season A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's axial tilt, tilted orbit around the Sun. In temperat ...

is a division of the year marked by changes in weather, ecology, and the amount of daylight. The growing season is that portion of the year in which local conditions (i.e. rainfall, temperature, daylight) permit normal

plant growth Important structures in plant development are buds, Shoot (botany), shoots, roots, leaf, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. ...

. While each

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. In other words, a crop is a plant or plant product that is grown for a specific purpose such as food, Fiber, fibre, or fuel. When plants of the same spe ...

has a specific growing season that depends on its genetic

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the p ...

, growing seasons can generally be grouped into macro-environmental classes.

Axial tilt In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbita ...

of the Earth inherently affect growing seasons across the globe.

Geography

Geographic conditions have major impacts on the growing season for any given area. Latitude is one of the major factors in the length of the growing season. The further from the equator one goes, the angle of the Sun gets lower in the sky. Consequently, sunlight is less direct and the low angle of the Sun means that soil takes longer to warm during the spring months, so the growing season begins later. The other factor is altitude, with high elevations having cooler temperatures which shortens the growing season compared with a low-lying area of the same latitude.

Season extension

Locations

North America

The continental United States ranges from 49° north at the US-Canadian border to 25° north at the southern tip of the US-Mexican border. Most populated areas of Canada are below the 55th parallel. North of the 45th parallel, the growing season is generally 4–5 months, beginning in late April or early May and continuing to late September-early October, and is characterized by warm summers and cold winters with heavy snow. South of the 30th parallel, the growing season is year-round in many areas with hot summers and mild winters. Cool season crops such as peas, lettuce, and spinach are planted in fall or late winter, while warm season crops such as beans and corn are planted in late winter to early spring. In the desert Southwest, the growing season effectively runs in winter, from October to April as the summer months are characterized by extreme heat and arid conditions, making it inhospitable for plants not adapted to this environment. Certain crops such as tomatoes and melons originated in subtropical or tropical regions. Consequently, they require hot weather and a growing season of eight months or more. In colder climate areas where they cannot be directly sowed in the ground, these plants are usually started indoors in a greenhouse and transplanted outside in late spring or early summer.

Europe

The

Pyrenees The Pyrenees are a mountain range straddling the border of France and Spain. They extend nearly from their union with the Cantabrian Mountains to Cap de Creus on the Mediterranean coast, reaching a maximum elevation of at the peak of Aneto. ...

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

, and

Southern Carpathians The Southern Carpathians (also known as the Transylvanian Alps; ; ) are a group of mountain ranges located in southern Romania. They cover the part of the Carpathian Mountains located between the Prahova River in the east and the Timiș and ...

effectively divide Europe into two regions.

Southern Europe Southern Europe is also known as Mediterranean Europe, as its geography is marked by the Mediterranean Sea. Definitions of southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, C ...

and the Mediterranean are in general south of the 45th parallel. The growing seasons last six months or more, and the climate is characterized by hot summers and milder winters. Precipitation mainly falls between October and March, while summers are dry. In the extreme south of Europe, the growing season can be year-round. Vegetation on the Mediterranean islands is often evergreen because of the relatively warm winters.

Northern Northern may refer to the following: Geography * North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating ...

and

Central Europe Central Europe is a geographical region of Europe between Eastern Europe, Eastern, Southern Europe, Southern, Western Europe, Western and Northern Europe, Northern Europe. Central Europe is known for its cultural diversity; however, countries in ...

extend north from the 45th parallel past the Arctic Circle. The growing seasons are shorter because of the lower angle of the Sun and generally range from five months to as little as three in the highlands of Scandinavia and Russia. Climate on the Atlantic coast is considerably moderated by humid ocean air, which makes winters comparatively mild, and freezing weather or snow are rare. Because summers are also mild, many heat-loving plants such as

maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...

do not typically grow in

Northwestern Europe Northwestern Europe, or Northwest Europe, is a loosely defined subregion of Europe, overlapping Northern and Western Europe. The term is used in geographic, history, and military contexts. Geographic definitions Geographically, Northwestern ...

. Further inland, winters become considerably colder. Despite the short growing season in parts of

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

and northern

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, the extreme length of daylight during summer (17 hours or more) allows plants to put on significant growth.

Tropics and deserts

In some warm climates, such as the

tropical savanna climate Tropical savanna climate or tropical wet and dry climate is a tropical climate sub-type that corresponds to the Köppen climate classification categories ''Aw'' (for a dry "winter") and ''As'' (for a dry "summer"). The driest month has less than ...

s (''Aw''), the

hot semi-arid climate A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of sem ...

s (''BSh''), the

hot desert climate The desert climate or arid climate (in the Köppen climate classification ''BWh'' and ''BWk'') is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert ...

s (''BWh'') or the

Mediterranean climate A Mediterranean climate ( ), also called a dry summer climate, described by Köppen and Trewartha as ''Cs'', is a temperate climate type that occurs in the lower mid-latitudes (normally 30 to 44 north and south latitude). Such climates typic ...

s (''Cs''), the growing season is limited by the availability of water, with little growth in the dry season. Unlike in cooler climates where snow or soil freezing is a generally insurmountable obstacle to plant growth, it is often possible to greatly extend the growing season in hot climates by

irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

using water from cooler and/or wetter regions. This can in fact go so far as to allow year-round growth in areas that without irrigation could only support

xerophytic A xerophyte () is a species of plant that has adaptations to survive in an environment with little liquid water. Examples of xerophytes include cactus, cacti, pineapple and some gymnosperm plants. The morphology (biology), morphology and physiology ...

plants. In the tropical regions, the growing season can be interrupted by periods of heavy rainfall, called the rainy season. For example, in Colombia, where coffee is grown and can be harvested year-round, they do not see a rainy season. However, in Indonesia, another large coffee-producing area, they experience this rainy season and the growth of the coffee beans is interrupted.

References

{{Authority control Agricultural terminology Horticulture Meteorological quantities Seasons