How we calculated this
Formula: net $ saved per sq ft = yield (lb/sq ft) × retail price ($/lb) − input cost ($/sq ft).
FAQ
What is the highest-ROI vegetable to grow?
By net dollars saved per square foot, basil tops the table at about $6.10/sq ft, followed by cherry tomatoes ($4.97) and parsley ($4.91). The pattern is consistent: the best returns come from compact, cut-and-come-again crops (herbs, leafy greens) and prolific fruiting plants like cherry tomatoes. They combine a decent retail price with a high, repeated harvest from a small footprint. Note that basil’s price is a representative $8/lb figure, not the misleading $85/lb you would get by extrapolating a tiny 0.75-oz clamshell.
Why are potatoes and onions low ROI?
It is not that they grow poorly — potatoes actually have one of the highest yields in the set at 1.5 lb/sq ft. The problem is the retail price. Potatoes sell for only about $0.86/lb and onions for $1.85/lb, so even a heavy harvest converts to few dollars. Potatoes also carry a real seed-potato cost (~$0.40/sq ft) that drags net down further. These are genuine economics, not a quirk of our model: storage staples are cheap to buy, so growing them rarely beats the store on pure cost.
Are these 2026 prices?
Partly. Most fresh-vegetable prices come from USDA ERS 2023 retail scanner data, which is the most recent complete year ERS publishes. Crops that ERS does not track — herbs, garlic, beets, snap peas — use 2026 USDA AMS terminal-market reports or retail aggregators. A few items (carrots, potatoes) use BLS April 2026 average-price data. We flag the volatile ones: onions spiked to roughly $2.69/lb in April 2026, but we kept the steadier $1.85 ERS figure so the ranking is not distorted by a temporary spike.
Do these numbers include my time?
No. This is a pure cost comparison: harvest value minus the dollar inputs (a flat soil-amendment charge plus seeds, transplants, seed garlic, or seed potatoes). It does not value your labor, water beyond what is modeled, equipment, or the enjoyment of gardening. If you priced your time, almost every crop would look worse — people garden for flavor, freshness, and the experience, not just to beat the grocery store. Treat the ROI here as directional, not penny-accurate.
Related guides
Planning what to grow next to what? See our companion planting guide. Want to keep input costs down? Our best garden tools guide covers the gear that actually earns its keep.
