Picking the Best Pots for Your Plants

From terra cotta to wood to plastic, GardenWise looks at the advantages and disadvantages of planting in various types of containers.

Terra cotta (unglazed clay)

Advantages

• Come in a variety of earthy, natural tones and in many shapes and sizes
• Suitable for casual and formal settings
• Generally inexpensive
• Very porous – porosity allows for ample air circulation to roots and ready evaporation of excess moisture to keep an even temperature in the pot, even on hot days
• Terra cotta pots change in colour with age, adding to their aesthetic appeal.

Disadvantages

• Porosity makes these pots subject to frost damage or breakage, however they can be sealed using a liquid sealer to extend their life
• Terra cotta causes soil to dry out more quickly, which results in a need for more frequent watering
• These pots, especially the larger ones, are quite heavy
• They are subject to breakage and chipping
• Tip: Ask your retailer for high-temperature-fired clay pots. Low-fired pots tend to be extra porous and even more prone to frost damage (this happens when the water absorbed by the clay freezes – the resulting stress causes the pot to crack or break).

Glazed Clay

Advantages

• Available in a wide variety of colours, patterns and sizes
• Excellent water retention due to low porosity
• Provides good insulation for the protection of root systems
• Well-suited to formal settings; there are some magnificent glazed clay pots

Disadvantages

• Usually significantly more expensive than terra cotta
• Glazed pots tend to be heavier and thicker than terra cotta pots
• Subject to chipping and breakage, plus chips are generally more visible than on unglazed terra cotta, especially if the glaze is a dark colour
• Care must be taken not to overwater due to the low porosity of the pots

Wood

Advantages

• When made from rot-resistant cedar, wood containers and boxes are generally durable and stand up well to the elements
• Wood containers are reasonably light when compared to terra cotta containers of similar size
• Retains moisture well (slow evaporation) and also insulates the roots of plants
• Rustic look makes wooden containers an ideal match to wooden decks and informal garden settings, or they can be stained or painted to match the deck or house
• Containers made from wood can be constructed to almost any configuration, providing an ideal way to house many plants in a small space. They can be fitted with trellises and can be made to a height of several feet to provide a head start to plantings designed to screen an unwanted view.

Disadvantages

• Some containers are made from wood that is pressure-treated with chemical preservatives. Avoid pressure-treated wood for any container that will hold food crops
• Bottoms can rot due to moisture accumulation

Tip:

Line your wooden containers and window boxes with a layer of heavy-duty plastic, adding in a few drain holes. By doing this you will extend the life of your wood planter by as much as two years. Also, raise them 2.5 cm (1 in.) above all surfaces using small rocks, pot stands, strips of wood or inverted saucers.

Plastic

Advantages

• Generally inexpensive (although high-quality plastic can be pricey)
• Easy to clean
• Generally resistant to breaking, especially the soft nursery-style pots
• Non-porous, so the pot doesn’t dry out as quickly as unglazed clay
• Lightweight
• Available in a wide variety of colours and styles. High-quality faux terra cotta pots look like the real thing

Disadvantages

• Plastic pots are non-porous, so it is important not to overwater
• Poor-quality plastic pots can become brittle and will fade over time
• Plastic does not have strong insulating properties, making plant root systems vulnerable to extremes of heat and cold
• Terra-cotta-look plastic pots do not change with age – an advantage or disadvantage, depending on your point of view

Related stories:

List of Container Plants