Should You Put Rocks at the Bottom of a Planter? We Asked an Expert

We all want what is best for our beloved houseplants. So, if there’s a chance that putting rocks at the bottom of a planter is going to help them flourish, any good plant parent would do it, right?

It turns out there are certain situations that may call for rocks and many that don’t—the determining factor primarily lies in the planter’s design.

Here, we asked an expert to offer insight into whether or not adding rocks is important.

Should You Put Rocks at the Bottom of a Planter?

Putting rocks in the bottom of a planter is a bit of a hot topic in the houseplant world. Sabharwal is team “add rocks”, but only in one situation in particular.

For context, adding rocks to the bottom of a planter is said to prevent root rot. “It creates a bit of airflow, especially in pots that don’t have a drainage hole,” he says.

So, Sabharwal says it’s a good idea to put a layer of rocks in a planter with a solid base. If you often find yourself being a bit too generous with your watering, the use of rocks could be a game-changer. They can help counteract the adverse effects of overwatering.

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Don’t Put Rocks in Planters With a Drainage Hole

Drainage holes in planters also serve a purpose, which is to allow excess water to escape. This also prevents root rot.

Sabharwal notes that putting rocks in the bottom of a planter with a drain hole is unnecessary. In fact, it can actually prevent excess water from exiting, since rocks obstruct the drainage hole.

Do Certain Plants Require Rocks?

As it turns out, houseplant type doesn’t have a big impact on whether or not you should put rocks in the bottom of the planter.

“The need for rock depends on the type of planter and its drainage capabilities rather than the plant species,” Sabharwal says. “However, for plants that are very sensitive to overwatering, like succulents, using rocks can help prevent water from gathering at the base and causing root rot.”

If you’ve got a few pots on hand that don’t have a drainage hole, you can still put them to good use, and you can try a layer of rocks. Use small pieces of gravel or pebbles rather than large rocks at the bottom of the planter, and keep it to just about 1-2 inches.

2 Alternatives to Using Rocks

Drill Your Own Holes

Instead of adding rocks to a planter without a drainage hole, you can make holes of your own. This is especially easy if your planter is made from wood or plastic because any drill bit will work. However, drilling through metal pots requires a cobalt drill bit.

As far as drilling a ceramic pot goes, the process is just a bit more involved—we’ve got an entire tutorial. We recommend drilling just one large hole in the middle instead of several smaller holes.

Use Two Pots

Another workaround for still getting use out of your decorative drain-hole-free pots is the two-pot method. Simply plant your houseplant in a pot with a drainage hole that is slightly smaller than your decorative pot.

Then, place it inside the decorative pot. Just be sure to remove it from the decorative pot when you water it. Place it back inside after all the water has drained out.

Bottom Line on Rocks

In general, it’s not necessary to put rocks in the bottom of your planter to prevent root rot. If your pot doesn’t feature a drainage hole, you can drill one or use the two-pot method.