Q: I have large planters on my porch. Do you have any tips for a space filler at the bottom other than potting soil?

A: I use two-liter soft drink bottle filled with sand and capped. Most container plants have roots that extend downward no more than twelve inches. Soil below that point contributes nothing to the plants. I’ve heard of gardeners using packing peanuts to fill the bottom but sometimes the foam pieces float to the top of the soil.