Dayboro Veggie ROI Calculator — Is It Cheaper to Grow or Buy?
Real supermarket prices vs actual growing costs — find out which vegetables save you the most money
We pull current retail prices from our price tracking system (updated regularly from major Australian supermarkets) and compare them against what it actually costs to grow each crop in Southeast Queensland. The growing cost estimates account for seeds, water at SEQ rates ($3.50/kL), and fertiliser — but not your labour, because honestly, if you're counting that, you should probably just go to Woolies.
Is It Actually Cheaper to Grow Your Own Vegetables in Dayboro?
The short answer: for most crops, yes — sometimes dramatically so. But not for everything, and the devil is in the details. Potatoes at $4/kg from Woolies are genuinely hard to beat once you factor in the space they need and the water they drink. Herbs like basil, on the other hand, are an absolute rort at the supermarket — a tiny punnet for what you could grow by the bucket-load for almost nothing.
The key factors that swing the equation are yield per square metre, days to harvest, and the current retail price. Crops that produce heavily in a small space (think zucchini, cucumbers, tomatoes) tend to deliver the best return on your gardening investment. Crops that take up heaps of room and produce modest yields (corn, pumpkin) can actually cost you more than buying them, unless you have space to burn.
What Costs to Consider When Growing Your Own
The calculator accounts for three direct costs:
Seeds and Seedlings
Seed packets from Bunnings or your local nursery typically cost $3–$8. Premium varieties (heirloom tomatoes, fancy herbs) can cost more. If you save seeds from season to season, this cost drops to near zero after the first crop.
Water
SEQ water rates are approximately $3.50/kL (1,000 litres). The
calculator uses crop-specific watering needs — a thirsty crop like cucumber
at 12L/week costs roughly 22 cents per week to water. Over a full growing season,
water costs are typically $1–$5 per crop. Mulching heavily reduces this
by 30–50%.
Fertiliser
A basic seasonal fertiliser cost of $1–$5 per crop depending on how hungry it is. Heavy feeders like tomatoes and capsicum need more; legumes (beans, peas) fix their own nitrogen and need very little. If you compost, your fertiliser cost approaches zero.
What We Don't Include
Labour: The calculator doesn't price your time. If your hourly rate matters, gardening is rarely competitive with Woolworths. But most backyard gardeners don't garden for the wage — they garden because they enjoy it.
Setup costs: Raised beds, soil, tools. These are one-off costs that amortise over many seasons. The break-even analysis (members only) factors in a typical $150 raised bed setup.
The Most Profitable Vegetables to Grow in Southeast Queensland
Based on current supermarket prices and realistic SEQ growing conditions, herbs consistently top the profitability charts. Basil retails for over $30/kg at the supermarket but costs almost nothing to grow. The same goes for most leafy herbs. Among "proper" vegetables, lettuce, spinach, and kale deliver strong returns because they produce multiple harvests from a single planting (cut-and-come-again), their retail prices are high per kilogram, and they grow fast in Dayboro's climate.
Crops that take up less space tend to win on ROI. Lettuce at 0.15 m² per plant with 52 days to harvest is hard to beat. Compare that to pumpkin at 2 m² per plant and 102 days — pumpkin needs 13 times the space and twice the time for a modest retail price of around $3/kg.