How to choose containers for growing vegetables
March 31, 2017
Choosing the most suitable container or pot to grow your vegetables and herbs will influence their growth, particularly if you live in a tropical region of Australia. Materials have varying levels of water and heat retention properties.
I have said on many occasions that you can grow fresh food in any available container, this is true. Be aware of the properties of readily available options and take them into account when you plant in them – for example, you may need to water more often, line the container, mulch or position the container in semi-shade.
Ensure all containers have drainage holes. If the container is large, it will benefit from being elevated off the ground with “feet” to maintain the drainage. You can use blocks of wood for this purpose.
In the warm months of the year use straw to mulch around the top of the plants and help retain moisture and keep the soil temperature as low as possible.
Consider the following when selecting the pot you will use to grow herbs or vegetables:
The ideal size of pots for growing vegetables and herbs is a minimum depth of 250 mm. Larger vegetables, small trees and heavy feeding plants require much deeper containers.
Miniature fruit trees require a pot depth of at least 600 mm. Fruit trees do not like to compete with the roots of other plants so if you are considering using a large container for a fruit tree, it should only be under-planted with shallow rooted plants that will not impact the growth of the tree. This includes plants such as lettuce, asian greens, and herbs
Ensure you consider the size the plant will grow to, not the size it is when it is planted.
Untreated timber is the preferred choice for any containers made from wood. It is a low cost, rustic looking organic material. Wood is porous and requires regular monitoring to ensure moisture is maintained. The box shown above has been lined with coconut fiber to prolong the life of the wood and to enhance water absorption.
Untreated timber will degrade over a period of time, 5-15 years depending on the type of wood used. This may be extended by lining the container with a fiber as above, a food grade material or by using an organic sealant such as linseed oil or beeswax.
Wine barrels provide a good option for planting small trees and herbs. They are designed to remain wet. If they dry out they are said to be prone to splitting. They may also be attractive to termites if these are a problem in your area.
Large wooden raised beds provide a larger container option. They allow the soil to be well maintained and are positioned at a convenient height for children and adults alike with a planting space suitable for growing a steady supplier of meal ingredients for a family. I provide a complete delivery, installation, seasonal planting and 12 month coaching support package of untreated timber crate beds (shown below). These crates are lined with food grade material and straw for soil nutrition and prolonged life of the wood. Book a free site visit and find further information and a brochure about my service here.
Readily available and in a wide variety of styles that can be suited to your home decor. Terracotta allows the soil to dry out quickly due to it’s porous nature. These pots require regular monitoring and watering. The material will degrade over a period of time, absorbing salts and showing irregular patterning. Avoid terracotta if you are seeking a pristine, uniform look.
Glazed Terracotta provides a longer life and will dry out a little slower. Over time these pots tend to show cracking in the glaze so as per above, if you are seeking a pristine uniform look this may not be suited long term.
Containers that are metal will heat up fast when exposed to heat. They are cheap and readily available with a rustic appeal.
Metal containers will rust after a period of time and may also have sharp edges to monitor if you are gardening with children.
Concrete maintains moisture well. They may crack over a period of time and are so heavy they are unsuited to use of a balcony, or if you wish to move your containers around. If you live in a rural area you may be able to collect an old trough from a farm sale or community market.
Low cost and easy to access. Plastic pots are durable and will not degrade. They are lightweight and will hold moisture well. This one in the image above is a wicking-bed. You can read my review of this particular product here.
You may be able to collect these from a fruit market of grocery store and they have great water retention properties. They are cheap, or free and are light weight and portable. Look out for snails hiding around the drainage holes if you are using these.
I have herbs and vegetables growing in a wide variety of containers including a wheelbarrow, a biscuit tin, olive oil tins, an old wash tub, an old mop bucket. If you follow the tips below you can grow in any container if you take the time to understand the properties of it and ensure you provide your plants and soil with the relevant care.
Growing in containers in convenient. It provides additional growing space if you already have a garden. They provide the opportunity to grow some fresh food in a small space.
The soil in containers will deplete quickly and should be maintained and changed on a regular basis. Use high quality registered organic input soil. The better the quality of soil you use, the greater success you will have growing.
If you are time poor and beginning to grow fresh food for the first time in containers be aware that they do require regular monitoring for water, especially in summer.
Not all plants are suited to growing in containers. Those that grow to a significant size are better suited to growing in the ground. Some plants are also very slow growing. I suggest that growing something like onions in a container (they take up to 4 months to grow) is not a great use of the available space. Select vegetables or herbs that are small and fast growing. Read the planting instructions and allow adequate room for plant development when spacing plants together in a pot.
You may also like to read this post on small space container growing that I wrote last year.
Are you using an alternate type of container I have not mentioned? What is it and what is your one tip for success?
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