Growing plants in containers is trending upward in popularity each year.
It is recognised on so many levels, from a form of art which allows creativity in the planting combination and matching the pot to the other end of the spectrum where growing plants in containers is used to serve a function - for example, in an apartment where there is no garden available to grow plants. Containers are used in courtyards where there is no soil and the softening effect of live plants offers aesthetic appeal, as well as in large gardens where pots are used as focal points, indicate an entranceway to another garden room or a way to provide colour in the off season by way of the pot design.
Growing plants in containers presents gardeners with endless opportunities to express their imagination and flair. It is an interesting hobby and is suitable for properties of every size.
One of the best things about container-grown plants is that they can be moved about from one place to another, provided that they are not too heavy or awkward to handle. This way you can give plants a suitable microclimate to display and show them off when they are at their best.
Choices include a fragrant plant by the front door, a cheerful bowl of spring bulbs, an immaculate piece of topiary or why not grow something edible. You can grow almost any plant in a container, whether you would like to brighten up a shady area or just provide some cool green relief from the hot sun. It's just a matter of choosing suitable plants for the particular conditions. Once you have decided which particular look or style appeals the next question is what sort of pot or container?
There is a superb range available to choose from. Containers come in all shapes and sizes. They are made out of many different materials and prices vary dramatically, mostly depending upon the degree of difficulty with which they are created. Some of the types available are glazed earthenware (ceramic), terracotta, wooden containers or plastic pots.
There are many objects which have outgrown their original use and are ideal containers for growing plants. Old troughs, cooking pots, coppers, wheelbarrows, baths, beach driftwood and pumice are often used. Even old disused boots and gumboots are occasionally seen supporting herbs or other healthy plants. If providing drainage holes presents a problem, you can use a plastic pot inside the container, raised on a small amount of gravel or chip stone and keep a check that they don't get waterlogged.
Situation and soil
To grow plants successfully in containers you must select the right plant for your situation. If it is a windy spot, plants must be able to stand up to it. Sunlight and shade considerations are also important and will influence your choice of plants. Sun-loving plants, including vegetables, require at least four to five hours' sunshine each day to grow successfully so check the amount of sunshine before selecting plants that could turn out to be unsuitable. All containers must have good drainage otherwise your plants can become waterlogged. Most pots and tubs have one or several drainage holes 1cm-2cm in diameter. Ordinary garden soil is unsuitable for pots because it does not drain well and can set hard. Potting mixes available from garden centres are generally manufactured from pine bark and pumice and are open and porous. They are free of weed seed, soil pests and plant diseases. Always purchase a good quality potting mix to obtain the best results. In general, the more you pay for your potting mix the better the quality and the results will be.
From many trials I have done over the years I recommend Tui Pot Power or Natural Bark brand potting mix.
Gardening: Watering key to success of your summer garden
Succulents great for indoor or outdoor growing
When potting up most plants it is best not to put a small plant in a huge pot. Plants just may not thrive in over-large containers and some plants prefer to be crowded. It is best to move a plant into a slightly larger pot when the previous one is full of roots. When potting, leave a margin between the soil level and the rim of the container. When watering, fill this space slowly with water until it drains from the holes in the bottom of the container. A mulch of coarse metal (gravel), pebbles, bark chip or nuggets helps reduce evaporation and cools the surface soil.
Good drainage and frequent watering causes leaching of plant nutrient. Regular small amounts of fertiliser are needed to keep plants growing strongly. Always apply fertilisers to moist soil to avoid burning young roots. The water soluble or liquid fertilisers, such as Ican Fast Food, Thrive Liquid and Nitrosol, are suitable for regular liquid feeds. Slow acting fertilisers, such as Yates Acticote, Tui Enrich Slow Release or similar, are suitable to provide nutrients over a long period. Always use fertilisers following the manufacturer's instructions on the label. Too much fertiliser can have a burning effect on plants, especially if the potting mix dries out.
Vegetables in containers
• Premium - Gareth Carter: Prickles, moss, weeds - how to keep your lawn pristine this summer
• Premium - Gareth Carter: Growing your own avocados is rewarding
• Premium - Gareth Carter (Gardening): Lawns, vegetables, flowers and weeds - it's all to do this spring
• Premium - Gareth Carter: Love 'em or hate 'em, it's brussels sprouts planting time
It truly is amazing how much produce one can grow in containers. Most vegetables in containers will grow faster and have a shorter time to harvest than those grown in the garden. This is predominantly due to the higher soil temperature that a container will maintain as the sun shines on it and heats up the potting mix.
Herbs have long been grown in containers somewhere close to the kitchen where they can be quickly chopped and added to the evening meal. More recently many people are growing other vegetables in containers. Lettuces are an easy starting point with a time frame of four to six weeks to harvest of some of the fancy leaf varieties. You only need a couple of pots and a small family can have lettuce every week of the year.
During the summer months tomatoes, capsicum, chillies and dwarf beans can all be successfully grown in containers. At this time of year you can plant sugar snap peas up some bamboo stakes in containers, silverbeet (the rainbow coloured variety is an eye catcher in containers), spinach planted now can have leaves harvested when they are up to size and should continue to produce through until spring. Even broccoli, cauliflower and cabbage can be grown in a decent size trough. Smaller growing or "mini" varieties of these are available and are great for containers as they don't take up as much room and have a shorter time to maturity. The smaller size of the produce means these are great if you don't want to eat cabbage every day for a week.
Fruit in containers
Growing fruit trees in containers has become very popular for a few of reasons - it gives a planting option when the garden is already full, it can help contain the size of the plant and you can take it with you if you move.
There are a number of fruits that can be successfully grown in containers, including dwarf peaches which are grafted on stem heights varying from 50cm to 90cm and form a rounded topiary head. These beauties have magnificent spring blossoms and fruit prolifically from their first year.
Citrus can make excellent container plants and will fruit successfully. The secret of success for these is monthly fertilising along with daily watering during the summer months. Positioning the citrus in a warm sheltered location away from the prevailing wind is also important to ensure success.
Bush growing fruits such as blueberries, Chilean guava and cherry guava can all be successfully grown in containers.
* Gareth Carter is general manager of Springvale Garden Centre