foam planter pots

Using Styrofoam In Containers – Does Styrofoam Help With Drainage

Whether set on a patio, porch, in the garden, or on each side of an entryway, stunning container designs make a statement. Containers are available in a wide array of colors shapes and sizes. Large urns and tall decorative glazed pots are especially popular these days. While decorative pots like this add to the beautiful dramatic appearance of container gardens, they have some drawbacks.

When filled with potting medium, large pots can be extremely heavy and unmovable. Many glazed decorative pots may also lack proper drainage holes or do not drain well due to all the potting mix. Not to mention, purchasing enough potting soil to fill large pots can become quite expensive. So what’s a gardener to do? Read on to learn more about using Styrofoam for container filler.

Using Styrofoam in Containers

In the past, it was recommended that broken pieces of clay pots, rocks, wood chips or Styrofoam packing peanuts be placed in the bottom of pots as filler and to improve drainage. However, research has shown that clay pots, rocks and wood chips may actually cause the pots to drain slower. They can also add weight to the container. Styrofoam is lightweight but does Styrofoam help with drainage?

For decades, container gardeners have used Styrofoam for drainage. It was long lasting, improved drainage, did not add weight to the pot and made an effective filler for deep pots. However, because landfills are overfilled with non-biodegradable products, many Styrofoam packing products are now made to dissolve in time. It is not recommended to use Styrofoam peanuts for potted plants now, because they may break down in water and soil, leaving you with sunken in containers.

If you find yourself with a large amount of Styrofoam from product packing and question: “Should I line potted plants with Styrofoam,” there is a way to test the Styrofoam. Soaking these packing peanuts or broken bits of Styrofoam in a tub of water for several days can help you determine if the type you have breaks down or not. If pieces begin to dissolve in the water, do not use them in the bottom of pots.

Does Styrofoam Help With Drainage?

Another problem gardeners have had when using Styrofoam in containers is that deep plant roots may grow down into the Styrofoam. In pots with little to no drainage, the area of Styrofoam may be waterlogged and cause these plant roots to rot or die.

Styrofoam also contains no nutrients for plant roots to absorb. Too much water and lack of nutrients can cause beautiful container designs to suddenly wilt and die.

It is actually recommended that large containers be planted in the “container in a container” method, where an inexpensive plastic pot is planted with the plants, then set atop filler (like Styrofoam) in the large decorative container. With this method, container designs can easily be changed out each season, plant roots are contained within the potting mix and, if Styrofoam filler does break down in time, it can be easily fixed.

When filled with potting medium, large pots can be extremely heavy. Many also lack proper drainage holes or don?t drain well. Not to mention, potting soil to fill them can become quite expensive. What?s a gardener to do? Learn about using Styrofoam for container filler here.

Polyurethan Foam Planters

Has anyone used polyurethane foam planters?

What are their real advantages? The ads say they’re lightweight and holes can easily be drilled in them for drainage. Are they strong and sturdy?

They’re very expensive in the ads I’ve seen, yet plastic products are among the cheapest of all products to produce, so I suspect someone is making a tidy profit from them.


I recently purchased a large foam planter on sale at a Michaels craft store. It is called Gardien Glazed Planters by Consolidated Foam, Inc. and was made in China. I was planning to pot up some culinary herbs in it. I don’t know anything about the material, and I’m wondering if there is a chance of chemicals leaching into the soil.

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I’m not sure the exact type of planter I have. I know it’s a foam of some type. I purchased mine at JoAnn’s and then used a drill to make a few holes in the bottom. I bought about six of these last year and had them out all season. In fact, they’re still out on the patio now.

They held up really well. My only complaint is that they’re easy to damage. I was digging up some gladioli corms and accidentally cracked one of the pots. Granted, I was using a shovel against the side of the pot as leverage, so it was my fault. But otherwise, they worked out wonderfully.

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Maybe what you have are those polyurethane foam planters.

I looked up the foam itself on the internet and apparently there are at least three grades or strengths of it. Products made from the first two can be “dented” with a fingernail, though the highest grade was advertised to be very tough.

I’m not sure I’ve ever examined one. They sound like tough styrofoam to me, lightweight, drillable, don’t heat up in the sun, etc. I was just curious about how they hold up. Sounds like the one you had could have been sturdier!

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I’ve done a lot of research on polyurethane pots, as I’m trying to switch all my terra cotta pots to polyurethane.

Here’s what I’ve learned.

Polyurethane pots can be almost indistinguishable from terra cotta, stone or cement pots, except that the polyurethane containers are much, much lighter, and have some other valuable benefits. Polyurethane is up to an inch thick and has the feel of hardened styrene foam. It is a good insulator that will keep plant roots from overheating in summer and help extend the season in fall. Most pots are guaranteed for at least 36 months against chipping, cracking, fading and freeze damage. They can by easily drilled for drainage, if they don’t already have a drainage hole in the bottom.

Polyethylene is another option. Polyethylene may appear indistinguishable from terra-cotta on the outside, but the rim is rolled over to the inside to make it appear as thick as terra cotta. The rest of the pot wall is only 1/4 to 3/8 inch thick. Despite its thinness (which makes it lightweight) the material is tough, resisting damage from sun and frost. Although this type of pot is good-looking, it doesn’t have the insulating capacity of the polyurethane pots. These normally have pre-drilled holes.

I’ve also run across the terms “resin” and “fiberglass,” and I’m trying to figure out if either means the same as polyurethane. Also, I’ve noticed that most of the staff at my local garden centers have no clue about how to identify a polyurethane pot, and are as likely to point me to a polyethylene or plastic choice.

I haven’t yet been able to find someplace – online or otherwise – to purchase simple faux terra cotta (no carved grape leaves, etc.) polyurethane pots in a variety of sizes. Any tips would be welcome!

Has anyone used polyurethane foam planters? What are their real advantages? The ads say they're lightweight and holes can easily be drilled in them for drainage. Are they strong and sturdy? They're very expensive in the ads I've seen, yet plastic products are among the cheapest of all products to pr…