Survival Garden Calculator

How much land does it actually take to feed a family?

The question sounds simple but the answer varies enormously depending on what you're growing, how skilled you are, and what climate you're in. Traditional estimates from smallholding literature suggest 0.4 hectares (4,000 m²) per person for full caloric sufficiency using low-tech methods. Modern intensive methods — raised beds, companion planting, succession sowing — can produce the same calories from as little as 100–200 m² per person.

For most Australians, complete food self-sufficiency isn't the goal — supplementing grocery bills with fresh vegetables, reducing food miles, and building resilience is. A well-managed 25–40 m² garden can supply a family of four with much of their vegetable needs for a good part of the year.

• Calorie-dense crops are essential for self-sufficiency: Leafy greens are nutritious but low in calories. To actually feed yourself, you need calorie-dense staples: potatoes (~750 kcal/kg), sweet potato (~860 kcal/kg), dried beans (~1,400 kcal/kg), pumpkin (~450 kcal/kg), and corn (~365 kcal/ear). These should anchor any serious food-growing plan.
• Australian growing seasons vary dramatically: A tropical garden (Darwin, Cairns) can grow year-round. In Hobart or alpine Victoria, the growing window can be as short as 5–6 months. This fundamentally changes how much space you need — more restricted season means you need more space to produce the same annual yield.
• Water is the real constraint in Australia: Most of Australia is semi-arid. A food garden needs 20–40 litres per m² per week in summer. A 100 m² garden needs 2,000–4,000L/week at peak. Rainwater tanks, greywater reuse, and drip irrigation are essential for any serious food garden.
• Succession planting multiplies your output: Rather than planting all your lettuce at once and watching it bolt, plant 6 plants every two weeks. The same applies to beans, beetroot, and carrots. This technique can double effective yield from the same space.
• What to grow first: High-value crops that are expensive to buy and easy to grow deliver the best ROI: tomatoes, zucchini, silverbeet, herbs (basil, parsley, rosemary), and climbing beans. Save the complex crops (brassicas, melons, corn) for when you have experience.