Grow and save. The honest version.
Grocery prices are up and the food bill is the one line most households cannot dodge. Some vegetables genuinely beat the supermarket. Most do not. This page prices both, with the pots and potting mix counted, and tells you which ones you can plant this month where you live.
Supermarket prices: Woolworths NZ online, 16 September 2026, in New Zealand dollars. Planting months: Planting Season's regional data for all nine New Zealand climate regions.
What you could save this month
Pick your region, what space you have and the month you are planting. The calculator only counts crops that can go in now where you live, prices the setup as if you bought everything new, and tells you the week each crop pays for itself. Pots means a 25 cm pot or a 40 cm trough per crop; a bed means a standard raised bed of about 1.2 by 3 metres, with mint and a few herbs still in pots. Less room than that? Drop crops from the bottom of the table first, they save the least.
| Plant now | Replaces, per week | Setup | Pays back | Season net |
|---|
"Win" means the crop clears its setup cost inside one season with room to spare. "Fair" means it about breaks even the first season and pays properly from the second, once you own the pots. Every crop here beats the supermarket once the pots are paid for; the question is only how soon.
Worth waiting for
Good savers that are out of season in your region right now. Plant them in the month shown and you will not waste the seedlings.
Keep buying these
Cheap at the shops, slow and space-hungry in the garden. Grow them if you enjoy it, not to save money.
- Potatoes Buy it $3.99 a kg loose, under $3.65 a kg in a 4 kg bagTen plants in 1.5 square metres of bed give about 15 kg after 14 weeks. That is $55 of potatoes, less about $15 of seed potatoes, for a quarter of a bed all season. Buy them, unless you want the fun of digging them.
- Carrots Buy it $2.25 a kgA square metre of bed gives about 4 kg in 12 weeks, under $10 of carrots. Grow them for the taste, not the savings.
- Brown onions Buy it $3.50 a kg loose, about $3.05 a kg in a 1.5 kg bagSix months in the ground for something that costs about $3 a kilo in a bag. The worst return in the garden.
The $29.29 basket
| Basil, 15 g punnet | $5.25 |
| Coriander, 100 g bag | $4.25 |
| Mesclun, 120 g | $4.15 |
| Baby spinach, 120 g | $3.90 |
| Cherry tomatoes, 180 g | $4.80 |
| Spring onions, bunch | $2.49 |
| Silverbeet, 500 g bunch | $4.45 |
| Every week, one shop | $29.29 |
Woolworths NZ online, 16 September 2026. Seven lines most households buy every week in spring and summer, and every one of them grows in a pot.
That basket is $351 over a 12-week season and it is the part of the shop that gets thrown out: half a bag of coriander gone to sludge, the mesclun that turned slimy on day four.
Grown in an existing bed, the same seven crops cost about $45 in seed and seedlings. You are roughly $310 ahead in the first season.
Grown in pots bought new, the setup is about $180 the first time, so the first season is only $170 or so ahead. The pots and troughs last for years, and from the second season it is the full $350 again. That is the honest number, and it is still a good one.
Plant the same crops in the wrong month and the number is negative. Which is the whole point of the next section.
The $150 mistake
Most people who set out to save money on vegetables spend more than they save, and it is nearly always the same three ways.
The fix for the first mistake is knowing what to plant this month in your region. That is what the free Planting Season app does: pick your region, open it, and it shows you what goes in the ground now, what to hold off on, and when to pick. Think of it as insurance on the seedlings.
Plant the right thing this month
The free app shows what to sow now in your region, sets reminders and tracks your harvest. No card needed.
Open the free app →Set up for less
The setup costs on this page assume you buy everything new. Most people do not have to.
- Free compost and subsidies. Many councils subsidise compost bins and worm farms, and some give away seedlings and run free workshops. Check your council's freebies before you buy potting mix.
- Grow from seed. A $3.70 packet of lettuce seed is hundreds of plants. A punnet of six seedlings is about $4.20. Seed raising and seed saving get the cost of a crop close to zero.
- Make your own soil. Compost and a worm farm turn the scraps you already pay for into the potting mix you would otherwise buy.
- Buckets and troughs. A 20 L bucket with holes drilled in the base grows a tomato as well as a $30 pot does. Polystyrene fish and broccoli boxes from the greengrocer grow salad greens for nothing.
How to grow the winners
What to plant this month, by email
One short email at the start of each month with the crops to sow in your region and the ones to skip. No spam, unsubscribe any time.
Frequently asked questions
Prices are Woolworths NZ online (formerly Countdown) on 16 September 2026, in New Zealand dollars, and will move with the season and specials. Setup costs are estimates from typical Bunnings and Mitre 10 prices for pots, troughs, potting mix, seedling punnets and seed packets. Yields are averages for a New Zealand home garden with normal care. Your results will vary with soil, weather, pests and how often you pick.