Take stem tip cuttings now of geraniums, coleus, begonia, and wandering jew to save space in the house when overwintering plants. For more information, see MU Extension Guide G6560 Home Propagation of Houseplants https://extension2.missouri.edu/g6560.
Fall needle shed of pines is normal at this time.
Consider setting up high and low tunnels to extend the growing season.
Sow cool season cover crops such as cereal rye, winter wheat, tillage radish, and clover in areas of the garden not being used.
Start gathering mulching materials for lasagna garden beds (compost layering). Materials include leaves, grass clippings, peat moss, newspaper, cardboard, and vegetable scraps.
Remove any diseased or insect-infested plant debris from the garden to prevent the pests and pathogens from over-wintering. This will help to limit populations next year.
Keep harvesting ripened tomatoes and "top off" plants to encourage additional ripening as the first frost grows near.
Harvest winter squash and pumpkins when their rinds cannot be easily penetrated with your thumb nail. Cut the fruits with 2 to 3 inches of stem for better storage.
Scout for pests in the garden.
Continue to adequately water vegetables during dry conditions.
Time to harvest apples and pears to enjoy.
Practice good sanitation. Pick up and bury or discard any spoiled fallen fruits on the ground to prevent the spread of diseases spores.
Black walnuts will be falling soon. Hull and cure them or collect and take to your local buyer.
Continue to adequately water fruit plantings during dry conditions.
Scout for fruit tree pests and treat accordingly.
Tall fescue and/or Kentucky bluegrass
September is the most important time to get to work on your lawn and rebuild turfgrass density after a long, difficult summer.
This is the most important time to fertilize cool-season lawns. Apply fertilizer at a rate of 1 lb nitrogen (N)/1000 sq ft. Potassium (K) may also be a component of the fertilizer at a 1/3 to 1/2 rate of the nitrogen, particularly if the soil test indicates a deficiency. Do not apply phosphorous (P) unless a soil test indicates it is needed since some soils are already at high or potentially toxic levels and established turfgrass is good at getting to even lower concentrations. For more information, see https://ipm.missouri.edu/MEG/2019/4/fertilize/.
Mid-September is also a great time to seed or overseed a lawn. If a lawn is less than 50% desirable turfgrass then consider a complete renovation, but in most cases a good overseeding will help rebuild density. Aerate or verticut if possible, then fertilize, (aerate or verticut again if possible), seed and lightly rake in. If the soil is low in phosphorous, addition of this nutrient may be necessary when seeding. Overseeding rates for tall fescue and a tall fescue/KBG mixture is 4-6 lbs of pure live seed/1000 sq ft and a complete renovation is 6-8 lbs of pure live seed/1000 sq ft. After seeding, water frequently and lightly enough to keep the soil dark, but not so much that it glistens (2-3 times a day). See https://extension2.missouri.edu/g6700.
Last but most importantly, you must know the size of your lawn to accurately apply fertilizer or seed. Suggest using the lawn fertilizer calculator here - http://agebb.missouri.edu/fertcalc/. If you don't know the lawn size, or want to check, this web application will direct you to Google maps so the size can be estimated with satellite imagery. As a final tip, if you simply replace nitrogen with seeding rate and germination rate (normally 85-90%), you can also get the amount of seed needed to properly apply to the lawn.
After using the spreader, blow the seeds and fertilizer back off the curb, road, sidewalk, driveway (or any impervious surface) back into your lawn. Don't pollute!
Zoysia should start shutting down, and mowing will be less frequent.
If you did not fertilize during the summer, or fertilize enough, (~ 1 lb N/1000 sq ft) be aware that low nitrogen can result in increased winterkill during tough winters. A light rate of a fertilizer (0.25-0.5 lb N/1000 sq ft) with both nitrogen and potassium may aid in winterkill avoidance.
Ready houseplants placed outdoors for the summer by pruning back excessive growth.
Check houseplants for insects pests and diseases and treat if necessary.
Bring houseplants indoors before nighttime temperatures regularly drop below 50 to 60 degrees F to avoid chill injury.
Place houseplants where they will avoid drafts.
Set poinsettias in a dark closet every evening at sunset and remove in the morning at sunrise to trigger flowering response. The practice can be stopped when coloring on bracts is well underway.