There’s nothing more rewarding than picking fresh, homegrown tomatoes.
And surprisingly, they’re easy to grow. But there’s a caveat: you have to know exactly when to plant them.
The rule is to avoid growing tomatoes when it’s too hot, too cold, or too humid.
But once you’ve got the timing right, all they need is well-drained soil, lots of sun, and regular watering.
Here’s how to grow tomatoes in Australia and set yourself up for a big, juicy harvest!
When To Plant | Growing Conditions | Where to Grow | Steps to Plant Tomatoes | Care | Harvesting Tomatoes
All About Tomatoes
Botanically, tomatoes (Solanum lycopersicum) are classified as a fruit. They develop from flowers and contain seeds, which makes them berries.
But in the kitchen, we treat them as vegetables because of their savoury taste.
Tomatoes belong in the nightshade family, making them close relatives of capsicums, eggplants, and potatoes.
Tomato plant lifecycle
Tomato plants take about 2–3 months until they’re mature and ready to fruit.
They start from seed and go through these stages:
- Germination
- Leafy growth (vegetative)
- Flowering
- Fruit production
Tomato flowers are complete, with both male and female parts, which means they’re self-pollinating.
Wind and insects are usually enough to ensure pollination and fruit set.
In Australia’s colder regions, tomatoes are grown as annuals. They naturally decline after fruiting and have to be replanted for the next growing season.
But in warmer, frost-free climates, tomato plants can survive for a longer time.
Types of tomatoes
Before growing tomatoes, it’s helpful to understand the different types so you can choose the right ones for your garden.
Tomatoes are generally classified by how they grow and how they’re bred.
While all tomatoes are technically vines, their exact growth habit differs between types.
Determinate tomatoes grow to a fixed size (usually 0.5–1m). They produce fruit in one big flush before dying back.
Indeterminate tomatoes are often called “true vines.” They sprawl and fruit continuously throughout the season until the plant dies.
You’ll also find heirloom and hybrid tomatoes.
Heirloom tomatoes have been grown for over 50 years or more. They’re prized for their flavour and are naturally pollinated by wind or insects.
In contrast, hybrid tomatoes are bred by cross-pollinating two varieties. This is done to improve disease resistance, fruit quality, and yield.
Heirloom and hybrid tomatoes can either be determinate or indeterminate.
Popular tomato varieties in Australia
In Australia, some of the most popular tomato varieties are as follows:
DETERMINATE TOMATOES
- Tiny Tim: A dwarf cherry tomato variety
- Patio: Bred for containers and small spaces
- Roma: Popular for tomato sauces and pastes
INDETERMINATE TOMATOES
- Grosse Lisse: Large, round, classic red tomatoes
- Cherry: Small, sweet fruits, best for snacks and salads
- Green Zebra: Light green when ripe, good disease resistance
When to Plant Tomatoes in Australia
When growing tomatoes, timing is everything! The best time to plant tomatoes in Australia depends on your climate.
The general rule is to avoid growing tomatoes when it’s too cold (risk of frost), too hot, or too rainy.
In tropical and subtropical climates, you can grow tomatoes year-round, but they do best in the dry season.
In cooler climates, you can sow tomato seeds indoors to keep them warm as you wait for the weather to improve.
That way, you can transplant the seedlings as early as possible and maximise the shorter growing season.
To make things easier, here are the best months to sow seeds and transplant tomatoes:
| CLIMATE | WHEN TO SOW TOMATO SEEDS | WHEN TO TRANSPLANT SEEDLINGS | TOMATO GROWING SEASON |
|---|---|---|---|
| Tropical and Subtropical | Start of dry season (March–April) | Dry season (April–August) | Year-round |
| Cool and Cool Temperate | 6–8 weeks before the last expected frost | Spring (late September–November) | Mid-spring to summer (October–February) |
| Warm Temperate | 6–8 weeks before spring | Late winter to mid-spring (late August–October) | Mid-spring to autumn (October–May) |
Tomato Growing Conditions
To grow healthy and juicy tomatoes, give your plants the right growing conditions.
Tomatoes thrive in warm weather, full sun, and rich, well-drained soil.
If you need a hand to get your garden tomato-ready, book an experienced gardener to help with soil preparation and planting!
Climate
Tomatoes can thrive across much of Australia. They prefer warm, dry climates, ideally with temperatures between 15°C and 29°C.
Tropical and subtropical climates are suitable. Just keep in mind that heavy or prolonged rain can slow fruiting and increase the risk of disease.
That said, tomato plants can still grow in cold climates.
However, their growing season will be shorter since they’re frost-intolerant. Anything below 0°C can kill them!
Light
Tomatoes need 6–8 hours of full sun daily to grow strong and produce lots of fruit.
If temperatures regularly exceed 32°C, give tomatoes a bit of afternoon shade to protect them from getting scorched.
Soil
Tomatoes prefer rich, well-drained soil that’s slightly acidic to neutral (6.2–6.8 pH level).
They hate being waterlogged, so excellent drainage is crucial.
Before planting tomatoes, prepare the soil first, ideally 2-3 months ahead.
Check the soil pH with a test kit from your local garden centre. Follow the directions on the packaging for accurate results.
Also, enrich the soil with organic matter or well-rotted manure, as tomatoes are heavy feeders.
Do not plant tomatoes in the same soil where nightshades (like eggplants and potatoes) have grown in the past 2–3 years!
Practice crop rotation to prevent soil-borne diseases that affect these plants.
Where To Grow Tomatoes
Usually, you’d get the best harvest if you grow tomato plants in a garden bed outdoors.
But if you don’t have the space, growing tomatoes in pots or indoors is also possible.
Growing tomatoes in a garden bed
An outdoor garden bed gives tomatoes the space and sunlight they need to grow strong and produce plenty of fruit.
Choose a sunny spot with some afternoon shade. Make sure the area is protected from strong winds.
If you’re planting multiple seedlings, space them 75–100cm apart for good air circulation.
For heavy clay soil, consider building a raised tomato bed to improve drainage.
Growing tomatoes in pots
Planting tomatoes in pots is a great option if you’re short on space.
Plus, pots are easy to move, so you can easily protect your tomatoes from strong winds or intense sunlight when needed.
For best results, choose a determinate (bush-type) variety. They’re more compact and better suited to containers.
Use a good quality potting mix and a plastic container with drainage holes.
It should be about 30–40 cm wide and deep enough to bury half to two-thirds of the tomato’s main stem.
After planting, place the pot in a sunny area like a balcony, patio, or indoors.
Lastly, keep in mind that potted tomatoes need more frequent watering and feeding than those in the ground.
Growing tomatoes indoors
If you live in a cooler climate but want to grow tomatoes all year, you can do so indoors.
Just keep in mind that indoor tomatoes usually fruit less than those grown outside.
To mimic sunlight, use full-spectrum LED grow lights. Keep them on for 14–16 hours a day, followed by 8–10 hours of darkness.
Position the lights about 20–25cm above the plants, and adjust as the tomatoes grow.
Since there’s no wind or insects indoors, you’ll need to hand-pollinate the flowers.
Once flowers appear, gently tap each flower stem several times to help spread the pollen.
You can also use an electric toothbrush to imitate a bee’s buzz. Just touch it to the flower stem for a few seconds.
Repeat this a few times a day to ensure successful pollination.
How To Plant Tomatoes
You can successfully grow tomatoes from seeds, as they germinate quickly.
If you want to skip the extra work, you can also start from a store-bought tomato seedling!
Step 1: Sow tomato seeds
First, dampen your seed starter mix so that it feels like a wrung-out sponge.
Use a seed tray or small pots with drainage holes. Fill the container with the soil mix, leaving a little space below the rim.
Next, make shallow holes in the soil, about 0.5cm deep. Put 1–2 tomato seeds in, and cover lightly with soil.
Place the tray in a warm, bright area with indirect sunlight. Keep the soil temperature at around 21°C–24°C, which is ideal for germination.
Water regularly so the soil stays moist but not soaked. Tomato seeds usually germinate in 5–10 days.
If two seedlings appear, snip off the weaker sprout to let the stronger one grow.
Step 2: Harden off tomato seedlings
Before transplanting, harden off your tomato seedlings to help them adjust to outdoor conditions.
Start about a week before the last expected frost, or once nighttime temperatures are at least 15°C. Seedlings should also have at least 1–2 sets of true leaves.
Begin by moving the tomato seedlings to a shaded area outdoors that’s protected from wind.
Leave them there for 2–3 hours, preferably in the morning, then bring them back inside.
Gradually increase their time outdoors each day, and slowly introduce sun and breeze.
Do this over about 2 weeks. If your tomato plants show signs of stress (like yellowing leaves), give them a break indoors.
Once tomato seedlings can stay out all day and night with no issues, they’re ready to transplant.
Step 3: Transplant tomato seedlings
Transplant your tomato seedlings about 2–3 weeks after the last frost.
Gently remove each seedling from its container. Pinch off the lower leaves, but keep 3–4 healthy ones at the top.
Dig a hole slightly wider than the roots and deep enough to bury half to two-thirds of the stem.
Tomatoes can grow roots from any buried part of the stem, so this helps them develop a stronger root system.
Next, place the tomato seedling into the hole. Backfill with soil, and press gently.
Water thoroughly after planting, then mulch around the base using organic matter like straw or grass clippings.
Step 4: Support tomato seedlings
Tomato plants need support to stay upright as they grow.
This is especially true for indeterminate tomatoes, which sprawl continuously and generally have weaker stems.
However, even bushier determinate types need some help, since their stems might bend or snap once they start fruiting.
To avoid disturbing the roots, add support for young seedlings right after transplanting.
Here are a couple of ways to support tomato plants:
CAGING: Place a wire cage around the tomato seedling. As the plant grows, it’ll naturally climb up the wires.
STAKING: Push a sturdy stake 15–20cm into the soil, 5–10cm from the main stem. Gently bind the stem to the stake with a soft garden tie. Keep doing this as the plant grows.
Caring for Tomato Plants
To get the best harvest from your tomato plants, keep up with regular watering, feeding, and pruning.
Tomatoes can also be prone to pests and diseases, so always monitor your plants for any issues!
Watering
Both seedlings and mature tomato plants need regular watering — they grow best in consistently moist (but not soggy!) soil.
To check soil moisture, push a wooden stick about 5cm into the ground. If no soil clings to it when you pull it out, it’s time to water.
You can also poke your finger into the soil to feel if it’s dry.
The best time to water tomatoes is early morning. That keeps the soil moist for longer and gives any damp leaves enough time to dry out.
Always water around the base of the plant. Wet leaves can increase the risk of disease.
Moreover, avoid using a strong stream, as tomato stems can be fragile.
You can use a watering can with a rose spout or a soaker hose (if you have multiple plants).
You also need to water tomatoes more frequently in these cases:
- During flowering and fruiting
- When the weather is very hot or dry
- For tomatoes in pots or raised garden beds
Fertilising
Tomatoes are heavy feeders and need plenty of nutrients to grow well and produce lots of fruit.
Here’s a quick guide on fertilising your tomato plants at different growth stages:
| STAGE | FERTILISER TYPE |
|---|---|
| 2–4 weeks after planting | Balanced slow-release fertiliser (e.g., seaweed tonic) or none if the soil is rich |
| Established plants | Nitrogen-rich or balanced NPK fertiliser |
| Flowering and fruit set | Fertiliser that’s high in calcium, phosphorus, and potassium |
In the first 2–4 weeks after planting, you may not need to fertilise if the soil is already rich and well-prepared.
But if the seedlings look pale or weak, apply a balanced, slow-release fertiliser, like a seaweed tonic.
Once tomato plants are established, they need more nutrients to form strong stems and leaves.
At this stage, feed tomatoes with a good nitrogen source, like well-aged chicken manure or fish emulsion. A balanced NPK fertiliser also works.
During flowering and fruit set, switch to a fertiliser that’s high in calcium, phosphorus, and potassium. Examples are bone meal and kelp meal.
Avoid high-nitrogen fertilisers at this point. Excess nitrogen can lead to leafy growth but fewer fruits.
Always follow product instructions for when and how often to apply your fertiliser.
Pruning
Pruning tomato plants regularly can help you get more fruit. It also improves air circulation and prevents disease.
Indeterminate varieties need more pruning, while determinate types only need a light trim.
Here’s when to prune tomatoes:
- As they grow taller
- Once flowers appear
- As the growing season ends
As the tomato grows, remove any suckers. These are side shoots that sprout at a 45° angle from the “armpits” (between the main stem and a branch).
Check for any suckers every 2–3 days, and pinch them off while they’re still small.
Once the first tomato flowers appear, prune the lower leaves. Remove any that are diseased, yellowing, or touching the soil.
(This is usually the only pruning you need to do for determinate types!)
Towards the end of the growing season, top your tomato plant.
Trim off the tip of the main stem. Cut just above the last flower cluster that can still develop into fruit before the season ends.
This redirects the plant’s energy from leafy growth into producing fruit.
Common problems
Tomato pests and diseases can show up when growing conditions aren’t ideal.
Young tomato plants are especially vulnerable to pests. Common ones that can harm them include:
- Flea beetles: Leave small, round holes in leaves
- Hornworms: Can defoliate the plant and damage fruit
- Cutworms: Caterpillars that often attack young seedlings
Fungal diseases can also show up during rainy weather. Many of them cause discolouration on tomato leaves and stems.
Watch out for:
- Blight and leaf spot: Causes black or brown spots on leaves
- Fusarium and verticillium wilt: Leads to yellowing tomato leaves
- Powdery mildew: White powdery spots on leaves, stems, and fruits
Another common problem is blossom-end rot, which causes a dark, sunken spot on the bottom of the fruit.
It’s often linked to inconsistent watering, which blocks the plant from absorbing calcium from the soil.
Always keep a close eye on your tomatoes so you can catch any issues early. Also, monitor how much sun, water, and nutrients they get.
If you notice pests or fungal issues, remove any heavily affected leaves.
Then, try a neem oil spray. Mix ½ tbsp of neem oil with a few drops of dish soap and 1L of water. Spray the leaves once a week.
You can also grow disease-resistant varieties or grafted tomatoes with a hardy root system. Ask your local nursery for the best recommendations.
Harvesting Tomatoes
Knowing exactly when and how to harvest tomatoes can help you get the best fruit quality and flavour!
When do tomato plants fruit?
Tomato plants produce fruit around 50-100 days (2-3 months) after planting.
However, the exact timing varies depending on the type of tomato and growing conditions.
Some tomato varieties can give you a harvest as early as 50-60 days after planting, while others fruit after 90 days.
Also, keep in mind that tomatoes need warm temperatures to set fruit:
- Ideal daytime temp: 21°C–29°C
- Ideal nighttime temp: 12°C–24°C
Inadequate sunlight and water can also delay fruit production.
When to harvest tomatoes
Knowing when to pick tomatoes makes a big difference in fruit flavour, quality, and yield.
Generally, you have two options: harvest when they’re fully ripe or earlier.
Letting your tomatoes ripen on the vine will give you the best flavour.
Just wait until they reach their mature colour. Many varieties are deep red when ripe, but some turn orange, yellow, or even purple.
Ripe fruit will also feel firm with a slight give when squeezed and should come off the stem easily.
You can also harvest tomatoes earlier, during the breaker stage. That’s when you see the first hint of their mature colour.
This helps protect them from pests, disease, and splitting. It can also encourage the plant to fruit even more.
If you choose to pick tomatoes early, they’ll still ripen beautifully indoors.
Keep them in a well-ventilated area out of direct sunlight, ideally with temperatures between 21°C and 24°C.
How to pick tomatoes
The best time of the day to pick tomatoes is in the morning, before the heat of the day sets in.
To harvest, look for the “knuckle” or joint where the fruit stem meets the plant. Place your thumb over the joint, and twist gently until the vine snaps.
For varieties with thick stems or for clusters (like cherry tomatoes), use scissors or pruners.
Handle tomatoes with care and don’t pile them too high, as they bruise easily.
During peak season, check your plants every 2–3 days for ripe fruit. Regular picking can encourage more tomatoes to grow!
FAQs About Growing Tomatoes
Got tomato troubles? Here’s all the juicy info you need to grow them right!
Why put an egg in the hole when planting tomatoes?
Some gardeners bury a whole raw egg in the planting hole to give tomato plants extra calcium and phosphorus.
However, this can attract pests like rats and possums!
A better option is to use eggshells. Rinse, dry, and grind them into a fine powder using a blender or food processor.
During planting time, sprinkle 1–2 tbsp of powdered eggshells into the hole you’ve dug for the tomato seedling.
Mix the powder with the soil using a small trowel (or your hands), then place the seedling in.
You can also blend the powder into the top layer of the soil around the base of an established plant, or simply add it to your compost.
Why put baking soda around tomato plants?
Some gardeners apply baking soda onto the soil around tomatoes to make them sweeter. However, this is not proven and not ideal.
Baking soda is alkaline, and using too much can raise the soil pH.
This can cause nutrient imbalances in tomato plants as they prefer slightly acidic soil.
What can you plant with tomatoes?
Good companion plants for tomatoes include leafy greens like lettuce and spinach.
These are great choices if you’re planning to grow your own vegetable patch.
Other plants to grow with tomatoes are flowers like borage and marigolds.
These blooms not only brighten up your garden but also help keep harmful pests away from your tomatoes.
How to propagate tomatoes
You can grow new tomato plants from suckers — the tiny shoots that grow between the main stem and branches.
Suckers are usually pruned off since they can overcrowd the plant. However, they can grow into full tomato plants on their own.
Snip a healthy sucker (about 10–15 cm long) from the main plant.
Remove the lower leaves, then place the cutting in a glass of water or straight into moist soil.
If using water, wait until roots form and transplant into soil.
Keep the new plant in a warm, bright spot. Water regularly until it’s well established.
