Does a plant go to sleep faster than it wakes up? Does gravity help a root grow deeper and pull the summer's energy downward? The gardener wonders about these things as they find a unanimous shift of leaf color and plant vigor in fall. In our fields the corn and soybean yellow in unison. It's a steady, slow, gentle change. We are in a dry period, spoiled after a summer with rain. We are also in a warm period, above average temperatures for fall. I can say with certainty that rain will come and cold will too. I can also say, based on years of observation, that a plant will do things differently with wet soil or rain. Rain helps move things along and in my mind it's an aid in furthering dormancy, like the well has been filled.
Keeping that in mind, the gradual change seems to be moving slowly. I fret there will be lots of rain, eventually, and the potential for a rapid temperature drop. As the gardener makes plans, we tend to look to the future; the houseplants that have summered outdoors will have to come in. It's a great time to unpot them, slip them out of their container and check for ants or other occupants. Too often I have brought a colony of ants inside. The simplest solution is to just rest the root ball on the ground. Ants will vacate in an orderly fashion with all of their babies. Check the bottom of the root ball occasionally to make certain. This is better done without a looming frost and the need for urgency.
If you are digging larger tropicals from out of the ground, take an inventory of pots you will need to lift them into. There is nothing worse than cramming a luxuriant tropical into a much smaller pot and thinking it will handle it well. You may also want to sink a shovel into the ground at the edge of the root ball you plan on digging. Don't lift the whole plant (yet), just begin the process by breaking some roots. Sort of like studying for the exam, the real physical one where you will dig and repot.
As temperatures fall at night, your tropicals will be fine with 50 degrees. Forty degrees is entirely different, for them it's winter. The only exceptions to this rule (and I'm sure there are plenty more) are amaryllis and cymbidium orchids. Leave them out till we flirt with temperatures in the high thirties. It sets them up nicely for winter flowers. Both amaryllis and cymbidiums are much better plants if they get to spend their summer's outdoors. Much like the gardener!