"Growing your own is cheaper" is true often enough to be worth doing, but it isn't true evenly across every crop, and knowing which vegetables actually deliver a real saving is the difference between a garden that pays for itself and one that's a pleasant hobby with a grocery-store-sized price tag attached.
Tomatoes are the clearest example of a genuine win. Growing a tomato plant from seedling to full crop costs around 25 dollars in seedlings, stakes, and feed, against a grocery-store value of roughly 90 dollars once you account for the volume a single productive plant produces over a season. That's not a marginal saving, it's more than triple the outlay back, and it's a big part of why tomatoes are the single most commonly grown vegetable in New Zealand home gardens.
Potatoes tell a similar story with slightly less dramatic numbers: about 15 dollars to grow a worthwhile crop against roughly 60 dollars of equivalent supermarket potatoes, still a strong return, and one that gets better in a season when supermarket potato prices spike, which they do periodically depending on the commercial harvest.
Potatoes tell a similar story with slightly less dramatic numbers: about 15 dollars to grow a worthwhile crop against roughly 60 dollars of equivalent supermarket potatoes, still a strong return, and one that gets better in a season when supermarket potato prices spike, which they do periodically depending on the commercial harvest.
Feijoas make the case on a longer timeline. A tree costs more upfront, and takes two to three years to bear a full crop, but a single mature, well-pollinated tree producing 10 to 20 kilograms a season against a grocery value of around 120 dollars turns a one-off planting cost into a saving that repeats every autumn for the rest of the tree's life, easily two decades or more. Judged only on the first season, feijoas look like a poor investment. Judged over the tree's lifetime, they're one of the best-value plantings available to a home garden.
Not every crop clears this bar. Slow-growing, low-yield, or genuinely fussy crops can cost close to what they'd save, once seedlings, specific soil amendments and the occasional replanted failure are factored in, which is a real reason some gardeners feel their garden "isn't saving them anything" even while growing plenty of food. The honest answer isn't that growing your own doesn't work, it's that the saving is concentrated in a smaller list of reliable, high-yield crops than beginner enthusiasm usually accounts for.
The practical takeaway is to weight a first garden toward the crops with the clearest return, tomatoes, potatoes, courgettes, leafy greens and herbs among the standouts, and treat anything genuinely difficult or low-yielding as worth growing for taste and freshness rather than for the household budget. A garden built around the reliable savers pays for itself within a single season and keeps paying every year after.