The fun thing about seasonal planters and urns is the opportunity to change them out as soon as plants start to decline or stop flowering. After all, the purpose of planters is to install showy new plants as accents whenever you feel like it without having to do a lot of associated gardening work. If your summer annuals are fading, consider replacing them with new plants for fall. There are a number of options, even with Ontario’s cool fall nights and early frosts.
Cool Weather Annuals for Planters
Most annuals are tropical plant species. Southern Ontario can pass for the tropics during summer, but by early fall many annuals have decided they are done for the year and, since they are annuals, they won’t be coming back.
Fortunately, a few species of annuals such as pansies, snapdragons, dianthus, bachelor’s buttons, petunias and calendula (also known as pot marigolds) can all handle cool nights. Pansies will even survive mild frosts. With most of these annuals, if they have been flowering through the summer, you should deadhead the old flowers. That will keep them producing into the fall, though a late summer fertilizer boost may also help.
As freezing weather approaches, you have a couple of options for extending the life of your annuals in planters. Depending on the size of your urns and and planters, bring them inside for the night if it’s going to freeze. For larger planters, place a sheet or garden cover cloth over them in the evening and remove it in the morning. That should be enough to protect your annuals during a mild freeze.
Fall Perennials for Planters
Another option for planting urns in fall is to use perennials. As opposed to annuals, perennials return each spring and start to grow again. Though a hard freeze will stop their growth for the year, most perennials are hardier than annuals and will look better later into the fall. Be aware that some perennials will not survive through the winter in above ground planters, but it is fine to treat them like annuals, replanting each year.
Delphiniums will often produce a second set of flowers in September if you cut them back after their first flowering in mid July. Chrysanthemums and asters have always been dependable fall bloomers. You might also consider a less traditional native plant like goldenrod. Their showy yellow stalks will brighten up your fall planters.
Consider adding ornamental grasses to your urns for fall. Many grasses are at their best in late summer and fall as flowering plants begin to fade. Switchgrass, little bluestem and indiangrass are some native favorites. Though they will turn brown by winter, the foliage stalks stay in place. You can either cut them back or let them stand through the snowfalls of winter.
The best thing about seasonal planters is there are no set rules. If your summer annuals are still flowering, remember to deadhead them and they may continue into fall. If they have faded or you are tired of them, plant some cool weather annuals or a mixture of different plants. Try some fall flowering perennials and ornamental grasses. They will give your planters a new life and a new look, keeping winter away a little while longer. For more fall planting ideas, contact the garden experts at Lawrence Park Complete Garden Care.