How to successfully grow tomatoes in containers
November 9, 2018
If you have a small space, or are short on growing space in your vegetable garden, containers can be used to success fully grow tomatoes.
The questions below will help you achieve success when planting your containers.
The container size is important to ensure there is enough space for the roots to develop and to allow the plant enough soil to deliver nutrient requirements for strong growth. The larger the size, the easier it is to maintain moisture levels also.
The larger the size of the container you use to plant the tomatoes the better. At a minimum select a container that is at least 35 cm in diameter. The best size would be larger than this, the diameter of a half barrel, this would allow you to under-plant basil or other herbs if you wish. The containers should also be at a minimum 30 cm deep, again deep than this is better.
Consider the variety of tomato you choose to grow in a container. Many varieties grow very tall and require support.
I select plants that produce cherry sized tomatoes. They are prolific producers and the plants are usually smaller and require less staking.
Tomatoes referred to as “determinate” are bush varieties and are more compact in size than “indeterminate” tomatoes that can grow to six foot tall (or more) and require support as they grow. Read more information on varieties I prefer to plant in the linked articles at the end of this page.
The soil you select will heavily influence the harvests you receive and the health of your plants. Add fresh soil to containers prior to planting, avoid replanting in containers that have grown something else previously. Select a soil that is labeled with the Australian Organic Registered Product green bud logo if possible. Alternatively select a soil that is labelled as suitable for growing vegetables. Add a few handfuls of compost, some worm castings, and crushed egg shells to the soil and mix it through the top layer. On a regular basis (monthly) water with Eco seaweed or worm juice. The crushed egg shells provide calcium to the soil, save them from the kitchen and regularly add them to the containers, or garden. To apply egg shells ensure they are dried and crushed prior to adding to the soil. Suitable amounts of calcium in the soil of tomato plants are said to help prevent blossom end rot in plants. See this post on growing tomatoes for more care information.
Tomatoes require full sun of at least 6 hours per day.
Be aware that tomatoes grown in pots require watering more often than those grow in a garden bed. They dry out quickly in containers and as a result the care requirement is a little higher. On high heat days you may need to water once, or even twice a day. Avoid allowing the soil to dry out. When watering, ensure it is always done at the base of the plant, not over the top of the leaves.
Position the container away from solid surfaces that reflect heat, such as a brick wall or iron fence. The exception to this is when the placement of the containers does not allow for more than 4 hours of sun per day. If this is the case, a wall may assist growth of the plant by continuing to radiate heat once the sun is no longer on the plants.
Add a layer of mulch to the top of the soil in the container once the plant becomes established. This will help to reduce moisture loss from the soil.
Remove laterals if you prefer to keep the plants compact. A lateral is a shoot of new growth that forms in the V shape between the stem of the plant and a branch. See the picture below. I remove these from plants to help keep them compact and neat. This practice is said to allow the plants energy to be directed too fruit production rather than leaf production. The primary reason I choose to do it is to create a semblance of order in an abundant summer garden.
Some people argue that determinate, or bush tomatoes should not have laterals removed. I have never bothered distinguishing or treating the different plant types differently. All of my plants have the laterals removed each year up until approximately mid January then nature takes over. This sometime lags or drops off completely once the plants are producing heavily but it is a focus for me at the start of the season, at least up until the plants are being regularly harvested.
Tomato plants can be provided with support from stakes or tomato cages, the choice is personal preference. They are not required at all if you plant a bush variety and are not worried about a naturally messy look in the garden. The plants will produce regardless of being staked or not. You may also use string to grow the plants vertically if you have a frame that can be utilised to support the string above the plants. Read more about that here.
Staking tomatoes grown in containers has the benefit of providing stability to the container. Place the stakes outside the container, or the frame over the top of the container. Place stakes behind the container of beside the container. Use soft ties to secure the plant to the stake. Wire ties will damage the stem of the plant as it grows.
As the fruit begins to develop add another couple of handfuls of compost to the soil.
Other tomato growing information you may find useful:
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