I am starting this late, and I am in search for joe-pye weed, goldenrod, and really any other flower that can still blossom this year and help the bees. I have a big garden. I’ve tried to find seeds for the past hour or so and have been unable to locate any. Could you please advice?
Thank-you for contacting Toronto Master Gardeners with your question. Creating a pollinator-friendly garden is a great idea and both Joe Pye weed and goldenrod are good perennials to include in your garden. Unfortunately, you are correct in thinking that August is late to make a start if you are hoping for flowers this season. Annuals need to be planted early in the growing season. Perennial seeds can be started indoors in the winter or planted in the garden next spring. In some cases, when starting perennials from seed, you will not get flowers in the first year of growth.
The only way you will get flowers for your bee garden this year is to purchase plants already in flower or about to flower. Both perennials you mention, Joe Pye weed (Eupatorium) and Goldenrod (Solidago) should be available in nurseries and in bloom. Some other late summer/early fall blooming pollinator-friendly perennials you might like to try are: coneflower (Echinacea), Phlox, Russian sage (Perovskia), and the various milkweeds (Asclepias).
Here is a link to a previous Toronto Master Gardener response to a question about establishing a pollinator garden. It contains good information about planning and preparing your site.
The following is another response regarding starting perennials from seed: