The peanut option works well to take up space in large containers. You need to be sure to use Styrofoam peanuts (these won't retain moisture) rather than the biodegradable "starch based" peanuts. Put a layer of fiberglass screen between the peanuts and soil. Also keep in mind that this will raise the center of gravity for the pot. If you have tall plants they will be more likely to tip over in the wind since the base is lighter.

Good luck, Pat

I use styrofoam peanuts all of the time because I have a garden of about 30 containers on my wooden deck so weight is definitely a concern. I have not had any problems with water absorption or rot and I've been doing this for about 6 years. The amount I use in large containers depends on what I'm planting. In my pots with Japanese Maple or rose shrubs, I may only fill 1/3 with peanuts. For pots with smaller perennials and annuals, then maybe half. Not only will you decrease weight but you'll spend less money!

Good luck!

Here is a link that might be useful: Flat Bottom Flowers

I use upside down nursery pots. This has worked well for me for the last few years.

I haven't tried this, but I read it somewhere recently...try using plastic milk jugs..the peanuts can be a huge mess when emptying out containers (I do know that from experience...they go all over the place). Also if you fill the jugs with water, you lower the center of gravity and they are less likely to topple...toppling containers is an issue for me because I live where it can get quite windy. I wish I had read about this earlier in the season, but my containers are done for the year.

Thanks for the responses! Very much appreciated, and I will try all suggestions.

Sadly, my impatience to get my flowers planted got the best of me, and I loaded up 2 containers with potting soil. Bad idea. After watering, they must weigh 80 lbs. Never again!

Thanks for the link, fbflowers. I can't wait to put a Japanese Maple in a container! I love them, but I'm planning a move and don't want to invest in things I can't take with me.

And I agree with you on zinnias. Love 'em, they never fail me. :)

I just put a large black nursery container upside down and then place the plant on top in another black nursery container. Depending on the pot, you can put one plant in the center and others around the outside, or you can put several in at once for a more crowded look. If you need to cover the containers consider sheet moss. Then if something doesn't look great anymore, just switch out the plants with fresh ones kept in their nursery containers.