A collection of cacti and succulents in terracotta containers at The Living Desert, Arizona. Photo Amanda Jarrett
Pot feet keep planters off surfaces and are often quite decorative.
Black pots absorb heat, which this Little Bites window box cherry tomato appreciates.
Trays with wheels are perfect for moving heavy planters around.
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Choosing a Container
Concrete, plastic, ceramic, wood, fiberglass, Styrofoam and metal are common planter material. There’s so many types, trying to find the right one for a specific plant, location or function, can be daunting. This article explores the pluses and minuses of the different types of containers: terracotta (unglazed clay), glazed clay, stone, wood, metal, fiberglass, polystyrene, concrete, self-watering pots and hanging pots. Protect your Deck & Patio No matter what kind of container you use, keeping them off the ground is recommended. Not only does this prevent slugs and bugs from climbing up, it also protects deck surfaces. Pot feet raise the bottom of pots just a few inches. Use 4, but space them evenly at the bottom of the pot or drainage tray. Look for decorative ones, designed like little frogs or bunny rabbits. Cute! If you want to move plants around to follow the sun, or for whatever the reason, bypass the pot feet and opt of a tray that has wheels. These handy trays are available at dollar stores and often where planters are sold. Black Pots Just a quick word about colour – it does make a difference. Black and dark containers absorb heat so they become quite hot when sitting in the sun. Plants often don’t mind when temperatures are cool and neither do heat loving plant such as tomatoes, peppers, herbs and succulents, however if the pots get too hot, so does everything inside it. Hot soil increases evaporation resulting in extra watering. Roots may also get so hot they will actually die back. Cool season crops such as lettuce, broccoli and peas will mature faster. The lettuce will bolt and taste bitter, the broccoli heads blossom and the peas won’t be as tasty. Be sure to do your research to find out where a plant comes from to determine if it likes it hot or not. Go to Growing Food for more information. |
Terra cotta pots are perfect for sun loving dianthus.
Terracotta (unglazed clay)
Terracotta pots are made from clay and are easy to find, inexpensive and get a nice patina as they age. These are heavy pots are an excellent choice if wind is a problem, but large ones are not easy to move. Because they are made of clay, they are porous and allow the transfer of water and air through to the roots. This means you have to water more often but, with that said, they are perfect for cacti and succulents. To decrease a clay pot’s porosity so you don’t have water so often, paint the inside of the pot with terracotta sealer, available at home hardware stores. There are some clay pots are more porous and fragile than others. Low-fired clay pots are extra porous and prone to frost damage compared to high-temperature fired ones, so ask before buying. Price is a good indicator of quality. On the con side, terracotta pots break easily and salts build up (white powdery stuff) on their rims. A big issue is they are prone to cracking. This is a big problem in climates where the temperatures fluctuate. Because clay pots are porous they dry out quickly, so submerge clay pots in water before planting them up. Once bubbles stop they are ready to pot up. Note that plants in clay pots need frequent watering due to the porous nature of the clay. A drainage tray is a good idea to aid with soaking up extra water.
Glazed Clay
Glazed clay pots are very popular, are easy to find and are reasonably priced. They come in a myriad of colours, shapes and designs. They have a good weight to them so they don’t easily fall over, however, really large ones are difficult to move. The glaze seals the pots so they have good water retention but since there is not air exchange they are easy to overwater. Generally, they are not as suitable for cacti and succulents like unglazed clay due to the lack of air exchange. As anyone will attest to, glazed clay chips and cracks easily when temperatures fluctuate. They are not the best choice of pot for keeping outside in cold climates.
Terracotta pots are made from clay and are easy to find, inexpensive and get a nice patina as they age. These are heavy pots are an excellent choice if wind is a problem, but large ones are not easy to move. Because they are made of clay, they are porous and allow the transfer of water and air through to the roots. This means you have to water more often but, with that said, they are perfect for cacti and succulents. To decrease a clay pot’s porosity so you don’t have water so often, paint the inside of the pot with terracotta sealer, available at home hardware stores. There are some clay pots are more porous and fragile than others. Low-fired clay pots are extra porous and prone to frost damage compared to high-temperature fired ones, so ask before buying. Price is a good indicator of quality. On the con side, terracotta pots break easily and salts build up (white powdery stuff) on their rims. A big issue is they are prone to cracking. This is a big problem in climates where the temperatures fluctuate. Because clay pots are porous they dry out quickly, so submerge clay pots in water before planting them up. Once bubbles stop they are ready to pot up. Note that plants in clay pots need frequent watering due to the porous nature of the clay. A drainage tray is a good idea to aid with soaking up extra water.
Glazed Clay
Glazed clay pots are very popular, are easy to find and are reasonably priced. They come in a myriad of colours, shapes and designs. They have a good weight to them so they don’t easily fall over, however, really large ones are difficult to move. The glaze seals the pots so they have good water retention but since there is not air exchange they are easy to overwater. Generally, they are not as suitable for cacti and succulents like unglazed clay due to the lack of air exchange. As anyone will attest to, glazed clay chips and cracks easily when temperatures fluctuate. They are not the best choice of pot for keeping outside in cold climates.
A wood barrel filled with bergenias.
Stone Containers
Stone containers have an old world look that are very durable and last for years. Either made from a solid piece of stone or cast in a mold, they tend to resemble ancient relics. Maybe that’s why they can be quite expensive. Their insulation value is good, especially thick ones, but they are very difficult to move because of their weight. Once placed, they are usually are too cumbersome to move elsewhere and become permanent fixtures.
Wooden Containers
Planters made of wood are easy to make and are inexpensive. They can be painted, stained and decorated to match anyone’s tastes from rustic to elegant Wood is a good insulator and is generally lighter than concrete and stone. The type of wood is an important part of how the planter will withstand being outside all year and being filled with wet soil. Use rot-resistant wood: cedar, teak and redwood. Pressure treated wood is not suitable for food crops including fruit trees. To prolong the life of all wood, seal the joints with a polyurethane or silicone based caulk to prevent soil penetrating the crevices. For non-painted or stained wooden planters, coat all surfaces with Danish oil or an oil based urethane wood stain. Follow up with a layer of heavy-duty plastic then punch in a few holes to allow for drainage or place a plastic pot inside the planter. It is cheating, but it works. Raise wooden planters off the ground with pot feet or a planter dolly to prevent the bottom from rotting. Add wheels so you can move it around.
Stone containers have an old world look that are very durable and last for years. Either made from a solid piece of stone or cast in a mold, they tend to resemble ancient relics. Maybe that’s why they can be quite expensive. Their insulation value is good, especially thick ones, but they are very difficult to move because of their weight. Once placed, they are usually are too cumbersome to move elsewhere and become permanent fixtures.
Wooden Containers
Planters made of wood are easy to make and are inexpensive. They can be painted, stained and decorated to match anyone’s tastes from rustic to elegant Wood is a good insulator and is generally lighter than concrete and stone. The type of wood is an important part of how the planter will withstand being outside all year and being filled with wet soil. Use rot-resistant wood: cedar, teak and redwood. Pressure treated wood is not suitable for food crops including fruit trees. To prolong the life of all wood, seal the joints with a polyurethane or silicone based caulk to prevent soil penetrating the crevices. For non-painted or stained wooden planters, coat all surfaces with Danish oil or an oil based urethane wood stain. Follow up with a layer of heavy-duty plastic then punch in a few holes to allow for drainage or place a plastic pot inside the planter. It is cheating, but it works. Raise wooden planters off the ground with pot feet or a planter dolly to prevent the bottom from rotting. Add wheels so you can move it around.
A metal container at VanDusen Botanical Garden.
Plastic Containers
Plastic containers are found everywhere, and because they are inexpensive, and come in all shapes, sizes, styles and colours they the most common type of planter. Since they are non-porous, they retain water, which reduces the need to irrigate, but it also leads to overwatering. Plastic planters are not durable. They will chip, split and fade overtime, however, not all plastic is created equal. All types becomes brittle and degrade in the sun, but inexpensive ones usually only lasts a couple of years. Plastic containers are generally lightweight, so they are easy to move, but are easily blown over. They have a short life span and don’t age gracefully.
Metal Containers
Metal containers with their clean lines denote a modern, chic look. They are often lightweight and they don’t break or chip, but they are easily dented. Choose stainless steel or galvanized metal so they don’t rust. There’s also pre-coated steel that’s anti-corrosive, recyclable and durable. Powder coated metal is another option which has a rustproof coating. Metal become icy cold in the winter and painfully hot in the summer so it has little insulating value. It is good idea to double pot, by placing a pot with better insulating value, inside metal one. Generally they are not suitable for perennials, trees or shrubs because they are too hot in summer and too cold in winter.
Plastic containers are found everywhere, and because they are inexpensive, and come in all shapes, sizes, styles and colours they the most common type of planter. Since they are non-porous, they retain water, which reduces the need to irrigate, but it also leads to overwatering. Plastic planters are not durable. They will chip, split and fade overtime, however, not all plastic is created equal. All types becomes brittle and degrade in the sun, but inexpensive ones usually only lasts a couple of years. Plastic containers are generally lightweight, so they are easy to move, but are easily blown over. They have a short life span and don’t age gracefully.
Metal Containers
Metal containers with their clean lines denote a modern, chic look. They are often lightweight and they don’t break or chip, but they are easily dented. Choose stainless steel or galvanized metal so they don’t rust. There’s also pre-coated steel that’s anti-corrosive, recyclable and durable. Powder coated metal is another option which has a rustproof coating. Metal become icy cold in the winter and painfully hot in the summer so it has little insulating value. It is good idea to double pot, by placing a pot with better insulating value, inside metal one. Generally they are not suitable for perennials, trees or shrubs because they are too hot in summer and too cold in winter.
Fiberglass Containers
Fiberglass containers are counterfeits of the container world. They are made of fiberglass but it’s really difficult to tell. Manufacturers have done a great job molding fiberglass to replicate concrete, stone and terra cotta. Their duplicity is revealed when they are picked up as they are lightweight. Fiberglass planters are strong, long lasting, and durable with good insulating value. Prices vary and some are better made than others so go by price as you get what you pay for. Since they are light, they are may fall over in windy locations.
Polystyrene Foam
Similar to fibreglass, polystyrene foam is often used to imitate other materials such as terra cotta. They are sturdy, long lasting, and lightweight. The sides and bottom are usually quite thick so roots are well insulated, however, look for ones with large drainage holes to allow water to drain freely. Even though these types of pots are quite common, they are also quite pricey.
Fiberglass containers are counterfeits of the container world. They are made of fiberglass but it’s really difficult to tell. Manufacturers have done a great job molding fiberglass to replicate concrete, stone and terra cotta. Their duplicity is revealed when they are picked up as they are lightweight. Fiberglass planters are strong, long lasting, and durable with good insulating value. Prices vary and some are better made than others so go by price as you get what you pay for. Since they are light, they are may fall over in windy locations.
Polystyrene Foam
Similar to fibreglass, polystyrene foam is often used to imitate other materials such as terra cotta. They are sturdy, long lasting, and lightweight. The sides and bottom are usually quite thick so roots are well insulated, however, look for ones with large drainage holes to allow water to drain freely. Even though these types of pots are quite common, they are also quite pricey.
Concrete & hypertufa pots are great for alpine plants. UBC
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Concrete
Well-made concrete planters have longevity and have an old world feel, especially if they are aged. They come in many styles and shapes depending on the mold used to cast the concrete. Give concrete containers a permanent location as they are very heavy, but at least they don’t fall over. New concrete planters leach lime, which makes the soil more alkaline. Allow them to weather outside for at least 6 months before planting. Since many alpine plants prefer a sweeter soil, they are good candidates for growing in concrete containers. |
Self-Watering Pots
Self-watering pots are a life-saver for those living in hot climates, for those that forget to water and when going away on vacation. They are so named as they have reservoir at the bottom of the pot that holds water. Some also have a wick that absorbs the water from the reservoir making it more available to the roots. To add water, just pour it in a conveniently located hole near the bottom of the pot. Self-watering pots are usually made of durable plastic and are more expensive than regular plastic pots. They are suitable for annuals (bedding plants) but not for perennials, trees, shrubs as roots grow into the reservoir promoting root rot and make it difficult to remove the plant to repot.
Self-watering pots are a life-saver for those living in hot climates, for those that forget to water and when going away on vacation. They are so named as they have reservoir at the bottom of the pot that holds water. Some also have a wick that absorbs the water from the reservoir making it more available to the roots. To add water, just pour it in a conveniently located hole near the bottom of the pot. Self-watering pots are usually made of durable plastic and are more expensive than regular plastic pots. They are suitable for annuals (bedding plants) but not for perennials, trees, shrubs as roots grow into the reservoir promoting root rot and make it difficult to remove the plant to repot.
This pot has a reservoir, just add water to the hole.
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This long planter works well for veggies as it has a reservoir below.
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Hanging Planters
There are many types of hanging planters from inexpensive wire baskets lined with sphagnum moss or coir fibre (coconut) to ones made of plastic with a connected drainage tray. Plastic coated wire baskets are more durable and more rustproof than non-coated types. They are suitable for bedding plants because there’s not much room for root growth. The trouble with wire baskets is they dry out quickly. To help retain moisturer, line the moss with plastic with a few holes poked in before adding the soil. If a basket becomes too dry (it happens), submerge the entire basket in water. Allow it to bubble, and once the bubbling stops, you can rehang it.
Locate hanging baskets so you can water them easily. Keep them out of hot afternoon sun and wind, as they will dry out too fast. It’s a good idea to place them where they can leak their excess water into a garden or other planter below. When it’s hot and sunny, they often need watering couple of times a day. Wire moss hanging baskets are high maintenance due to the challenging water schedule so I prefer plastic self-watering hanging pots. Yes they do exist although they are not as attractive as mossy baskets. Plastic hanging basket are very easy to find, are inexpensive and come in many colours. Look for ones with large drainage trays to catch and hold water.
There are many types of hanging planters from inexpensive wire baskets lined with sphagnum moss or coir fibre (coconut) to ones made of plastic with a connected drainage tray. Plastic coated wire baskets are more durable and more rustproof than non-coated types. They are suitable for bedding plants because there’s not much room for root growth. The trouble with wire baskets is they dry out quickly. To help retain moisturer, line the moss with plastic with a few holes poked in before adding the soil. If a basket becomes too dry (it happens), submerge the entire basket in water. Allow it to bubble, and once the bubbling stops, you can rehang it.
Locate hanging baskets so you can water them easily. Keep them out of hot afternoon sun and wind, as they will dry out too fast. It’s a good idea to place them where they can leak their excess water into a garden or other planter below. When it’s hot and sunny, they often need watering couple of times a day. Wire moss hanging baskets are high maintenance due to the challenging water schedule so I prefer plastic self-watering hanging pots. Yes they do exist although they are not as attractive as mossy baskets. Plastic hanging basket are very easy to find, are inexpensive and come in many colours. Look for ones with large drainage trays to catch and hold water.
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