It’s official, fall is finally here and cooler temperatures are ahead! As your summer annuals are beginning to look tired or may have stopped blooming altogether, now is the perfect time to revamp your flower containers.
Chrysanthemums, or more commonly just called mums, are probably the most common plant we think of this time of year. There are two main types of mums, those sold inside of a florist or grocery that are not cold-tolerant (not hardy) and those that are sold seasonally outdoors which are cold-tolerant to our area (hardy mums). You will want to choose the ‘hardy’ type so that they can withstand the lower temperatures and can even handle a light frost. Choose plants with tight, unopened buds for longevity of the blooms. If we have another mild winter, you can plant your mums in the ground at the end of fall and there’s a slight chance it will come back again next year if they are the hardy type. Mums come in a wide range of colors including orange, red, yellow, purple, white and even burgundy so you can choose your favorite and mix them with other seasonal plants to create a festive display.
When creating your fall containers, you can follow the classic “filler, spiller, thriller” method to get both height and fullness to your arrangement.
Save money by reusing annuals from your summer containers such as snapdragons, dusty miller, and marigolds if they are still holding up well. Other fall annuals to add to your containers include fall aster, ornamental cabbage, pansies, violas and even Swiss chard or kale (which are both tasty, too!). You might also find good deals on perennials this time of year which can also be added to your containers to add interest. Yarrow, butterfly bush, coneflower, black-eyed susan, and blanket flowers all have neat seed heads that can be interesting even after their petals are gone. If you want to get really creative, you can work in some succulents or small ornamental grasses to make it more unique. Tie it all together by displaying pumpkins, gourds, and attractive branches from red-twig dogwoods, hawthorns or evergreens.
Once you have gathered your plants and are ready to put the container together, follow these general guidelines to help your containers last until the end of the season:
You can use a number of different container types including plastic, glazed ceramic, terra cotta, wood crates, etc. Each will differ in their watering requirements and all should have at least one drainage hole at the bottom.
Refresh the potting media by loosening it, adding 50% new mix and removing any old plant roots from the container.
Be sure to break up any rootbound plants by gently teasing/pulling the root system apart with your fingers before planting. Even though it’s cooler, the plants will still grow but you can use a bit tighter spacing since the season is short.
Add slow-release fertilizer at planting and water the container thoroughly once all plants are in place.
If you are using perennials and want to overwinter them, you can plant them in the ground by late October and mulch well. Or you can simply bring the containers into an unheated garage or cool, dark space. Remember to water occasionally throughout the winter.
Containers are a fun and easy way to decorate for fall and make the most out of your space for the full growing season! For more information on fall gardening, visit extension.colostate.edu or contact your local CSU Extension Office.
By Amy Poston Lentz. Amy is the Home Horticulture Program Coordinator for Colorado State University Extension Boulder County in Longmont. https://boulder.extension.colostate.edu/