Listen
Photo: Kath Irvine / Edible Backyard
Tomatoes are a favourite backyard crop but can be tricky to grow.
Luckily, organic gardener Kath Irvine, who is also the author of The Edible Backyard, has some simple strategies to set you on the path to an abundant crop.
She told Saturday Mornings that warm air and soil, good drainage and compost were all on her list.
"The most important thing for tomatoes is they're a summer crop and they need the warmth.
"If you're raising them from seed, it needs to be 20 degrees Celsius in that seed tray and when you're planting them out it can be a little bit cooler but [still] around about 18C in your soil."
And for gardeners who did not have a greenhouse, Irvine recommended using a big black plastic pot as an alternative.
"Not often [that] I advocate for plastic but in this regard, it's a real winner because it really warms up the soil and you can get your tomatoes growing a little bit earlier."
She also recommended getting a soil thermometer, which was "a cheap handy tool" to check temperatures.
Tag teaming with the warmth was watering and drainage.
"That makes an epic difference for tomatoes [that] hate to be wet.
"Eighty percent of people's problems with their tomatoes is they're just watering too much," she said.
"My initial test used to be if I pushed my finger into the soil and it felt a bit moist at my fingertip, then I would leave my tomatoes until another day. It took me quite a while to work up to that because it feels just too dry. But gosh, my tomatoes really started to flourish.
"This is once they're established I have to say, this is not when they're wee little babies."
And Irvine cautioned any shortcuts when it came to drainage.
"Sometimes people think, 'oh, I'm in a poorly drained area, I'll just make a raised bed up on top', it's not actually a very good hack at the end of the day because the health of the soil on top is connected to the health of the soil below.
"Poorly drained soil is airless and therein lies the problem because the water displaces the air and in that scenario, fungal diseases just run amuck and they really thrive."
Another option for gardeners with poorly drained areas was to simply grow tomatoes in pots, said Irvine.
"They're not actually a very deep-rooting plant so they grow well."
Kath Irvine. Photo: Kath Irvine
The right variety of tomato can also play an "enormous role" in how well they grow, said Irvine.
"Not all tomatoes are going to love your place and the way to find out is local gardeners, gardening groups, that kind of thing ... get advice from them about what tomatoes grow really well and save the seed.
The other thing to ... really focus on is feeding. It's another thing like watering, most people I find solve problems when they stop overwatering and its the same with overfeeding."
Irvine's advice is to just play it simple - good homemade compost, vermicastings and seaweed.
"Very, very simple things, not rich stuff."
"Fish frames [are] wonderful for the whole garden ... my general rule is that you get all your organic matter going into your compost and then when it breaks down in your compost, you really get that mineral availability from whatever raw ingredients you've got."