Talking Plants

Jillian Patrie | University of Minnesota Yard and Garden Extension

Mums, pumpkins and straw bales are showing up in stores all over the FM area and it is time to change out summer annuals with fall color.  The fall container and decorating season can be short but here are a few tips for maximizing fall outdoor decor.
The mums you see in the store at this time of year are likely annual mums, however perennial mums are available this time of year too.  Make sure to refer to the label for information on hardiness zones, the FM area is in hardiness zone 4a.  Perennial mums are a great addition to a landscape for late summer and fall color, many of them will begin blooming in late July, lasting through the first hard freeze.  Annual mums come in a bouquet of color options and will start to bloom when the day length shortens.  In some micro-climate cases annual mums will overwinter and last for multiple years.  In these situations, the annual mums were planting near foundations and in sheltered areas.  Cooler night-time temperatures will speed up bloom time and annual mums generally keep blooming through light frost events (32-28 degrees F).
Pansies, millet, viola, ornamental pepper and cabbage, flowering kale and marigolds are commonly used for fall containers.  These can all tolerate a light frost, and last until the first hard freeze.  If you want to prolong containers, cover them with a sheet or pull them inside for the night to prevent frost from settling on flowers and leaves.
Pumpkins and straw bales are another fall decor staple and can last through Thanksgiving.  Prolong pumpkin & gourd lifespan by bringing them inside before any hard freeze (below 28 degrees F) or snow events.  Once they get frostbite, they start to decline quickly.  Carving pumpkins, save the seeds and roast or bake them for a healthy snack while making Jack-o-lanterns.
Straw bales can be used as garden mulch or for straw bale gardening when the fall season is over.  If you are using them for straw bale gardening, look for bales made from alfalfa, wheat, oats, rye or other cereals.  Don’t worry about the bales through the winter, you can use bales in any condition if they are still held tightly together with twine.  More information on straw bale gardening can be found at extension.umn.edu.
Another fall time favorite is changing leaves, shortened daylight hours give plants the que it will soon be time to go dormant.  Chlorophyll gives leaves their green color, and as the day length shortens chlorophyll is no longer supplied to leaves, as the green fades away other colors become visible.  Cooler temperatures cause sugars in the leaf to become more concentrated, giving us those vivid colors we all love.  If you want to see all the fall colors Minnesota has to offer, track the color map here https://www.dnr.state.mn.us/fall_colors/index.html.

For questions about this article or for local assistance please contact Clay County Extension Horticulture Educator Jill Patrie at 218-299-7338 or by email at patri350@umn.edu.