Disclaimer

Independence and non-affiliation

PlantingCalc is an independent, privately operated gardening reference site. We are not affiliated with, endorsed by, or sponsored by the U.S. Department of Agriculture (USDA), the National Oceanic and Atmospheric Administration (NOAA), any state university or cooperative extension office, any seed company, any nursery, any government agency, or any commercial gardening brand. Any brand names, product names, or logos that appear on this site are used for identification and editorial purposes only. All trademarks belong to their respective owners.

Data sources and accuracy

Our calculators and growing guides are built on publicly available data from the USDA Plant Hardiness Zone Map, NOAA 30-year climate normals for frost dates, and peer-reviewed agricultural extension publications from land-grant universities. We do not alter the underlying government datasets themselves — we reformat and compute on them so they're easier to apply to a real backyard garden.

While we work to keep the data current and the formulas well-calibrated, the Service is provided as is. Agricultural data ages over time, zones change on multi-year review cycles, and published averages hide significant regional variance. PlantingCalc makes no warranty, express or implied, that its calculations are accurate, complete, current, or fit for any particular purpose. For gardening decisions with significant financial, ecological, or health consequences, verify with your local extension office, licensed nursery, or soil testing laboratory.

Calculators are estimates, not prescriptions

A calculator that returns "plant tomatoes the week of May 15" is returning an estimate built on averaged regional data. Your specific microclimate — a south-facing wall, a cold pocket, a container on a hot roof, a raised bed with atypical soil — can shift the correct date by one to three weeks in either direction. Treat every output as a starting point, not a prescription, and adjust based on what you observe in your own garden over multiple seasons.

Not professional advice

PlantingCalc publishes general information about home gardening. Nothing on the site is horticultural, agricultural, medical, nutritional, or pesticide/chemical-application advice. We are not agronomists or extension agents, and reading this site does not create a professional relationship of any kind. For individualized advice — especially about chemical applications, soil remediation, or any plant that will be consumed — speak to a qualified licensed professional.

Plant identification and foraging

Some PlantingCalc content mentions specific plant species and cultivars. None of it is intended as a foraging guide or as identification advice for consumed or medicinal plants. Plant identification errors can be fatal. If you cannot identify a plant with total certainty, do not consume it and do not apply it to a person or animal.

Editorial analysis

Some pages on PlantingCalc include original editorial analysis — for example, plain-language explainers for each growing zone, commentary on how a specific calculator should be used in practice, and discussion of common failure modes. Those sections represent our own interpretation of the underlying data at the time of writing and are clearly separated from the raw calculator outputs. They are not pronouncements from USDA, NOAA, or any university extension.

Advertising and affiliate relationships

PlantingCalc may display contextual advertising from third-party networks to help cover operating costs. Any ads shown are clearly labeled as such and are not an endorsement of the advertised product or service by PlantingCalc. Ad placement does not influence calculator outputs, growing-zone recommendations, or editorial analysis.

Where PlantingCalc includes affiliate links to physical products (for example, gardening tools or soil amendments), those links are clearly disclosed in line with FTC guidelines and on our affiliate disclosure page. Affiliate relationships never influence which products we mention, how we describe them, or what our calculators recommend.

Errors and corrections

If you believe a page on PlantingCalc contains an error — an incorrect zone, a miscalculated spacing recommendation, an outdated frost-date value, or a factual error in an editorial section — please contact us with the page URL and a description of the problem. We review every correction request and update against the underlying source data.