Tomato Growing Guide: from seed to kitchen

How to Grow Tomato

The essential guide to growing tomato from seed; with notes on germination, cultivation, harvest and even kitchen uses.

A quick guide to tomato types & how to use them:

Determinate (“bush”) – compact plants that set most fruit in one flush. Great for back-yard growers who want a glut for bottling, sauces or passata; mild, balanced flavour.
Indeterminate (“vining”) – lanky plants that fruit continuously until frost. Choose for salads, sandwiches and snacking when you want a long harvest of full-flavoured fruit. Need staking/support.
Semi-determinate – midway in height and harvest window; ideal for small trellises and mixed kitchen use.
Parthenocarpic/seedless – set fruit even in cool, wet or very hot spells; handy in short seasons or greenhouses. Flavour similar to parent line, seeds absent or tiny. For example 'Legend'.
Cherry & grape – bite-sized bursts of sweetness for salads, lunchboxes and roasting whole.
Paste/Roma – dense flesh, low juice; best for sauces, sun-drying and pizza toppings.
Beefsteak & heirloom slicers – big, juicy, often multicoloured; showcase fresh in burgers and caprese, or slow-roast for rich umami.

Seeds per gram: 250 – 350 seeds

Germination temperature: 21 – 27 °C; sprout in 7-12 days when kept warm and moist.

Feed requirements:

Moderate overall – mix 4-6 litres/m2 of compost plus a handful (50 g) of balanced organic fertiliser into planting holes, then side-dress with a high-potash feed as first trusses set.
Ensure adequate calcium (lime, gypsum or crushed eggshell) to prevent blossom-end rot.

Growing Notes:

Sowing Direct:

This is for warmer regions where the soil temperature is above 18°C and nights stay above 18°C.
Sow 4-6 seeds directly in the garden 5-8 mm deep using the spacings below.
Keep soil moist.
A spell of cooler weather will slow germination.
Thin to strongest seedling once there are 4 true leaves.

Germination & Raising Seedlings:

Sow indoors 6–8 weeks before the last frost. Use a fine seed-raising mix, cover seed 5-8 mm deep.
Maintain 21-24 °C bottom heat until germination, then grow on at 18 – 20 °C in bright light to avoid legginess.
Pot up to 7 cm pots at first true-leaf stage; feed fortnightly with dilute seaweed or fish emulsion.

Transplanting & Spacing:

Plant out after all frost danger when night minima stay above 10 °C. Harden seedlings for a week outdoors first.

Determinate & dwarf: space 45 – 60 cm apart.
Indeterminate/semi-determinate: 60 – 90 cm apart with strong stakes, trellis or cages 1.8 – 2 m tall.
Set seedlings deeply, burying the stem up to the top two leaf sets – buried stems root readily and anchor plants.

Growing On:

Water deeply at soil level. Mulch thickly to keep moisture even and reduce splitting.
Prune indeterminates to one or two leaders, removing side-shoots weekly for larger, earlier fruit and better airflow. Determinates need little pruning.
Support heavy trusses with soft ties; remove lower leaves once fruit has set to improve air movement and reduce blight risk.

Common Problems & Remedies:

Aphids, whitefly – spray with insecticidal soap, encourage ladybirds.
Fruit fly (QLD & NT) – use exclusion bags or 2 mm netting once fruit is pea-size, and hang protein traps.
Early & late blight, leaf spot – rotate crops 3–4 years, water at root zone, apply copper or potassium bicarbonate at first sign.
Blossom-end rot – keep soil evenly moist and ensure calcium; avoid excessive nitrogen.
Splitting – maintain steady watering, pick just before heavy rain, avoid rough handling of cold seedlings.

Harvesting & Storage:

Pick when fruit shows varietal colour and yields slightly to a gentle squeeze.
- If birds or pests are a problem as fruits ripen harvest a little early and let ripen further in the kitchen.
Twist or clip fruit from the vine; leave calyx attached to slow dehydration.
Store at 15–20 °C out of direct sun for best flavour. Refrigerate only fully ripe fruit you cannot use within two days.
Green fruit can ripen indoors in a single layer at 18 °C, or use for chutney and pickles.

Home-grown tomatoes reward you with unmatched sweetness and aroma – whether you bottle a year’s supply of Roma sauce or snack on sun-warmed cherries straight off the vine, every gardener’s first bite is summer captured in a seed.