Two sets of eyes on every planting window: GardenBuddy.au and GreenThumb Magnets

A few weeks back a parcel of awesome A4 magnets landed in our inbox from the team at GreenThumb Magnets. Six A4 planting guides, the kind that live on the fridge door, wiht a coloured dot for every plant, every season and every one of the four Australian climate zones. The question that came with them was a good one. Would we check their planting windows against the data behind GardenBuddy.au, and say plainly where we disagreed?

We said yes before we had finished reading the email. This is exactly the kind of thing we reckon Australian gardening needs more of. Two small outfits, one printing charts and one building software, both trying to answer the same question for the same people: what do I put in the ground this month, where I live?

What we actually did

We did not only read and counted the dots by eye. Each scan was also rendered at high resolution and every dot was picked out by its colour, blue for cold, green for temperate, orange for warm and red for tropical, then checked back against the page. That gave us a clean table of 66 plants we could line up against our own planting data, which runs on seven weather based zones rather than four, and on a postcode rather than a state.

Where the two disagreed, neither of us got to be the referee. We went to independent Australian sources instead: ABC Gardening Australia, the seed companies, the fruit tree nurseries who know their chill hours. Whoever the sources backed, won.

Both of us learnt something

Here is the part we are proudest of, and it is not the part where we found things on their charts. It is the part where their charts found things on ours.

Their winter dot for snow peas in the tropics was right, and we had them marked as not worth trying. Darwin grows snow peas in the dry season and we now say so. Their chart had no tropical dot for peaches, and it was correct, because a peach in Cairns gets almost no chill hours and will not set fruit. We had been showing a plain June to August window as if it were Melbourne. And a handful of our perennials, the citrus and the blueberries and the banana, had been carrying a lazy “any month of the year” fill in the tropical zone. That is a default, not advice. All of it is fixed, 89 planting windows in total, and the corrected data has been live on GardenBuddy.au since the same day.

On their side, the big one was the wet tropics. A few temperate favourites, tomatoes, carrots, lettuce, pumpkin, were showing a tropical dot in spring and summer, and anyone who has gardened north of Townsville knows those go in during the dry, roughly April to August, and sulk or die once the humidity builds. A few cold zone summer dots were missing too, beans and zucchini and corn that every Melbourne gardener plants in December. And on a couple of herbs the greenthumbmagnets team pushed back with sources of their own, and they were right, so we conceded those. Well, that is how it should work. Their charts are being updated, ours already are.

Why a fridge magnet still matters

We build software, so you might expect us to tell you a magnet is old fashioned. We will not, because it is not. The fridge is where the household stands every morning, and a chart you see every day beats a tab you have to open. The GreenThumb guides are well made, clearly laid out, and cover the whole country in one glance: vegetables, fruits and berries, culinary herbs, medicinal and tea herbs, flowers, and a very handy one on how to store what you picked so it lasts the week. Ships free anywhere in Australia, straight from greenthumbmagnets.com.au.

What a magnet cannot do is know your postcode, your frost dates, or that your north bed is two weeks ahead of the south one. That is our job. So the way we see it, the two fit together. The magnet on the fridge tells you what is in season for your zone. GardenBuddy.au tells you what to do about it this week, in your beds, with your weather. If you already have a GreenThumb guide on the fridge, you are most of the way there. Put in your postcode and we will do the rest.

Thank you, GreenThumb

It takes a bit of nerve to hand your product to someone else and ask them to find the mistakes. The GreenThumb Magnets team did exactly that, took the findings graciously, argued the points worth arguing, and made us better in the process. We have been waiting on a partner like that for a long time. If you are after the printed guides, their planting data page explains how the charts are put together, and the shop is a click away from there.

GardenBuddy.au, built for subtropical vegetable growing at Dayboro, QLD. More about the project.

Published 26 September 2026.