Guides
Garden guides you can check your own math against
Three in-depth guides, written from the same numbers Smart Garden Planner uses in its own tools — bed spacing, frost dates by zone, and sourced companion planting records. Every claim links back to the tool or the university source behind it, so you can verify it before you spend a season on it.
Space & yield math
How many plants fit in a 4×8 raised bed?
The exact plant counts for 22 vegetables in a 4×8 ft bed, the spacing math behind them, and how to find out what your own bed actually harvests.
Read the guide· 7 min read · updated 2026-11-08
Season timing
Can you fit a second crop before frost?
Frost-free days by zone, the planting windows our calendar uses, and how to work out whether a bed has time for one more planting.
Read the guide· 8 min read · updated 2026-11-08
Companion evidence
Do marigolds actually keep pests away?
What university research and extension sources do and don't support about marigolds, and how to tell a proven pairing from garden folklore.
Read the guide· 6 min read · updated 2026-11-08
Companion planting
Look up a crop to see which plants may help it, which share pests or diseases, and how strong the evidence is. Each crop has its own full guide page.
Planting calendars
Enter your ZIP to get your USDA zone, estimated frost dates and planting windows — or open the calendar page for your zone directly.
Put the numbers to work in your own beds
Plan each bed, get planting reminders, and log harvests in pounds and ounces so next season's plan is based on what your garden actually gave you.