Fall & Winter Gardening Checklist
September:
-Fertilize lawns while grass remains green. Grass cannot absorb nutrients during dormancy.
-Similar to grass, fertilize trees, shrubs, and perennials before dormancy.
-This is the final month to plant trees, shrubs, and perennials. Use a root stimulator to help encourage vigorous root growth.
-Prune spring and summer blooming perennials.
-If temperatures are expected to dip below freezing, buy a row cover and protect any tender perennials.
-Plant cool-weather vegetables early in the month. These are all great choices: click me!
-Put preemergent down to control weed seed. If you’re planning to spread grass seed in fall, we DON’T recommend putting preemergent alongside it, as it will kill your new grass seed too. Normally, we recommend spreading preemergent in fall and seeding in spring.
-Keep on top of weeding to limit their spread for next spring.
-Remove spring and summer annuals as they fade. You can replace them with fall annuals like pansies and mums.
-Consider collecting seeds from plants you want to continue growing.
-Many perennials can be divided now, like irises, hostas, peonies, daylilies, rudbeckia, and coneflowers.
-Non-hardy bulbs like dahlias should be pulled out of the garden and overwintered soon.
-Slow watering of roses to harden them off for winter.
October
-Plant fall bulbs early in the month before the ground freezes.
-Clear out all old vegetables and annual plants. If none appear to be diseased, they may be composted. Discard diseased and insect-infested plants in the trash.
-Once vegetable beds are clear, consider spreading straw or animal manure to fertilize beds over winter. You could also plant cover crops like alfalfa, red clover, vetch, and annual rye. Learn more about cover crops here: click me!
-Blow out sprinklers and insulate outdoor faucets and hose bibs. Here are some winterizing sprinkler techniques: click me!
-Rain barrels should be cleaned, disinfected, and disconnected until next spring. Allowing rain barrels to freeze with water still inside damages the plastic.
-Create brush piles of fallen leaves and twigs as winter shelter for beneficial insects and birds. For fire safety, keep them six feet away from flammable structures and buildings.
-Clean and store bird baths if you don’t plan on using them over winter.
-Consider overwintering fountains, as even the largest ones can crack open if they freeze solid. We do sell fountain covers.
-You can attempt to winterize container plants; however, we strongly suggest planting all perennials, trees, and shrubs in the ground. Container plants are less likely to survive, and even with CSU’s directions, we can’t promise they’ll make it. Here’s a guide for winterizing container plants: click me!
-Add mulch to newly planted roses to protect crowns from extreme weather.
November
-Clean up all pumpkin debris as soon as Halloween is over. Leaving it out can make wild animals sick and transfer two fatal diseases among deer and elk: acidosis and chronic wasting disease. It can be composted if mixed well.
-Now is a great time to sharpen and clean garden tools. Here are a few sources on how to do that: How to winterize garden tools: click me! Winterizing lawnmowers: click here!
-Winter water from now till May on days over 50 degrees Fahrenheit, as needed. Use wilfpruf to retain moisture.
-Spread seed for plants that require cold stratification. If our winter is warm again, they can be kept in the fridge.
-If you haven’t yet, add mulch to newly planted roses to protect crowns from extreme weather. Add rose collars to small, weak, or more sensitive rose varieties. Here’s a great video on how to winterize roses: click here!
-Think about when you want paperwhites and amaryllis to bloom and plant accordingly! Depending on the variety, paperwhites take four to six weeks to bloom, and amaryllis six to eight weeks to bloom.
December:
-Winter water on days over 50 degrees Fahrenheit, as needed. Use Wiltpruf to retain moisture.
-Purchase and use Wiltpruf for cut Christmas trees.
-Plan for next year’s garden!
Sources:
Dash, Jan. “Fall And Winter Garden Checklist – Pueblo County Extension.” Colostate.Edu, 2026, https://pueblo.extension.colostate.edu/fall-and-winter-garden-checklist/. Accessed 7 Sept. 2026.
“Fall Gardening – PlantTalk Colorado.” Colostate.Edu, 2026, https://planttalk.colostate.edu/topics/fall-gardening/. Accessed 7 Sept. 2026.
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