About My Planting Calendar

My Planting Calendar is a free set of planning tools for home vegetable gardeners in the United States. The centre of it is a planting calendar generator: you tell it where you garden — by state, USDA zone, or your own frost dates — and it works out indoor sowing, transplanting, direct sowing and harvest windows for dozens of crops, plus succession sowing dates.

Around it are single-purpose calculators for spacing, soil and mulch volume, seed starting, grass seed and companion planting, plus reference pages for every crop, zone and state, and a library of practical guides.

How the dates are worked out

Every planting date is counted forwards or backwards from your average last spring frost and first fall frost. Crop-specific offsets (how many weeks before the last frost to start tomatoes indoors, how long after it to sow beans, and so on) come from US Cooperative Extension planting guides, cross-checked against more than one state source. The method is described in full on the data sources page and in the frost dates guide.

What it is not

It is not a guarantee. Frost dates are averages, weather varies, and a south-facing bed behaves differently from a frost pocket half a mile away. Treat the output as a strong starting point and adjust it to what actually happens in your garden.