When planting, we recommend using a “Lightweight Filler” to decrease the overall weight of the planter. Larger planters and window boxes can take bags and bags of soil which is not only expensive but can also be very heavy. For window boxes, this puts extra stress on the mounting brackets holding your box up. The weight of the soil is heavy to move, and may also cause issues of the weight compressing and compacting the soil affecting drainage and root growth. To solve these issues try using a lightweight filler to fill the bottom of your planters.
What can be used?
- Styrofoam packing peanuts (NON-BIODEGRADEABLE) or other broken up Styrofoam packaging
- Empty Water/pop Bottles with the lids on
- Pearlite or Vermiculite
- Lava rock
- More ideas here http://www.thriftyfun.com/Filler-Ideas-for-Potted-Plants.html#solutions