The Hanging Gardens of Babylon and many of the exotic garden displays in Egypt, Greece and Rome often grew in containers of many shapes and sizes.
Today Container Gardening is among the most popular and often most practical forms of gardening. Almost everyone has a few treasured pots. Even confirmed non-gardeners will often proudly display some captive shred they have successfully kept alive. It is politically correct to be “green” these days. And those who can proudly display their well-kept collection of container-grown plants, even when grown in an urban high-rise apartment in the midst of a concrete jungle often receive accolades of appreciation for their ‘green fingers’.
A recent United Nations survey recorded that 97% of the world’s population is now removed from the land that supports them. Since Humankind are one of nature’s hunting/gathering species, it is not surprising that we instinctually reaffirm our earthy heritage through container gardening. And those who do this consistently, and really well, have indeed mastered a magic of environmental understanding that sets them apart from the rest.
Amongst the oldest and most sophisticated forms of container gardening would have to be the Bonsai.
The oldest Bonsai surviving today date back to the 17th century. One of the oldest-known living Bonsai trees, considered to be one of the National Treasures of Japan
, is retained in the Tokyo Imperial Palace
Botanical and Bonsai collection. This is a five-needle pine (Pinus pentaphylla var. negishi
) known as Sandai-Shogun-No Matsu. This remarkable Bonsai tree is considered to be at least 500 years old. Its history as an already favorite mature Bonsai specimen was recorded as being trained by Tokugawa Lemitsu
around the year 1610. Not far behind are the remarkable Sargent Junipers retained in the profound collections of Bonsai Omiya Village
. The first known records of a ‘Japanese dwarf potted tree’ recorded in the West date back to about 1692 but may date back to the late 1500’s.
Such remarkable artistic treasures as these most ancient Bonsai represent the consistent and reliable care of another living thing by upwards of 14 consecutive generations of reliable Gardeners, who would have provided some daily attention over approximately 182,500 days. Never failing to honour and uphold their responsibilities to care and provide for their upkeep. This is indeed a remarkable Human achievement, and the results show the magic and majesty
of this union between Gardener and Nature.
On the modern mundane but often equally attractive and very pleasurable side, is the phenomenon of decorative container gardening. Fuelled by those ancient hunting and gather instincts, Gardeners hunt for just the right plant and pot to match; gathering together suitable potting soil mix, drainage materials and fertiliser. Then put the pieces together in a ritual botanical feast of beauty that reflects our love and appreciation of Nature.
Container gardening is adaptable to modern life with something for everyone. Children still discover the wonders of Nature through seedlings raised in a paper cup. Indoor container plants help freshen our air and soften architectural lines; they can add a bright splash of colour to the balcony, deck, front door or veranda.
Botanical gardens feature dramatic displays of container plants in conservatories and shade houses. Roof gardens complete with climbers, flowers, hedges, shrubs, trees, topiaries and vegetables crown urban buildings. Hanging baskets, window box gardens or a tiny potted plant can adorn the smallest space.
No matter what the location, shape or size there is probably a plant for the spot. Almost anything can be successfully grown in a container. Some species adapt better than others. The larger the plant species and the more extensive its root system, the more difficult it can be to grow successfully in a container; at least for very long. Often larger and spreading species have big root systems that require very large containers. But some quite large species can sometimes be dwarfed through careful pruning of roots and top growth.
Proper placement is a critical factor. It is always important to research a plants’ native habitat and attempt to recreate that natural habitat if the plant is to be successfully grown in a container. Often it is easier to determine the parameters of the microclimate where the plant is meant to grow and then research and select plants that naturally grow in those sorts of positions. This will include: dry or wet; arid or humid; partial shade, shade or sun; still air or windy; cold, hot or temperate climate, etc. Many good garden reference books and internet sites have lists of plants that grow in specific climates: shade; sun; coastal; dry; wet, etc. Choosing the ‘right’ plant to match its’ ideal microclimate will make growing it much easier and improve its health, thus its ultimate success.
Here are a few examples of choosing plants that suit the microclimate in which they will most successfully grow: Aucuba japonica, temperate climate Ferns and Nandina will grow in light shade to soft sunshine where conditions remain moderately moist and temperate. Many species of Ferns, Philodendron, Pothos, and Spathiphyllum will tolerate (sub) tropical and warm shaded or lightly sunny positions in the garden that remain moist and frost-free. This also makes them ideal indoor plants. Azalea, Camellia, Daphne, Rhododendrons, especially Vireya; some Palm species; plus a variety of Annuals and Perennials thrive in partly shaded sites that remain evenly moist, with moderate temperatures and little if any freezing. Sun-loving container plants ideal for drier and very bright locations would include: Cacti and Succulents, most Herbs, a variety of hardy Annuals, Groundcovers and Perennials plus most Vegetables.
Drafty locations and extremes should be avoided as a general rule. Sites that become or remain excessively chilling, cold and drafty; deeply shaded; or very dry, sunny and scalding hot will each produce stressful conditions that can make long-term container growing more challenging. This is does not mean that it is unwise to grow container plantings in such locations as an exposed roof garden, just that extra care and precautions will probably be required to grow them there.
Container plants exposed to hot or very warm and possibly windy conditions should almost always include a saucer beneath the pot which will provide extra supplemental water. An automatic drip irrigation system might be considered for the more extreme situations, especially if there is the possibility that regular, if not daily watering can be provided.
Wherever plants could potentially be exposed to sustained chilling drafts or possible freezing, it is often a wise idea to double pot cold-sensitive container specimens. This involves potting the plant in the usual way, but then placing it inside a larger container. Then fill the space between the container plant and the larger pot with an insulating material like coconut fibre, dry compost, granulated bark, old potting mix, peat, perlite, sphagnum moss, etc. This will provided significant extra insulation to protect the container plant’s root system during chilling weather and cold nights.
While container plants are traditionally viewed as plants potted in ceramic, plastic, terracotta or wooded containers, there are also more adventurous options. These might include: a variety of hanging containers from baskets, to planter bags and cylinders to hanging wall gardens; very large raised planter beds and boxes; planted rooftops; terrariums of all sizes and many more creative adaptations.
Terra cotta and unglazed ceramic containers are ideal for plants that need a significant amount of air, somewhat drier over conditions and excellent drainage around their roots. Cacti, Succulents, Pelargonium (Fish, Scented Geraniums) many bulbs, especially epiphytic and subtropical bulbs like Hippeastrum (Amaryllis) thrive in terra cotta and often in concrete containers.
Glazed ceramic and plastic containers and non-porous pots are best suited to plant species that prefer fertile and moist soils that never completely dry out. Many favourite garden Annuals, Perennials, Shrubs, Trees and Vines perform better and for much longer when planted in this sort of container that doesn’t ‘breath’ as much as terracotta and remains much more water-retentive.
Drainage is critically important for most container plants. Good drainage is usually achieved by ensuring that each container has at least several drainage holes large enough to allow excess water to drain away rather quickly. Containers with a single drainage hole or even numerous very small drainage holes can become easily clogged as roots penetrate and block the holes. Soon water begins to collect around the roots which can eventually result in root rot or sour soil which can kill the plant.
To further improve drainage and adequate air flow, add a 1-2in/2.5-5cm layer of course drainage material to the bottom of each container. This could be broken brick, or crushed terracotta pots, granulated bark, pumice, river gravel, small stones, etc. This course drainage material will help protect the drainage holes from becoming blocked by plant roots and will facilitate an easy flow of both air and water to the plant roots.
The exception here are water plants like: Cypress Grass, Papyrus, Water Lilies and assorted water plants. These should be placed in a water-tight container such as a well-glazed ceramic or plastic pot. Generally avoid terracotta unless it is well-glazed. Being baked clay, terracotta readily absorbs water that can eventually start to bleed or sweat out of the pot and collect beneath it. This not only drains the water from the container but also can soak wooden surfaces or ruin decking or carpet beneath the container.
As a general rule, choose a container which is wider at the top than the circumference of the pot and with curved, rounded or straight sides as opposed to angled, cornered or indented containers. Many decorative containers such as olive jars and some dragon pots, Art Deco containers and other fine art containers are extremely decorative and appealing to use as plant containers. But it often proves very difficult to successfully plant directly into them. Once the plant(s) become established, their root system will become so cramped and dense that it will tightly fill every corner of the container creating a solid root mass. This root ball will be nearly impossible to remove from its container without significant root damage when time comes for transplanting and refreshing their soil. Instead, plant into a slightly smaller, perhaps less decorative, plastic bag or container that can be easily slipped down inside the larger decorative pot. This will make maintenance and transplanting much easier and save the decorative container from damage.
Growing in ground-connected containers, raised beds and seedling flats is another transitional approach to container growing. In this method, the container is directly connected to the soil beneath through large drainage holes. In raised beds, the entire bottom of the container could be connected directly to the soil beneath it. This option gives the plants’ roots the option to grow through the container and attach and feed in the enriched and moistened soil beneath the container. The drainage is vastly improved which is highly beneficial to many plant species. And the soil temperature in such containers becomes warmer in Summer but colder in Winter. Plants that demand extra water than can be provided in an enclosed container often can be grown much more successfully if they can spread their roots into the moist soil beneath their growing container.
For those who are handicapped or unable to bend and dig, such containers allow the option of growing in a raised environment that is more easily accessible. Where soils are excessively wet or potentially polluted, raised container gardens and beds keep the plants roots out of harm’s way.
Where it is impossible to dig a garden bed either because of lack of space, poor soil, debilitated health, lack of time, etc. most vegetables and many varieties of flowers and bulbs can be grown in boxes or seedling flats which are placed directly over roughened and slightly enriched soil. Seed or seedlings are sown or started in enriched potting mix in the boxes or flats just as if they were grown in the garden, only slightly closer together. As the plants grow, their roots are allowed to penetrate through the drainage holes and anchor into the enriched soil beneath. While the flowers and vegetable plants may be somewhat reduced in size as they mature, they will usually still produce excellent crops. Once the crops are harvested or flowers spent, the containers can be lifted, plants removed and composted then another crop started to replace what has been removed. In the case of bulbs, the boxes or flats can be removed and stored in a dry state for their required period of dormancy, then started again just as if they had been grown in the garden.
Here are more things to consider: