Stretching the potting soil

 Plant your petunias in a pot partially packed with plastic packing peanuts. (Yeah, I like alliteration!)

Container plantings are a big part of summer around here. And those big pots can consume a lot of soilless mix. Here's a tip for reducing the amount of potting soil you use that I originally posted in comments at awaytogarden. It bears repeating now that I'm actually putting my containers together.

Take some plastic mesh vegetable bags and fill 'em with packing peanuts. Stuff the bag in the bottom of the pot so that it's about one-third to maybe one-half filled. Fill the rest of the container with soilless mix and plant as usual. Because the peanuts are in a bag, it's easy to separate peanuts from potting soil when emptying containers in the fall. The bags of peanuts go back into the shed to be used again the next year.

I do this with the big clay pots in which I'm planting annuals that will get tossed at the end of the season. The pots don't weigh nearly as much so they're easier to move around, the plants do just fine with ordinary watering and fertilizing and I save on potting soil. However, I don't recommend this for anything that stays in the pot long-term, such as the brugmansia that is overwintered indoors or the mother plants for my scented geraniums. I also don't cheat with packing peanuts in pots that need bottom weight to balance a potentially top-heavy load such as a trellis covered with sweet peas or other vines.

No packing peanuts? I've been known to use damaged plastic six-packs or small pots to help fill out the bottom of big pots. That works just fine, too.