If you use this option, you’ll also want to have a layer of newspaper, landscaping fabric, or cheesecloth available to lay down on top of your bottles or cans before adding your soil.
If your large planter has drainage holes along the bottom edges, avoid blocking them with the top edges of your smaller pot. You’ll need to be sure that water can still drain through the bottom of your planter. If your smaller pot is significantly smaller than your larger planter, you’ll want to hold it in place with another material like clay pebbles or wood chips. This will also help to lessen the amount of soil you’ll need when filling your planter.
Avoid this option if the drainage holes of your tall planter are in the middle of your planter’s bottom. The wood will cover the holes and not allow your soil to drain properly. You can use wood chips, clay pebbles, or soil to hold the wood beam in place in the center of your planter.
This option works well if your tall planter becomes narrower at the bottom and you’re concerned about it tipping over from the weight of your soil and plant at the top. Be sure that your rocks are not covering any drainage holes in the bottom of your planter.
Use mesh onion bags to hold the packing peanuts in place and avoid making a mess when you replace your plant’s topsoil each year. You can also try cutting up larger pieces of Styrofoam packaging and filling your planter with these pieces.
If you’re using jugs or containers, be sure not to block any of the drainage holes in the bottom of your planter. Space the jugs or containers out so they’re not blocking the holes.
6-8 holes should be enough for most tall planters, but you can make more if your planter is wide or it seems like it could use more. Always use eye protection and gloves when using power tools.
For example, if your planter is 21 inches (53 cm) tall, and the soil of your plant is about 7 inches (18 cm) deep, you can either fill the bottom remaining 14 inches (36 cm) with filler, or fill the bottom 10. 5 inches (27 cm), which is half the planter, depending on your preference.
You also have the option of using wood chips instead of clay pebbles. These will need to be replaced each year because water can cause them to rot.
On the other hand, if the plant appears to be root-bound in its current container, loosen the roots gently outwards with your fingers. A root-bound plant will have visible roots that coil around the inside of the pot.
Change your bottom filler if you used wood and it’s starting to rot, or become squishy and smelly; and change out aluminum cans if they are starting to rust. Plastic items and Styrofoam generally last a long time, but it doesn’t hurt to check on them and see if they are breaking down and could be replaced. Rocks, broken pottery, and clay pebbles will be the materials that last the longest out of your bottom fillers.
If you used a mix like Miracle-Gro, it is likelier that you will need to replace the soil every year. Consider replacing it with living or organic soil.
