Concrete in Plastic Planters: Can it be done?

Question: Can you Put Cement in Plastic Pots?

ANSWER: Yes, it is possible to put concrete in a plastic planter for the short term. The concrete will mold to the shape of your plastic planter and set neatly at the bottom. However, over time, the alkaline content of the concrete may gradually cause your plastic planter to deteriorate and crack. So concrete in plastic planters may be okay for short-term projects. However, overtime may cause some issues. We’ll discuss alternatives later in this article.

Can You Put Cement in Plastic Pots

Welcome to today’s feature article at the Garden Bench. We’ll explore the question, ‘Can you put cement in Plastic Pots?‘ You can expect to learn:

  • the reasons why you want to put cement in planters,
  • alternatives to using concrete in planters, and
  • common questions surrounding the use of cement in planters.

So put on your high-visibility vest and protective glasses because we’re about to start.

Why Put Cement in Plastic Planters?

Cement is a versatile material that has many gardening applications.

It is moldable and easy to produce for DIY projects, which makes it perfect for the home gardener. For example, you can use it to help set garden ornaments in loose potting mix or make concrete pots or boxes for the new plants you purchased at the nursery.

In this article, we’ll explore the uses of cement in plastic planters.

Weigh it Down

One of the most frustrating experiences with outdoor planters is when they continuously get blown over by the wind, especially when you have beautiful tall potted plants.

Not only does it make a mess with all the topsoil scattered on the ground, but it can also cause damage to your plants and break the planter.

The problem is that there is not enough weight between the plant and the soil. The issue gets exacerbated when the plant is top-heavy.

A straightforward solution is adding cement to the plastic planter’s bottom to increase the weight. Adding cement will decrease the chances of wind pushing it over. And, in the case of top-heavy plants, it will help to move the center of gravity lower.

This also works for weighing down fake plants.

IMPORTANT: Ensure you maintain holes in the cement to allow any excess water to drain (not applicable to fake plants for obvious reasons).

Space Filler

Sometimes filling planters with cement helps to act as a space filler – especially for larger plastic planters like the one pictured below.

Fill Large Planters with Cement

It is an economical alternative to filling the entire planter with potting soil or other costly organic materials.

Elevation for Faux Plants

Admittedly, we don’t usually talk about faux plants. However, we couldn’t resist including this tip when using cement in plastic planters.

As their name suggests, fake plants (or plastic plants) don’t grow. So it isn’t easy to achieve your overall look without a few adjustments. Sometimes they sit too low in your planters, which looks odd.

To raise them to the right level, try setting some cement at the planter’s base until your faux plant sits at the correct level.

You can fill the remaining space with styrofoam or foam blocks and dress the top with fake grass to produce a beautiful, low-maintenance indoor (artificial) plant like the one pictured below.

Beautiful Artificial Plant
credit: pinterest

Alternatives to Cement in Plastic Planters

If you prefer an alternate option to pour cement in plastic containers but still want to retain the benefits that we discussed earlier, try these options:

  • Large garden stones are a great option because they should already be readily available in your garden and have the necessary weight to prevent your planters from toppling over in the wind.
  • House bricks – for large plastic planters, you can choose a standard house brick as a good substitute for cement. Not only does it achieve the same outcomes, but it also saves you the hassle of creating drainage holes in your cement.
  • Styrofoam – this substitute only applies to plastic plants you want to raise to a suitable level in your planters. We like styrofoam because it is a simple and effective fix, plus it also means you have upcycled a piece of trash that usually ends up as landfill.

Concrete in Plastic Planters: Common Questions

Can I Put Quikrete in a Planter?

Yes – you can put Quikrete in a plastic planter. It is a quick solution to filling your plastic planter and doesn’t require as much manual labor as a regular cement mix. It is also a good option for making your own concrete planters or cement pots.

What Kind of Cement Do You Use for Planters?

The cement you should use in planters should be finely ground powder that will produce a consistent, smooth finish. Even though it is suitable, the larger grain cement and other chunky materials will not be as aesthetically appealing.

It would help if you also used dry cement because it is less caustic than wet cement. Wet cement contains higher levels of calcium oxide, which produces calcium hydroxide when it comes in contact with water. Calcium hydroxide accelerates the disintegration of your plastic planter.