Why I put plastic bottles in big pots

Use Plastic Bottles to Make Pots Lighter

I use plastic bottles to make large pots lighter before I add potting soil. It makes pots easier to carry, cuts down on the amount of soil needed, and is better for shallow-rooted succulents. Before I plant any tall or large pot, I half-fill it with tightly capped empty water bottles.
Why I put plastic bottles in big pots
Good design and aesthetics dictate that large spaces need large pots. They make a “wow” statement in any garden, patio, entryway or sunroom. Pots that aren’t in scale with a big space can be visually lost or add clutter.

Problem is, if you fill a big pot with soil, you might not be able to move it, especially after you water it. And if succulents sit atop soil that never dries, roots may rot. My solution, a result of trial-and-error, also works for window boxes.

Kalanchoe luciae

To make my deep window boxes less heavy, there’s a layer of plastic bottles beneath the soil.

Mistakes to avoid

— Initially I tried placing a succulent, still in its nursery pot, inside a tall glazed pot. The plastic rim showed, which looked tacky. I tried the nursery plant in a different large pot. The plastic pot dropped too far inside, making the succulent look like it was hiding. Not to mention I hoped to put more than one succulent in the focal-point pot. I considered half-filling it with rocks, but being denser, they’re even heavier than soil. As for lightweight organic matter, like chipped wood, it makes the soil level sink as it decomposes.
— I tried keeping the lower half of a large pot empty by using a pot saucer as a shelf inside it. It was tricky to find a saucer that fit and would rest where I wanted it to (about a foot below the rim). Plus it needed a drainage hole.
— Next I tried filling the bottom half of a large pot with styrofoam packing peanuts. Later, when I emptied the pot to reuse it, I discovered that wet soil plus styrofoam equals a sodden mess that’s no fun to dispose of.
— I also tried dumping clean items from my recycling bin into a hefty pot, but discovered that bottles and crushed cans hold soil and water—an anaerobic mix that becomes a microbial soup. Even bubble wrap, when stuffed into a pot, forms nondraining pockets.

My cheap and easy answer

I fill large pots half full with empty plastic water bottles, tightly capped. As far as roots are concerned, bottles are the same as rocks. Yet empty plastic water bottles don’t weigh anything. Some soil does fall into gaps, so it’s a good idea to pour pumice into the pot prior to adding potting soil. Pumice, a lightweight volcanic rock, absorbs excess moisture. Make sure bottles are tightly capped, so inside them is only air and the weight of the soil won’t make them collapse.
Use bottles to make pots weigh less
Empty water bottles make big pots weigh less, save on soil, prevent soggy roots, and are easy to remove when emptying the pot. Simply hose them off before returning them to your recycling bin.

Use Plastic Bottles for Lighter Pots
Step-by-step [see the video]

— Assemble your materials: Pot, plants or cuttings, empty plastic water bottles, potting soil, pumice.
— Place empty bottles in the pot to midlevel, or to about 12 inches from the rim.
— Add enough pumice to nearly cover the bottles.
Use bottles to make pots lighter
— Remove plant/s from nursery pot/s and arrange in pot.
— Add soil so the crown of the plant (where roots meet stem) is a bit lower than the rim.
     OR, if planting cuttings, simply insert them in the soil.
— Move pot to its new location. Protect flooring from drips if need be. Water lightly to settle roots.
— After a week or so, insert a wood chopstick several inches into the soil to check its dryness. If the stick comes out clean, add water until it flows out the drain hole.

Related Info on This Site:

Showcase succulents in large pots

Use pumice to make pots lighter
Books by Debra Lee Baldwin
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28 Comments

  1. Tee Henry on April 30, 2020 at 9:18 am

    Txs. Good suggestions. However, would placing plastic water bottles with cap then soil be ok. Nothing else. And would crushed bottles without cap be ok.
    Tee

    • Debra Lee Baldwin on April 30, 2020 at 9:23 am

      Hi Tee, Yes you could do soil only. Re crushed bottles without caps, I wouldn’t, because water would still get into them and get skanky.

  2. Tara on June 2, 2020 at 2:07 pm

    So, I had bottles without tops and it did leave a stinky, stanky mess. I’m assuming that I need to throw out this all out and start again, correct?

    • Debra Lee Baldwin on June 2, 2020 at 3:12 pm

      Oh, no! Yes, I’m afraid so.

  3. Mama Mace on June 19, 2020 at 3:24 pm

    Can I use lava rocks instead of pumice? I cannot find it in any of our garden and hardware stores. Thank you.

    • Debra Lee Baldwin on June 19, 2020 at 4:34 pm

      Yes, the finer the better. Pumice is volcanic rock, btw.

      • Mama Mace on June 20, 2020 at 9:48 am

        Thank you Debra! I never imagined I could work on plants and I just started now, in my 50’s. I followed your water bottle instructions and used lava rocks in a resin planter. Is there a way I can show you a picture of what I did so I can get some constructive feedback? Thanks!

        • Gordana on May 15, 2021 at 10:53 pm

          Is it necessary to remove the paper off the plastic bottles

          • Debra Lee Baldwin on May 19, 2021 at 8:55 am

            I don’t remove the bottle labels, which are generally a thin plastic. Paper might disintegrate and get a little messy at repotting time. The plants don’t care!



          • Chris Holmex on August 14, 2021 at 8:24 am

            I have a cat palm o want to put in a very large pot that has no drainage can use this method?



          • Debra Lee Baldwin on August 14, 2021 at 8:42 am

            NO. Please re-read the article. This method does NOT provide drainage. It merely makes pots lighter by using less soil.



    • Joseph Giglio on July 21, 2020 at 2:00 pm

      Hi Debra,
      The plastic window box I’m using has a water reservoir at the bottom. Can I still use the plastic water bottles idea?
      Joe

      • Debra Lee Baldwin on July 21, 2020 at 2:05 pm

        I don’t see why not. Sealed plastic bottles are basically the same (to the plant) as large stones that roots grow around. I’d be more concerned about “a water reservoir” keeping the roots soggy, leading to rot.

        • Diane Godek on May 28, 2021 at 7:04 am

          You mention succulents does this idea work vegetable and flower plants too?

          • Debra Lee Baldwin on May 31, 2021 at 7:25 pm

            Hi Diane — Succulents are shallow-rooted, and their roots are at risk of rotting when soil in a pot doesn’t go nearly dry between waterings. Vegetables and flowering shrubs, on the other hand, generally prefer deep pots and sustained soil moisture. So no, I don’t recommend the bottle technique for them.



  4. Nancy on September 12, 2020 at 3:41 pm

    Can I do this with a ceramic pot that has a built in saucer (i.e. it has a small drain hole on the side of the built in saucer? Just want to make sure it drains well with the plastic bottles and pumice.

    • Debra Lee Baldwin on September 12, 2020 at 4:55 pm

      Yes. A saucer that holds water will keep soil in the bottom of the pot wet, which can rot roots. Plastic bottles (which to roots are solid objects like rocks) and pumice, which absorbs excess moisture, should help the situation, because most of the roots will stay above them in the pot.

    • Cheryl Dailey on January 23, 2021 at 10:33 pm

      Hi Debra,
      Appreciate the how to.. And looking forward to designing and creating succulent arrangements using this method. Thank you! 😊i

  5. Jackie on September 24, 2020 at 12:42 pm

    Can I use landscape fabric over the plastic bottles

    • Debra Lee Baldwin on September 24, 2020 at 1:08 pm

      Yes but why? I can see how it might make it easier to lift the plant and root ball out of the pot later on. But soil is going to sift downward around the edges of the fabric regardless. You’re also creating a root barrier which prevents the plant from sending roots deeper, which could inhibit growth and make the plant top-heavy. Here’s the thing to remember: Bottles, when sealed tightly, are the same thing to plant roots as rocks, except they’re lightweight. Roots follow soil into crevices.

  6. Yesenia on April 13, 2021 at 7:44 am

    Hi,
    Would it be okay to use this method with plants that have lots of roots such as rosemary, mint or lavender? How about a dwarf lemon tree?

    • Debra Lee Baldwin on April 13, 2021 at 8:34 am

      Hm. They have deep, fine roots and need more moisture than succulents. Maybe OK for herbs (if you have a tall, heavy container and they get at least 6 inches of soil) but definitely not the dwarf lemon.

  7. Donna Nase on July 5, 2021 at 10:28 am

    Hi, i dont have pumice, so if i just use the bottles and soil, will that be ok? I picture the soul eventually sinking in between the bottles and maybe clogging drainage holes?? Thanks for any input.

    • Debra Lee Baldwin on July 5, 2021 at 11:47 am

      Hi Donna — It’s fine if you use potting soil (sold in bags at any nursery or garden center). It’s coarse enough that drain holes don’t get clogged by it. Put a piece of paper towel or mesh screen (or even a rock) over the hole to prevent soil from falling out. As for pumice, it’s optional. I suggested it because it’s lightweight and helps absorb excess moisture.

  8. Debbie on May 20, 2022 at 10:44 am

    Will the plastic bottles an soil work with geraniums?

    • Debra Lee Baldwin on May 23, 2022 at 8:12 am

      I don’t see why not. The point is to use less soil and make the pot lighter, and geraniums are not deeply rooted.

  9. Roselyne Durand Ruel on June 22, 2022 at 10:32 am

    Good afternoon. Is it ok to use a large tall planter filled with 100% recycled plastic bottles in order to grow tomatoes? Thank you

    • Debra Lee Baldwin on June 22, 2022 at 10:49 am

      Hi Roselyne — Tomatoes have deep roots. I’d be concerned that the bottles would take up too much soil space. Soil also retains water, and tomatoes are much more thirsty than succulents. But I suppose it wouldn’t hurt to give it a try. After all, roots will go around the bottles, just as they would similarly-sized rocks. You can water more often. I’d love to know if you try it and are pleased with the results.

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