For cool season grasses such as fescue, September is the best month to core aerate, seed and fertilize. Be sure to read herbicide labels carefully regarding the exact timing between seeding and applying weed control products.
Bring summer vacationing houseplants back indoors while the windows are still open. Spray Bonide Insecticidal Soap before bringing your plants inside and/or use Bonide Systemic Houseplant Insect Control.
Dig and store tender bulbs like: dahlias, caladiums, cannas and tuberous begonias.
Start planting spring flowering bulbs.
Pick herbs for drying or freezing.
Allow perennial plants to finish the summer growth cycle in a normal manner. Never encourage growth with heavy applications of fertilizer or excessive pruning at this time. 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.
Fall is a good time for improving your garden soil. Add manure, Coast of Maine Lobster Compost and leaves to increase the organic matter content.
Net ponds before leaf fall gets underway.
Winter Pansies, Ornamental Kale and Cabbage and fall blooming Chrysanthemums can be planted now to give a little color to the garden when summer flowers have faded away. For a bloom explosion, feed with Dynamite, a 9 month fertilizer , after planting.