The Homeowners Column

The Homeowners Column

September garden "to do" list

Photo of Sandra Mason

Sandra Mason
State Master Gardener Coordinator

September is a month of second chances. A chance to plan and plant, dig and divide; to do all those things we didn't do in our gardens in the spring. If you have the urge to garden, but are not quite sure what to do, this reminder list should help; or you may develop a sudden urge to throw a rotten tomato toward my head. Remember a gardener's "to do" list is never done so enjoy the process.


  • Transplant and divide most perennials.
  • This is the best time to divide peonies. Be sure to have 3-5 eyes, which resemble pink noses, per division. Replant so eyes are no more than 2 inches deep.
  • Replant containers with frost tolerant plants such as mums, pansies and flowering kale. Place old plants in compost pile. No need to replace soil unless diseases were a problem.
  • Plant mums into well-drained garden areas. Plant on a slight mound to provide proper drainage to get mums through the winter.
  • Prepare houseplants for return trip indoors. Scout for insects. Thoroughly rinse leaves and container. Move to a sheltered area.
  • Begin 2-3 month dormancy for amaryllis bulbs. Do not water. Place in cool dark place. Dormancy begins once leaves yellow.
  • Purchase spring flowering bulbs for October planting.
  • Discontinue rose fertilization. Remove diseased leaves.


  • Harvest herbs such as sage and oregano by hanging clean stems upside down in dark space.
  • Pot chives, oregano, basil or rosemary for winter use indoors.
  • Order garlic bulbs for planting in mid-October. Try softneck and hardneck varieties.


  • Mow to 2 inches and water as necessary.
  • Fertilize in early September. This is the most important application of the year.
  • Reseed bare or thin areas with improved cultivars. Consider renting a slit seeder to get seed down into soil of existing lawns.
  • Reduce thatch if more than one half inch by using core aerifiers or vertical mowers.
  • Core aerifiers may be used to reduce soil compaction.
  • Establish turf by seed (best time). Prepare soil properly and get good seed to soil contact. Select turf mixes and blends appropriate to the site and to maintenance practices. Northern Illinois – August 15- September 7; Central Illinois – August 15 – September 15; Southern Illinois – September.


  • Continue harvesting vegetables to keep plants productive.
  • Add compost to garden beds.
  • Pumpkins and winter squash should have hard rind before harvesting.
  • Seed bare areas with winter rye or barley for a winter cover crop.
  • Spinach and other leafy crops can be planted for a fall crop.


  • Plant most trees and shrubs. Be sure not to plant too deep. Trunk flare should be visible after planting.
  • Water trees and shrubs. Plants, especially evergreens, should be well hydrated entering winter.
  • No need to worry about white pine trees that naturally drop many of their interior needles in fall.
  • Avoid severe pruning now if possible. Wait until February or March for most trees and shrubs. Spring bloomers should be pruned immediately after bloom.
  • Pick bagworms from evergreens. Pesticide sprays are not effective at this time. Spray with Bt products such as Dipel or Thuricide next year mid-late June.


  • Prepare soil now for a spring planting of blueberries or rhododendrons. A soil test will indicate how much sulfur to add to lower the pH to 4.8-5.2. Also add plenty of organic matter such as leaf compost.
  • Add plant debris from flower and vegetable areas to compost pile. Debris will decompose faster if it is shredded or chopped. Also layer with soil or compost.
  • Average first frost date in our area is October 14. For your area check

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