We purchased a house last year and a previous owner obviously enjoyed gardening. There are some beautiful plants that have popped up, but I was hoping to please have some help in identifying what I believe are weeds (although I’m not entirely certain).
Thank you for contacting Toronto Master Gardeners.
This is considered a weed but some would call it a wild flower. It is called Erigeron annuus or annual fleabane, from the aster family. It is an annual or a biennial depending on when the seed germinates. This means it can grow and flower in one season or over winter and come up in late spring. It can bloom from June to late fall.
The plant begins with a rosette of green leaves near the ground. At this point it will either shoot up a stem or over winter until the spring. The stem can grow quit tall and has pretty small aster or daisy like flowers. The flowers go to seed and that is how they spread. Once it goes to seed the plant has completed its life cycle.
If you do not want the plant to reseed it is important to remove the plant before the seeds develop. It may take a bit of time for new plants to stop growing as you probably have a bank of the seeds already in the soil. If you keep picking them they will start to disappear from your garden over time. Any time you do any digging you may have a new outbreak from seeds that become exposed with the turning of the soil.
Here is the link from the Ontario Ministry of Agriculture if you would like to read more about it.