Q: I have a big pot from which I’ve pulled all of the petunias and other summer annuals. I want to plant it with pansies but I don’t know what to do with the old soil. Do I have to dump it out and replace it with fresh potting soil?
A: The old potting soil didn’t become “used up” by having been home to your summer flowers. The only likely thing that could be wrong with it is the possibility that it has an excess of unused fertilizer from the summer. That condition is easy to cure: just saturate the soil with water, let it drain, then repeat twice more. You can do it in an afternoon. You can then plant your plants for winter color in the same pot using the same soil.
Don’t forget the basics of potted plant design: “something tall, something green and something blooming”. You could easily have a great looking pot by planting a purple ornamental cabbage in the center, surrounding it with green parsley and using pansies or violas around the edge. Since I have no talent for design, these little rules are all that save me sometimes.