tomato guide 2 – Seed sowing and transplanting

tomato guide: Sowing & Transplanting Seedlings

When choosing which seeds to buy try to stick to ‘heirloom’ or ‘open-pollinated’ varieties rather than hybrids. That way the seed you save from your fruit this year will produce the same type of tomato when you grow it again next year.

Most seed packets will produce more plants than you can grow at once, so share some with friends and neighbours.

tomato mixed variety close up bowl
green sprouting tomato seedlings

Scrounge around for some small pots or containers to start your seed in. Get creative with egg cartons, toilet rolls, old milk bottles, used berry cartons, as long as you can punch a few holes for drainage. Fill these about 1cm from the top with a seed raising mix or a well-sifted compost and water it in well. Scatter your seeds on top, aiming to have them about 2cm apart. This way when you transplant them they won’t have their roots entangled with each other. Lightly sprinkle more soil on top and give them a gentle water to avoid washing the seed away. Place them in a warm, well-lit, sheltered spot, a sunny windowsill is ideal. If you can find some old windows or glass panels you can rig up a little cold frame in the backyard with some bricks or a polystyrene box. If you are a mad keen propagator you might consider investing in a little heat mat to warm the soil up and speed up germination.

In about a week or so you’ll see some seedlings rearing their green little heads! The first leaves are called ‘seed’ leaves and look quite different to the ‘true’ leaves of the tomato plant. Never fear, in another couple of weeks (depending on how warm it is) they will have true leaves and stems strong enough to transplant into the garden or pots you want to grow them in.

Here’s where those who have bought/been given their seedlings can listen in again. Maybe like me your friendly southern European neighbours have emphatically cajoled you over to their backyard to take home some unidentified-but-guaranteed-big-fat-fruit-bearing tomato plants! In this case, count your lucky stars and try to get invited to the chutney or passata making party at the end of summer.

So when is the right time to transplant? Some people say when the soil is warm enough to sit on with a bare bottom! Some say after Grand Final Day but before Melbourne Cup. More cold-tolerant varieties can be planted earlier and you should at least wait until the threat of frost is over. You might find the ones you plant later catch up to those you planted earlier! 

fresh green tomato foliage growth
tomato seedling planting tray
tomato seedlings ready for transplant

In any case you should always transplant in the cool of the morning or on an overcast day. High winds and hot sun can dry out the tender roots of your seedlings, increasing their transplant shock and getting them off to a wobbly start. Give seedlings a good water, preferably with seaweed extract, before you even think about planting them out. Pick a spot in the garden that gets a good amount of morning sun. 

Your soil or potting mix should be enriched with well-aged compost and manure, and adding a little organic slow release fertiliser or blood and bone will ensure good plant. If you are growing in pots make sure they are at least 40cm in diameter and as deep. 

Tomato plants have the amazing ability to grow roots out of anywhere in their stem, so planting them deeply (about 5cm) helps to stabilize the plant. How far apart you plant will depend on the variety; determinate varieties will need less space but for indeterminate plants I leave about 60cm between each to allow for good airflow. Give the soil around them a good soak with seaweed extract and water, and mulch them with a straw mulch, keeping it a little away from the stem. This keeps in moisture and stops weeds from popping up. 

If you want to have a tomato taste test party in the summer make sure you label your plants, otherwise you won’t know your Golden Sunrise from your Yellow Cherry Honey Bee! But what about staking you ask? Pruning? Watering? Fertilising? All in good time my friends. For now you can relax and dream of gazpacho.

ripe tomato close up vine


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