How to grow tomatoes
Nothing beats the taste of your own home-grown tomatoes, freshly picked and warm from the summer sun. Slice them into a summer salad, use as pizza toppings or add some depth to a curry, chilli or spaghetti bolognese. Whether you're growing them in greenhouses, pots or hanging baskets, our guide tells you all you need to know about growing tomatoes.
Tomatoes are undoubtedly one of the most satisfying home grown veggies (or fruits) and provide ample reward for effort. In fact, they have the highest yield for the amount of space they occupy, mainly because they grow up!
Growing tomatoes from seedlings or grafted plants is the easiest way to get started. Look for:
- Strong tomato seedlings with healthy foliage.
- F1 (first generation hybrids) and grafted tomatoes that have superior disease resistance. This information will be clearly printed on the label
- Tomato varieties that will give you what want choosing right tomatoes
If you like smaller salad tomatoes, try growing cherry or grape tomatoes. If you want to make passata, look for larger growing tomatoes like ‘Beefsteak’ or ‘Mortgage Lifter’ while for sauces and chutneys, try ‘Roma’. If you’ve got plenty of space in the vegetable patch and want big and juicy tomatoes, try ‘Big Boy’ or ‘Beefsteak’.
The type of tomatoes you grow may also depend on how much space you have. For example, if space is limited, try planting cherry tomatoes as they are perfect to grow in pots. If you have plenty of room in your backyard, grow big juicy tomatoes such as ‘Big Boy’, Beefsteak’, ‘Black Krum’ or ‘Brandywine’.
Where to grow tomatoes
In cooler areas, the tomato season can be extended by growing tomatoes in greenhouses until the weather is warm enough to start planting seedlings outdoors.
Tomatoes are very versatile. They can be planted directly in the open ground in a rich, fertile, well-drained soil or grown in pots filled with superior quality vegetable and herb potting mix.
Equipment list for growing tomatoes
To grow tomatoes at home, you will need:
- 9-10cm pots for sowing seeds
- 25-30cm diameter pots (if growing tomatoes on in pots until harvest)
- All Purpose Liquid Concentrate plant food Liquid Concentrate plant food
- Controlled or slow release tomato and vegetable fertiliser
- Superior quality vegetable and herb potting mix
- Stakes and ties
How to grow tomatoes from seed
There are dozens of tomato varieties available in seed packs from regular and mail order retailers. Some are modern types while others are ‘heirloom’ or old-fashioned varieties that have been around for generations. There’s an almost endless array to choose from but ultimately what you choose comes down to personal taste and perhaps recommendations from family or friends.
Tomato seed is best sown into individual peat pots (Jiffy Pots), seed trays or egg cartons filled with seed raising mix in early spring, when the soil in the vegie garden is still too cold to promote good germination. The seed containers should be placed in a warm, sheltered spot indoors but not in direct sun through a window. Keep moist but not wet.
When the seedlings are about 5-8cm high and have their first set of true tomato leaves (not seed leaves), thin them out to give them room to develop, transplanting the ‘thinnings’ into another seed tray.
As the weather warms and the seedlings grow, gradually harden them off by placing the trays outside during the day but bringing them in at night for protection. By mid to late spring, they should be tough enough to be outside all the time and ready to transplant into the garden.
Don’t be tempted to plant them out too soon though. One or two very cold nights could really set them back. Wait until day time temperatures are in the mid-20s and the possibility of night-time frost has passed.
How to plant tomatoes outdoors
To prepare for planting, break up the soil by digging it over and improve its texture and fertility by mixing soil improver and fertiliser into the soil. Water the tomato seedlings prior to planting. Choose a spot that receives at least six hours of sunlight per day, preferably protected from the wind.
You will need:
- A shovel
- Tomato hoop or stake
- Tomato seedlings or grafted plants
- Make a hole in the prepared garden bed large enough for the tomato seedling and its complete root ball.
- Carefully tap the tomato seedling out of the pot or gently lift it from the seed tray, trying to keep as much of the seed raising mix around the seedling's roots as possible. Carefully place the plant in the hole, making sure it is planted at the same depth as it was previously.
- Backfill around the tomato seedling, pressing the soil down firmly to hold it in place
- Insert a stake or tomato hoop, ready for tomato training. Water tomato plants well
- Apply snail and slug pellets to protect the young tender tomato seedlings
NOTE: Tomatoes should be spaced at 50-60cm intervals, to give them room to grow. Do not overcrowd.
Here’s a few extra tips for tasty home-grown tomatoes:
- Water plants regularly. Consider installing an automatic irrigation system. If this is not an option, water in the morning and try to avoid wetting the foliage.
- Apply a liquid fertiliser to seedlings to improve their frost tolerance while young.
Tomato plant care
Tomato plants require regular watering and feeding to produce healthy fruits. When watering tomato plants, the soil should be kept moist enough for moisture to reach the roots. Refrain from overwatering as too much water can deprive the roots of oxygen.
Feeding young tomato plants requires care as it is quite easy to overfeed and damage their sensitive roots. Young tomato plants should be fed as soon as they are transplanted using half the recommended application rate or dilution ratio indicated on the package. If a tomato fertiliser was added to the soil before planting, further feeding may not be needed until plants begin to fruit.
As plants grow, tie the main stems to stakes for support and remove the small side shoots that appear in the angles between side stems and the main stem. Once five trusses (side stems bearing leaves and fruit) have developed, pinch off the growing tip at the top of the main stem. This will focus the plant's energy on producing more fruit.
For smaller bush types, there's no need to remove side shoots or pinch out growing tips. However, you may need to support heavily-laden branches with stakes.
When to harvest tomatoes
Tomatoes should be harvested when the fruit is ripe and fully coloured. Here are some tips to help you identify ripe tomatoes.
Check the tomato seed packet or plant tag as this will provide information on the colour and hue of a ripe tomato.
Ripe tomatoes has a distinctly fresh aroma that can easily be identified.
Gently squeeze the tomato - ripe tomatoes will feel slightly soft.
As temperatures drop in autumn, tomatoes will eventually stop ripening on the plants. However, you can still ripen them indoors. Cut off all remaining tomatoes and place them indoors in a paper bag together with a banana or an apple. These fruits give off a gas called ethylene which encourages the tomatoes to ripen. The process takes about two weeks. Check the bag periodically and remove tomatoes as they ripen. Those that don’t ripen can always be used to make green tomato pickles!
Common tomato plant problems, pests and diseases
Tomato plants can be susceptible to pests and diseases so it is essential to ensure that these problems are prevented from the start.
One of the common problems is blight which can be in two forms. Early blight occurs due to a fungus which flourishes in wet conditions. It is visible as concentric spots on plant leaves and can weaken the tomato plant. Late blight shows up as grey, greasy spots on leaves, stems and fruit. They can pose as a potential threat to your garden.
|Blossom end rot||
Blossom end rot is caused by lack of calcium in the fruit. A circular patch varying in size and colour (from brown to black) at the bottom of tomato fruits is the classic symptom of blossom end rot.
Other diseases include powdery mildew, verticillium wilt and fusarium wilt.
Whitefly live on the underside of the tomato leaves and weaken the plant by sucking the sap of plants.
Pests such as the tomato fruitworm, aphids, hornworms and cutworms can destroy your tomato plants so treat them with a naturally based insecticide spray that is safe to use on edible plants if they are present.
For more information on pests and diseases download our free guide.