your fleece, garden gloves and family pets. Burdock has a long taproot and can be tough to eradicate, Davey said.
Garlic mustard ( Alliaria petiolata)
Answer: Weed. This invasive species was imported from Europe for use as an edible herb, but is now known as “one of Ontario’s most aggressive forest invaders,” according to the province. At Seneca College’s King Campus, the weed is already a foot tall. “We are pulling it out of every garden here,” Davey says.
Creeping bellflower ( Campanula rapunculoides)
Answer: Weed. You must dig out the entire root of this weed, which can choke out other flowers if allowed to spread. The weed blooms in June but spreads by underground rhizomes and by seed, and can become a persistent weed. Bellflower often grows wild near fence lines and roadsides.
Bindweed ( Convolvulus arvensis)
Answer: Weed. This weed grows an extensive root and rhizome system and bears trumpet-shaped flowers that resemble Morning Glories. Bindweed competes for water and nutrients and will grow like a vine, strangling other plants. It roots down wherever it touches the earth.