How to Grow Tomatoes

Tomatoes are the most popular choice of homegrown produce and with many varieties available, there’s always something new to try for gardeners of all experience levels. In this guide, we’ll explain how to grow tomatoes in detailed steps and answer some frequently asked questions about growing tomatoes in Australia.

Tomato Classification

Family

Solanaceae.

Genus

Solanum lycopersicum.

Tomato Varieties

There are over 10,000 tomato varieties and the most popular include beefsteak tomatoes, vine tomatoes, cherry tomatoes, gardener’s delight, and globe tomatoes.

Cherry tomatoes are small, round fruits with a sweet flavour making them ideal for snacks, salads, and roasting. Standard tomatoes are larger, medium-sized fruits with a beautiful aroma and well-balanced acidic sweet flavour, also making them great for salads as well as sandwiches and sauces.

Beefsteak tomatoes are the largest tomato type and have a meaty flesh with a mellow flavour. This makes them best suited to burger slices, sandwiches, and cooking.

You can start your tomato seeds early by sowing them indoors in Jiffy® Pots or Pellets, available in our seed-raising range, or in seed-raising trays, from as early as July. A windowsill greenhouse kit will also provide a perfect seed-raising environment on a sunny windowsill.

Cover the seeds lightly with fine soil and water gently so they are not disturbed. To aid germination, keep the pots or trays at approx. 15-20°C by placing it on top of a HeatPad, and cover with polythene or a propagator lid to help keep the soil moist and warm. Remove the cover when seedlings appear.

Alternatively, tomato seeds can be sown directly into a garden bed or container, as soon as the risk of frost has passed and the soil is sufficiently warm day and night.

If your tomatoes are kept in their pots for some time before transplanting, feed them regularly with a balanced liquid vegetable feed - about every week or so. Tomatoes are hungry crops and will use the nutrition inside a small pot of soil quickly.

Transplant the seedlings into the garden when they are large enough to handle, and when danger of frost has passed – usually before the end of September, or later in cooler climates. Always hold seedlings by a leaf to avoid crushing the stem. If you have grown your tomatoes in Jiffy® pots or pellets, you can transplant the seedling with pot and all, thus avoiding transplantation shock. When transplanting you can plant your tomato seedlings quite deep, this will help your tomatoes to grow more roots both to stabilise themselves and to absorb more nutrients from the soil.

Before transplanting young plants, acclimatise them to outside conditions by placing them in a sheltered location for a few hours during the day, gradually increasing the time over two weeks. Once ‘’hardened off’’, plant them into their final growing position at the spacing indicated on the packet.

Your tomato side shoots need pinching out regularly to contain the plants. These appear between a leaf node and the main stem, just below the flower stem. Work through your plant every week or two during the height of the growing season to remove these side shoots, allowing around 2-3 main stems to grow and mature depending on the size of your frame or trellis. If using a single stake or string it is best to remove all of the side shoots so you only have a single branching plant.

• Mulch the ground around the plants once the soil has fully warmed up. This will help to conserve moisture and suppress weeds. Feed the plants every 4-6 weeks with organic slow-release fertiliser, such as pelletised poultry manure amended with trace elements. It is also helpful to apply a high-potassium liquid fertiliser and seaweed solution fortnightly when the flowers start to form fruit.
• Tall-growing indeterminate tomato varieties will need support, either with canes or string tied to an overhead A-frame. Bushy or determinate varieties can often sprawl onto the ground, but if you live in a humid or wet environment, these will also benefit from staking to allow more airflow in and around the plants to help prevent disease.
• Water plants regularly to prevent the skins from splitting. It is best to water at soil level, keeping the foliage of the plants dry to discourage mildew.
• If you are staking the plants, do it immediately after transplanting to minimise the risk of damaging new roots.
• Remove lower leaves as they discolour or die off to prevent disease. They are best put into the bin rather than composted.

How to Prune Tomato Plants

When your plant reaches the top of your stake or trellis remove the growing tip of the plant to bush out. If it grows too tall above the support it will slump over and break.

Alternatively, use the ‘’lower and lean’’ method, which is great for those trailing types. With this method, the string on your frame is lowered, allowing the new growth up top to reclimb the twine leaving a long stem along the ground. The bottom of the stem is removed from all old leaves to keep the crop healthy and allow plant growth to refocus into the fruits and new leaves.

Pest and Disease Prevention

Mixing tomato plants with French marigolds may help to deter pests such as whitefly. Other good companion planting options are basil, chives, onions, and nasturtiums.

Trailing indeterminate tomatoes may fruit for many months provided they are well fed and maintained. Determinate bushy tomatoes may set the majority of their fruits in just a few weeks.

To harvest your tomatoes, use a set of garden pruners or twist the fruit until it frees from the vine, and avoid pulling the fruit itself when picking as it can break the branches. Use any surplus fruit to make chutney or freeze as sauces, tomato juice, or as whole fruit.