For me in my geographic region, one of the most eye-opening lessons I learned is how many butterflies overwinter as caterpillars or chrysalides. So, it's important to me not to do too much fall clean up because it can be hard to see if there is a chrysalis attached to a branch.

I also avoid raking up too much in the garden and just let the leaf matter decompose and/or provide more coverage for the pupae or caterpillars of various moth/butterfly species that may overwinter in or on the ground.

So, be a "lazy" gardener for the benefit of butterflies.

Allow for some weeds--many provide food for butterflies in larval and/or adult states (clover, sheep sorrel, dandelions, cinquefoil; would love to see more posted here).

Another thing I harp about is allowing spots in a yard (if possible) to just "go natural"--the uncultivated spots that I've allowed to return to native flora are often the places with the most life--native grasses provide food for so many different kinds of skippers and other types of butterflies and I have loads of native asters and goldenrods that are key nectar and host plants. Also, all of these grasses provide nice cover for the butterflies at night and/or during the cool nights and cover from predators.

This is a GREAT post. Many butterfly gardeners are not aware of the needs of butterflies beyond nectar and host plants. Many of my suggestions will not be usable for some/many butterfly gardeners because we have a one-acre butterfly sanctuary in a wooded area, but here goes:

provide water source(s)

leave brush piles and wood piles for protection from rain and for overwintering.

leave as many trees around your garden as possible to protect butterflies from strong winds/rain/etc.

provide stones, boulders, gravel in places that get good sun for warming spots for butterflies.

clear spider webs from your garden to prevent butterflies from being caught and release butterflies that are caught in webs.

try for multiple planting levels as various species seek out different levels.

consider planting various grasses suitable to some butterflies as host plants.
leave some trees IN your garden, if possible. In addition to the tree uses mentioned above, some butterflies like emperors, angle wings, wood nymphs, etc. use the bark as hiding places, places to bask in the sun, and lookout spots.

provide feeder plates of rotting fruit, etc. to attract butterflies that don't nectar or don't nectar exclusively.

Another thing we avoid are herbicides and pesticides--even the organic kind.

My backyard is totally wild and thus provides much shelter for the overwintering butterflies like Goatweed Leafwings for instance. I leave the leaves (cool huh?) for hibernating butterflies and especially the sumac leaves for the Red Banded Hairstreak because that is their host, rotting, fallen leaves of sumac.

I quit use chemicals about 5 years ago.

I leave all my plant stalks up over winter. Some are borderline hardy and this helps to better protect the root systems. Also allows seeds to mature and fall for reseeding, e.g., Verbena bonariensis, False Nettle, sennas, zinnias, Mexican sunflowers, cleomes, etc.

Trees such as the hackberries contain hibernaculums for Hackberry and Tawny Emperors that overwinter as caterpillars and emerge in spring to complete their cycle as larvae. So be careful when brushing up against dangling, errant branches, that may be harboring the caterpillars. Don't trim those trees too early in spring without inspecting before trimming.

That's all I can think of for now.

By the time late November rolls around, many of the leaves have fallen to the ground, so it's easy to do some trimming and cutting dead stems away too. Today, I just started pulling up some grass that infiltrated a bed, and I give it a semi-thorough inspection. Sometimes I may just leave the stuff that I pulled up in the area and compost in place; that way, if there happen to be any butterfly larvae/pupae, they have an okay chance of making it.

I may do more thorough clean up in the very late winter--nice thing to do on those warmish winter days.

It's not easy when dealing with all of the overwintering butterflies and moths. There really are many different kinds that stick around here. Amazing really.

If you have any willow in the area, look for hibernaculums, rolled up leaves that remain attached to the tree, that house butterfly larvae like the Red-Spotted Purple, Viceroy, and White Admirals. Look for them as young caterpillars in the early spring when they come out to feed on the new green growth of the willows (salix).

Hope this helps a little.

A good idea during the butterfly season, is to use a fruit plate instead for butterflies that prefer rotten fruit. Some use a nectar recipe, but I just use a hanging suet feeder that I put my black bananas, rotting peaches, oranges, watermelon, etc., in and the butterflies love it. The ones I get are Hackberry Emperors, Tawny Emperors, Question Marks, Red Admirals, and Mourning Cloaks. I also get a few hummingbird moths, like the Nessus Sphinx I had this last summer in the garden. They are one of a few sphinx moths that fly during the day and they are so pretty!

Susan