Should most plants be pruned in Fall?

What plants are you referring to?

I'm not a real gardener, but I do keep plants and shrubs in my yard. It has been my experience that pruning should be done during milder weather conditions. The plant suffers a bit when pruned - kind of like same day surgery - you need a few days to get back to normal. Extreme weather conditions like heat or frost could permanently damage the plant during this time of weakness.

You should research your plants and shrubs INDIVIDUALLY. Some shrubs grow from old wood, some sprout completely new. Real damage can be done if pruned incorrectly. But, I agree, save any trimming to cooler temperatures, not 90 degree weeks.

As Patty said above, research. A quick rule of thumb is to trim all blooming shrubs immediately after the bloom is finished. This allows for new growth prior to the next years bloom. Some shrubs can be shaped and pruned as needed, but be aware of extreme conditions Heat and drought. If your plants are stressed cutting them back can at times save it's life expectancy. If in doubt contact a local nursery or Master Gardeners group, they are always will to offer tips.