September ideas

Make a note of those annuals that are blooming during this hot weather. Note the colors and varieties that you like. You may want to plant the same one’s next year. Check the local nurseries for cool season seeds that are available. You can sow them now to have blooms during our cooler days into fall. Be sure to read the germination dates as some need cooler temperatures to germinate. 
If your container plants are receiving essential nutrients no fertilizing should be needed this month. When they have finished blooming you could replace them with new plants when cooler days arrive. Watch for the fall blooming chrysanthemums and others at local nurseries. If you find spring blooming bulbs at the nursery now you can purchase them but don’t plant them in this hot weather. It is best to select individual colors. Mixed colors often clash and won’t be the true color that you expected. Put them in a cool dry place, like the vegetable bins in the bottom of the refrigerator. Wait until October or November to plant them. It is time to divide and transplant irises now. Granular rose fertilizer does well for nourishing bulbs in this area.  A 3:1:2 ratio long-lasting slow-release works fine. Water newly transplanted irises generously.
The houseplants that you took outside for the summer can be conditioned now by placing them in a shady spot if they were in a sunny place for the summer. This will get them used to lower temperatures when you bring them inside. You may need to consider a different place for them in the house if they have grown larger during the summer. They may need to be repotted into a larger pot or divided if necessary. Any pruning should be done before they are brought into the house. Plants grown outside still need watering if weather turns cooler. Make sure it needs it before you water. Watering the lawns continues to be important so maintain the watering schedule.
How much care did your perennial beds require this summer? Were you able to keep up with the weeding? You may want to reduce the perennial beds or try some new varieties next spring. This is the time to relocate the beds and transplant those that you liked. If you have perennials growing in containers you could consider transplanting them into the beds. If you want to keep them in the containers, some may need to be repotted into a larger container if they are root bound.
These ideas should keep your plants healthy and growing with minimal maintenance on your part.