Garden Checklist: September


Warm Season Grasses  

Bermuda and Zoysia 

Begin to raise the mower deck height slightly to acclimatize the turf before the first frost. Do not apply nitrogen. Lime, sulfur, or potassium can be added based on soil testing results. In late Sept, apply a pre-emergent if desired. Do not apply a pre-emergent if overseeding with rye. Overseeding with ryegrass is optional in the winter months.  

Test your soil for PH. 
Mow frequently enough so that no more than 1/3 of the grass blade is cut. 
Aerate grass in Sept-Nov to loosen compacted soil and promote healthy growth. 

Cool Season Grasses  

Kentucky Bluegrass 

Due to summer stress September is the best time to reseed the grass to help the thin or bare spots. Lightly water every day until the seed has reached 1 inch. Only apply pesticides, herbicides, or chemicals once the seed is established. The grass should not be mowed until it reaches a height of 3 inches or more.  

Mow frequently enough so that no more than 1/3 of the grass blade is cut. 
Aerate grass in August – November to loosen compacted soil to promote healthy growth. 

Tall Fescue 

Lower the mower deck height to cut at a height of 2 ½ – 3 ½ inches. Apply a 16-4-8 fertilizer at the rate recommended on the label in September, and use 1 pound of nitrogen per 1000 square feet. Water lawns in the morning with 1 inch of water per week (unless raining) to prevent disease. Apply herbicide to control dandelions, wild onions, and cudweed.  

Mow frequently enough so that no more than 1/3 of the grass blade is cut. 
Aerate grass in August – November to loosen compacted soil to promote healthy growth. 


  • If growing winter annuals from seed, sow in containers for out planting once the weather cools. 


  • Order spring flowering bulbs for next year’s early flower display. Bulbs usually ship when it’s time to plant them. Plan for different flowering times to extend the season. 
  • Fall is the time to divide and transplant perennial plants that flower in the spring while fall flowering ones like chrysanthemums should be done in the spring. Cut back tops to 4 -6″ to reduce transplant stress.  
  • Some perennial flowers and bulbs will start to go dormant this month. Marking their location with a painted popsicle stick or drawing out a map of your bed is helpful come spring so you don’t forget where things are. 
  • Dig, divide, and move daylilies after they have completed their bloom. 
  • Plant peonies. 

Shrubs and Trees 

  • Check early camellia varieties for damage caused by insects and disease. 
  • Avoid pruning trees and shrubs since doing so this late in the season can stimulate new growth that will not harden off in time for the cold winter weather ahead. Delay pruning until late fall and winter.  
  • Do not fertilize woody plants in late summer. It will stimulate new growth that might not have time to harden off before winter’s first frost. 

Fruits and vegetables 

  • Be sure to keep strawberry beds weed free. Every weed you pull now will help make weeding much easier next spring. 
  • Get any cover crops you want to use in by mid-month. (A cover crop is any crop grown to cover the soil and may be incorporated into the soil later for enrichment.) 
  • Late this month, start to plant next year’s garlic, shallot, and perennial onion crop. 
  • Fertilize established strawberry plantings with a low nitrogen fertilizer. 
  • Continue planting cool season crops of carrots, collards, kale, lettuce, mustard, onion seeds, parsley, radishes, spinach, Swiss chard, and turnips. 


  • Keep inspecting for pests and diseases. 
  • Allow plants to finish the summer growth cycle in a normal manner. Never encourage growth with heavy applications of fertilizer or excessive pruning this late in summer. Plants will delay their dormancy process that has already begun in anticipation of winter in the months ahead. New growth can be injured by an early freeze. 
  • Improve your garden soil by adding manure, compost and leaves to increase the organic matter content. Wood ashes contain phosphorous, potassium, and calcium. They can be placed on vegetable gardens and flower beds as a top dressing that will feed into the soil all winter. 

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