How to grow tomatoes in Victoria

close up image of roma tomatoes on a vine

Clare Barry

Posted October 05, 2020

Tomato-growing tips from the Diggers Club’s tomato expert.

If you’re following the Australian tradition and planting your tomatoes on Cup Day, you could be missing out on a month or more of home-grown tomato goodness.

The Diggers Club’s tomato expert Jac Semmler says the ideal time to get your tomatoes in the ground is late September or October in all but the most frost-prone areas of Victoria, to give them the longest-possible growing season.

“Ideally you want to get them in before Cup Day,” says Jac. “I think Cup Day has just been a handy reminder for gardeners, a bit of a rule of thumb, to get a hurry along. I think it’s evolved over time from a lot of gardeners eating too much green tomato chutney in March when larger varieties haven’t ripened in time!

“With big beefsteak tomatoes it’s critical to get them in early and you wouldn’t want to leave it ’til after Cup Day – there’s just a higher risk the fruit might not get to the point of ripening, but you can still give it a crack with cherries and smaller varieties after Cup Day.”

The Diggers Club specialises in heirloom seeds and plants, and when it comes to tomatoes that means flavour, texture, and unusual shapes and colours.

“So many supermarket tomatoes are hybrids bred for particular attributes like uniformity, transportability and shelf life. Flavour is not one of those attributes,” says Jac. “I don’t want a tomato that tastes like water.”

She says that while tomatoes can be a bit fickle to grow for beginners they are a quintessential summer experience. “They do have beautiful rewards when you’re using them in salads or the kids can literally go into the garden and pick them off – the cherry tomatoes don’t make it as far as the kitchen very often!”

Jac adds that people can get stuck on a lot of rules with gardening, “but really it’s most important that people just get gardening. It’s an art and a science.”

bundle of red roma tomatoes

The Diggers Club’s Jac Semmler says October is the ideal time to plant tomatoes in Victoria.

Jac Semmler’s expert tomato-growing tips

Growing tomatoes from seed

If you want to grow from seed you need to start right on the cusp of spring, in late August or early September, so you can plant them out in late September or October and have a nice long season. The world’s your oyster if growing from seed because you get access to so many more varieties.

Growing tomatoes from seedlings

Growing from seedlings is a good option for beginners. The key is to choose good-quality, healthy-looking plants. Diggers Club members can order speedings (small seedlings ready to go in the ground) online at or buy the healthiest-looking plants you can find at quality nurseries. Bunnings Warehouse sells some Diggers Club heirloom seedlings. Many nurseries within metropolitan Melbourne are offering online orders with delivery or click-and-collect options.

Soil preparation for growing tomatoes

Tomatoes are heavy feeders so make sure you really prepare your soil by adding lots of potassium, rock dust, potash and blood and bone, but steer clear of nitrogen as it promotes leaf rather than fruit growth. Liquid feed every couple of weeks with a liquid fertiliser formulated for tomatoes. You can get this at the Diggers Club or good-quality nurseries.

Once in the ground

Because tomatoes are quite prone to disease, ensuring good ventilation is vital. So make sure your tomatoes are well staked, and prune out the laterals (side shoots) so air can move through the plants. There are arguments about whether removing laterals makes the plant more productive, but it does improve ventilation which helps manage disease.

Sun and water?

For tomatoes full sun is just a necessity. Tomatoes like a long hot summer, and if there are lots of spurts of cold weather through summer it can affect how they produce. Make sure you prepare your soil adequately and keep feeding throughout the season to guarantee success. You want to water thoroughly, but don’t waterlog your plants as overwatering can reduce the intensity of flavour. Stick your finger in the soil first to see whether it’s moist or needs water.

Is it really necessary to rotate where you grow tomatoes?

I never grow tomatoes in the same place I did the previous year as some of the diseases they are prone to are fungal and bacterial. Bacteria and spores can hang around in the soil for the next season and it’s very hard to eradicate both kinds of diseases naturally.

Growing tomatoes in pots

You can absolutely grow tomatoes in pots. Try Tasmanian chocolate, which is a dwarf plant that produces big tomatoes, or green grape which is also a dwarf plant. With a big enough pot you can even try growing some of the cherry varieties. You want the biggest pot possible and excellent potting mix (you get what you pay for), and you can train them around a bamboo teepee. Feeding regularly is really important, and keep the water up as pots can dry out quickly.


The Italian red pear tomato is a sweeter variant of the classic heirloom tomato.
Wild sweetie heirloom tomatoes are perfect for salads.
Cherry tomatoes can grow big and bushy.

Heirloom tomato varieties to plant today: Jac Semmler’s recommendations

Cherry tomatoes

Black cherry is really beautiful and I also enjoy wild sweetie which is great for kids, it’s a tiny tomato but really sweet. Also try pink bumblebee, which rates very highly in our taste tests, and crazy cherry which is a beautiful yellow tomato called crazy cherry because of its grape-like clusters of sweet tomatoes.

Salad tomatoes

Tommy toes have beautiful flavour and are a very reliable tomato. Another favourite is jaune flamme, I plant these out in late September and it always seems to be the earliest to harvest, they’re orange with a lovely flavour. I like green zebra because I think it’s fun to have a kaleidoscope of tomatoes, they have beautiful markings and a lovely flavor that’s a bit zesty.

Saucing tomatoes

Nonno’s Italian pear is always reliable, as is periforme abruzzese, known as granny’s throwing tomato. It’s a fluted tomato and you can just imagine someone grabbing it in their hand for throwing. It has thin skin and is quite fleshy with minimal seeds so really good for making passata.

Beefsteak tomatoes

Mortgage lifter is a great go-to, it’s such a heavy-yielding plant that produces really big beefsteak tomatoes. It was developed by an American farmer who literally paid off his mortgage by selling these tomatoes for a dollar each.