Terracotta vs. Plastic Pots for Houseplants: Which to Use

Terracotta or Plastic: The Short Answer

Use terracotta for houseplants that need to dry out between waterings, and plastic for houseplants that like to stay moist. Unglazed clay is porous, so it absorbs and loses moisture through its walls and the potting mix dries quickly. Plastic is nonporous, so plants in it need less frequent watering. Cacti, succulents and anything you tend to overwater belong in terracotta. Ferns, calatheas, peace lilies and anything you tend to forget belong in plastic.

Your watering habit counts as much as the plant. A pothos in a 6 inch pot will grow in either material, but it will want water sooner in clay than in plastic, and the right choice is the one whose schedule you will actually keep.

How the Two Materials Compare

Factor	Unglazed terracotta	Plastic
Moisture	Absorbs and loses water through the walls; dries rapidly	Holds moisture; less frequent watering
Air to roots	Excellent aeration	Air enters only from the surface and drainage holes
Salts	Clay pulls water and soluble salts out of the mix; a white film forms on the outside	Nonporous walls stay clean; a crust can still form on the surface of the mix
Weight	Heavier than plastic, lighter than stone	Lightweight and easy to handle
Breakage	Easily cracked or broken	Flexible, though it can turn brittle outdoors in cold weather
Removing the plant	Rigid walls make a root-bound plant hard to slide out	Walls flex, so the root ball releases
Cost	Higher	Lower than terracotta and glazed pottery
Before first use	Soak overnight	Check that it has drainage holes

The moisture and air rows drive plant health. The rest are about convenience, and they matter more as pots get bigger: a 12 inch clay pot full of wet mix is a two-handed lift, while the same size in plastic moves easily to the sink.

Terracotta: Fast Drying and Good Aeration

The University of Maryland Extension sums up clay pots in one line: they easily absorb and lose moisture and provide excellent aeration for plant roots. Water leaves a terracotta pot in three directions, out of the drainage hole, up from the surface, and sideways through the wall. Penn State Extension adds that the clay tends to pull water and soluble salts out of the potting mix, which reduces waterlogging.

That is the property that protects a plant from a heavy hand with the watering can. It is also the drawback. Maryland lists the downsides as pots that dry out rapidly, break easily, and have rigid walls that make a plant difficult to remove. Penn State puts the consequence plainly: plants in clay containers need to be watered more often than plants in plastic ones.

New clay needs one step before planting. A dry unglazed pot will draw moisture out of fresh potting mix, so Penn State recommends soaking a new porous container in water overnight. Iowa State University gives the same advice for cleaned pots: leave them in a bucket of clean water until you are ready to plant.

Plastic: Holds Moisture, Light to Handle

Plastic keeps water in the mix. Penn State calls it ideal for plants that like to remain moist, and it is lightweight, which Penn State calls a distinct advantage when you must move a pot holding the plant, the potting mix and water. The same lightness helps with hanging baskets and high shelves. It also costs less than terracotta or glazed pottery. Iowa State suggests judging quality by the thickness and flexibility of the walls, and notes that durability and thickness rise with price.

The risk with plastic is the mirror image of its benefit. With no loss through the walls, a mix that is watered on a fixed weekly schedule can stay wet at the bottom, and roots sitting in wet mix rot. Two habits prevent that. Check the mix with a finger before you water, and make sure the pot drains, because Maryland notes that plastic pots occasionally lack drainage holes. A container with drainage holes is necessary for excess water to leave, whatever the material. If a plant is already suffering, see how to save an overwatered houseplant.

Which Houseplants Go in Which Pot

Match the pot to how dry the plant wants its roots. Cacti, succulents such as jade plant and echeveria, and snake plants are grown in fast-draining mix and watered only after it dries, so terracotta works with them. Pair it with the right mix, covered in best potting mix for succulents and cacti.

Boston ferns, calatheas and peace lilies wilt or brown at the edges when the mix dries out, so plastic gives them a longer margin between waterings. Pothos, heartleaf philodendron and spider plants tolerate either. For those, choose by habit: clay if you water often, plastic if you water late.

A common compromise is to keep the plant in a plastic grow pot and set it inside a heavier decorative pot. The roots get the slow drying of plastic and the plant gets a stable base. Take the inner pot out to water and let it drain completely before it goes back, so the plant never stands in a pool at the bottom of the outer pot.

White Crust, Cleaning and Reuse

The white film on the outside of a terracotta pot is mineral and fertilizer salt that traveled through the clay with the water. The same crust can form on the surface of the mix in any pot. It is a signal worth acting on, because Maryland notes that salt deposits compete with the plant for available moisture and can dry out or burn tissue. When a crust forms on the outside of a pot, Maryland’s advice is to move the plant into a fresh pot; the old one can be soaked, scrubbed with a brush and reused.

Maryland’s remedy for buildup applies to both pot types: every 4 to 6 months, leach the plant with clear water, pouring through at least 3 times the volume of the pot and letting it drain completely. To clean an empty clay pot, Iowa State recommends steel wool or a wire-bristle brush for the deposits. Before reusing any pot for a new plant, disinfect it for at least 10 minutes in a solution of one part household bleach to nine parts water, then rinse.

Choosing the Pot Size

Material does not change the sizing rule. When you repot, move to a container only slightly larger than the current one, set the top of the root ball about an inch below the lip, and leave that inch of space above the mix for watering. A pot that is far too large holds wet mix the roots cannot reach, and plastic makes that problem worse while terracotta softens it. How to choose pot size for houseplants gives the step sizes, and when to repot a houseplant lists the signs that it is time. If you are also weighing fabric pots, see terracotta vs. plastic vs. fabric pots.