Plan bulb onions for canning, compare planting systems, and choose a day-length type suited to your latitude. Hardiness zone describes winter minimum temperature. It does not replace frost dates, day length, soil temperature, or current weather. Nothing is shared until you choose a lookup button. ZIP lookup uses PHZMAPI. “Use my location” sends coordinates to BigDataCloud only to obtain a ZIP, then sends that ZIP to PHZMAPI; coordinates are not stored by this site. Verify the result on the official USDA 2023 map; manual override always remains available. Zone is only one factor. Day length, disease pressure, storage quality, maturity, and use may be more important. Usually best at lower latitudes; choose a firm storage or processing cultivar recommended locally. Often suited to middle latitudes; confirm local adaptation, disease resistance, firmness, and storage life. Usually best at higher latitudes; storage types suit a harvest held for later canning. Start seed about 10–12 weeks before transplanting where the cited northern guidance applies. Check local frost, soil, and forecast conditions. Current weather is not loaded automatically; check the local forecast and soil before planting. Plants = household annual target ÷ selected yield per plant, rounded up. Area or row units = target ÷ compatible cited yield, rounded up. “Typical” uses the cited midpoint. University of Minnesota Extension crop and field planning dataYour growing location
Plants and space calculator
Space by planting style
Preservation-suitable variety direction
Short-day onions
Intermediate-day onions
Long-day onions
Planting and indoor-start timing
Canning recipes using onions
Sources, formulas, and limits
