growingseason

Growing season is the portion of the year during which environmental conditions permit most crop growth. In temperate climates this period runs from the last spring frost to the first autumn frost, and its length varies with latitude, altitude, and local weather patterns. In tropical and subtropical regions, the growing season can be year-round or follow pronounced wet and dry seasons.

Key factors include air and soil temperatures, soil moisture, daylight hours, and frost risk. Many crops require a minimum soil or air temperature to germinate and develop; cool-season crops tolerate light frost and cool soils, while warm-season crops need longer warm periods. Growing season length is commonly expressed as the number of frost-free days or as growing degree days (GDD), which accumulate daily mean temperatures above a base threshold to estimate crop development and harvest windows.

Measurement and planning: Farmers and gardeners use historical frost dates, weather forecasts, and microclimate data to plan planting, harvest, and succession crops. Microclimates (south-facing exposures, wind protection, proximity to structures) can extend or shorten the season locally.

Season extension and management: Techniques such as row covers, high tunnels, greenhouses, mulching, and irrigation scheduling can extend the usable season and improve yields.

Impact: A longer growing season generally enables more diverse crops and higher yields but may also increase water requirements and pest pressure. Climate change can shift frost dates and pattern variability, altering regional growing season lengths over time.