Remove plumes on ornamental grass. And do it soon. While their plumes are part of the attraction, ornamental grasses can be invasive, even those identified as sterile. You can see Miscanthus sinensis invading south-facing slopes along the Pennsylvania Turnpike between Valley Forge and Downingtown. I was once delighted that our 'Moudry' fountain grass ( Pennisetum alopecuroides 'Moudry') came "true" from seed. Little did I know this grass would take off. Its wiry roots are difficult to dig up, and the dense clumps are hard to mow down even with a riding mower. Consider yourself warned.
Make some hard choices. Maybe you went a little crazy with your container gardening this summer. It's time to choose which plants to bring indoors. You may have acquired new "darlings" that you just can't give up. If space is limited, decide which plants you can live without or at least which will be easier to replace next year. If a plant is thriving but doesn't make the cut, it could make a great gift. Plan to move the containers indoors by the end of September. This gives tender plants a chance to adjust to the indoors before the heat goes on.