You're probably preparing to "clean" your garden for winter. I'd like to make a plea that you not be too tidy. Leave many of your plants just as they are. Don't cut or trim or cart away. And be sure to chop your leaves and put them on your gardens. There are several reasons for leaving your garden a bit "messy" as winter approaches.
First of all, those clumsy wisps of cleome and cosmos will feed the goldfinches and just plain brown finches as winter approaches. And the grasses and stands of coneflowers are a treasure trove for birds and small mammals well into winter.
Secondly, you may inadvertently be disposing of the pupal stage of some of our prettiest butterflies. The black swallowtail in particular overwinters in pupal stage on the stalks of many of your garden flowers and waits until spring to emerge. Wouldn't it be a shame if they ended up in your yard waste collection instead of in your yard?
Third, sturdy stalks and bushy plants catch and hold snow and keep the crown of many of your perennials safe from the perils of the deadly freeze/thaw cycle in spring. It was planned that way.
Fourth, standing plants can add lots of winter interest to your garden. Ornamental grasses are especially nice when snow covers the ground.
And lastly, the life within your soil will benefit from the additional organic matter that you leave as a gift on top of your soil. Soil critters are important to the health and growth of your plants. Start working on next season's garden by providing food for soil critters this fall.
Your garden doesn't need to be squeaky clean. Emulate Mother Nature this fall.