If you’re wondering if you can grow Tomatoes in September, unless you are in a warm climate zone – the answer is probably not. While the plant will most likely not drop dead, nor will it thrive.
The southern part of Australia is still coming out of Winter, and the ground is still quite cold.
Let’s keep in mind that Tomatoes originate from South America, growing in warm and moist areas. A Tomato seedling raised in a heated greenhouse will struggle when moving to the great outdoors with low night time temperatures.
The main misconception people have is that their Tomatoes will get a “head start” and produce earlier and therefore provide a longer harvest season. There are two reasons why this doesn’t work out – 1) Because the roots will not develop quickly in cold soils, meaning the plant doesn’t show strong growth above ground and 2) If the Tomato starts to flower, the low air temperatures will inhibit pollination and therefore fruit development.
I have had a few self-seeded tomatoes pop up in Winter, and these have never produced stronger or earlier crops than the ones I plant out in November.
It really is best to wait until the soil has warmed up, which in the temperate zones of Australia is October and November. If you have a temperature probe in your kitchen, go ahead and stick it in the ground to see how cold it is. I recommend letting the soil warm to at least 18ºC before putting Tomatoes into the ground.
Then Why Are They In The Shops?
Early in the season we will see a variety in the garden centres called Burnley Bounty which is cold tolerant, but will still be damaged by frost. Apart from that, I am not really sure why garden centres are selling Tomato seedlings in Winter!
Some people purchase Tomato seedlings in early September, and then pot them up into larger pots, keeping them in a warm and sheltered spot until they are bigger and the soil is warmer. If you do this, use the black plastic post and position them to get morning sun, so that they roots start to warm up quickly each day.
Keep in mind that potted plants dry out quickly and need extra attention to make sure they don’t blow over or become straggly through lack of light.
Can You Grow Tomatoes In September?
Technically the answer is yes, but for a much better result – wait until late October/early November.
Use the time in September to prepare your soil and get your irrigation systems in order, so that when your Tomato seedlings go in they will have a great start.