Free Gardening Tools for Real Gardeners
GardenCalc was built by a designer and gardener based in Texas — because planning a great garden shouldn't require a horticulture degree.
Built for Gardeners, by a Gardener
GardenCalc is a free gardening tools site built by a designer and lifelong gardener based in Texas. The idea started simply enough: every spring, figuring out when to start tomatoes indoors, when to direct sow beans, and when to actually stop worrying about frost required digging through multiple extension office PDFs, outdated charts, and ZIP code lookups scattered across half a dozen websites.
The solution was to build one place that does the math for you. Enter your ZIP code and get your frost dates, your seed starting schedule, companion planting advice, and bed layout — all in one session, all for free.
Every calculator on GardenCalc is grounded in real data: frost date lookups use NOAA's 30-year climate normals, planting calendars reference university extension service guidelines, and companion planting recommendations are drawn from decades of agricultural research and experienced grower feedback. We update the data as science evolves and as our community surfaces corrections.
We believe that accurate gardening information should be accessible to everyone — from the homesteader planning a half-acre kitchen garden to the apartment dweller growing herbs on a balcony. No paywalls, no required accounts, no upsells. Just tools that help your garden thrive.
Explore All Tools →GardenCalc at a Glance
Our Values
The principles that guide every tool we build and every article we write.
Always Free
Great gardening knowledge should be accessible to everyone regardless of budget. Our core tools will always be free.
Accuracy First
We source data from NOAA, USDA, and university extension programs. We update calculations when science evolves.
Sustainability
We promote organic practices, companion planting, and soil health because a healthy garden starts with healthy soil.
Accessibility
Every page is mobile-responsive, screen-reader friendly, and optimized so it loads fast even on slow connections.
Community-Driven
Our best features come from gardener feedback. We read every email and implement suggestions that help the most people.
Privacy Respected
We don't sell your data. ZIP codes entered in our tools are never stored or associated with any personal information.
Share Your Feedback
GardenCalc is actively being improved based on gardener feedback. If you have suggestions, found a bug, or want to see a new feature — I'd love to hear from you.
Open Feedback FormFeedback is reviewed regularly and helps shape what gets built next.