Growing tomatoes: A Guide to Growing Tomato from Seed

Tomatoes are a favourite in the Australian home garden for many reasons. They are versatile, nutritious, and easy to grow, even from seed. Whether you are a seasoned gardener or new to the game, starting your tomato plants from seed can be a fun and rewarding experience. It allows you to choose from a wider variety of plants and gain full control over the growth process. However, for new gardeners, starting from seed can seem daunting. But don't worry, we've got you covered! In this guide, we will share tips and tricks on how to grow tomatoes from seed so you can have a bountiful harvest all summer long.

Choose Your Tomato Variety

First up, choose which variety of tomato you want to plant. There are hundreds of different types of tomatoes, ranging from small cherry and grape varieties to large beefsteak varieties. Consider factors such as taste, size, and disease resistance when selecting your seed.

There are two types of tomatoes: climbing or vine, also known as 'indeterminate', and bush, also known as 'determinate'.
Climbing or vine tomatoes require staking and keep growing throughout the season and produce tomatoes that ripen at different times. Staking ensures the vines don't become too heavy and collapse under the weight of the fruit. You can use wooden or metal stakes and tie the vines to them using twine or wire. We find these are the most popular tomato types.
Bush tomatoes grow into a bush and have a single flush of fruit that ripens together. For bush tomatoes, you don't need to worry as much about staking, but you still need to space them correctly to prevent overcrowding.

When choosing which type of tomato to plant, consider the size of your garden and time commitment. Climbing tomatoes require more maintenance, such as pruning and staking, while bush tomatoes are more compact and don't need as much attention.

Sowing your seeds

Before planting tomato seeds, make sure you have prepared the right environment for them. Start with a good quality seed raising mix that is well-draining and contains plenty of organic matter. Use a clean container that is at least 5 centimetres deep and has drainage holes at the bottom. Tomatoes thrive in warm soil, so keep the temperature between 18-25°c. We use a seedling heat mat with a thermostat to ensure the soil is kept at an optimum temperature.
Once the seedling mix is ready, it's time to plant the seeds. You can start tomato seeds indoors six to eight weeks before the last frost date in your area. Sow them 5mm deep and cover with a thin layer of soil or vermiculite. Water the soil gently and keep it moist but not soggy. Place it in a warm and bright spot, you can even cover them with a plastic dome to keep the warmth and moisture in. Be patient as it can take up to two weeks for the seeds to germinate, however at a warm temperature 18-25°c you can expect to see them up within a week.

Caring for tomato seedlings

Once the seedlings emerge, remove the plastic lid and make sure they have plenty of light. If you are growing them indoors, use grow lights or place them in a sunny spot that receives at least six hours of sunlight a day. Water the seedlings frequently but avoid overwatering, as this can cause dampening off disease. Fertilize the plants once a week with a balanced fertilizer to promote healthy growth. When the seedlings have at least their second set of true leaves and are 10 to 15cm, it's time to transplant them outdoors in the garden or, if there is still the risk of frost, pot them up into individual pots until the risk of frost has passed. Use a larger container and bury the stem up to the first set of leaves to promote a strong root system.
Before planting, harden off the seedlings by gradually exposing them to outdoor conditions, starting with a few hours a day and gradually increasing the time over a week. This way, when they are planted into the ground they will only have the shock of being transplanted, rather than the change of temperature/weather conditions and transplant.

Transplanting tomato seedlings outdoors

Tomatoes, like most summer vegetables and flowers, need a spot in the garden that has at least six to eight hours of direct sun light. Prepare your soil with fertiliser, a layer of approximately 10cm of compost, and of course access to water. Plant the seedlings deep and water them thoroughly. Add a layer of mulch to keep the soil moist and prevent weed growth. Support the plants with stakes or cages to keep them upright as they grow.

Maintenance and Harvest

Tomatoes require regular maintenance to stay healthy and produce a bountiful harvest. Water them regularly, especially during dry spells, and fertilize them every two weeks with a high-potassium fertilizer to promote fruit formation. Prune the plants to remove suckers and lower leaves that touch the soil to improve air circulation and prevent diseases. As the fruits ripen, pick them regularly to encourage new growth. When the season ends, harvest any remaining green tomatoes and use them for frying, pickling, or ripening indoors.

Growing tomatoes from seed is a rewarding experience that allows you to enjoy a variety of flavourful and nutritious fruits. With the right preparation, care, and environment, anyone can start their tomato plants from scratch. So, roll up your sleeves, get your gardening gloves on, and start your tomato seedlings today. With a little patience and practice, you can have a thriving crop of juicy tomatoes in your backyard all summer long.
Happy gardening!