The
Three Sisters are the three main agricultural crops of some
Native AmericanThe indigenous peoples of the Americas are the pre-Columbian inhabitants of the Americas, their descendants, and many ethnic groups who identify with those peoples...
groups in
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
: squash,
maizeMaize , is a herbaceous plant domesticated in Mesoamerica and subsequently spread throughout the American continents...
, and climbing
beanBean is a common name for large plant seeds of several genera of the family Fabaceae used for human food or animal feed....
s (typically
tepary beanThe Tepary bean is native to the southwestern United States and Mexico and has been grown there by the native peoples since pre-Columbian times. It is more drought-resistant than the common bean and is grown in desert and semi-desert conditions from Arizona through Mexico to Costa Rica...
s or
common beanThe common bean, Phaseolus vulgaris, is an herbaceous annual plant domesticated independently in ancient Mesoamerica and the Andes, and now grown worldwide for its edible bean, popular both dry and as a green bean. The leaf is occasionally used as a leaf vegetable, and the straw is used for fodder....
s).
In one technique known as
companion plantingCompanion planting is the planting of different crops in close physical proximity , on the theory that they assist each other in nutrient uptake, pest control, pollination, and other factors necessary to increasing crop productivity.Although there is a wealth of information on its historic use,...
, the three crops are planted close together. Flat-topped mounds of soil are built for each cluster of crops. Each mound is about 30 cm (1 ft) high and 50 cm (20 in) wide, and several maize seeds are
plantedSowing is the process of planting seeds.However, before sowing, good quality seeds should be selected to produce a high yield.-Pre-treatment of seed and soil before sowing:...
close together in the center of each mound.
The
Three Sisters are the three main agricultural crops of some
Native AmericanThe indigenous peoples of the Americas are the pre-Columbian inhabitants of the Americas, their descendants, and many ethnic groups who identify with those peoples...
groups in
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
: squash,
maizeMaize , is a herbaceous plant domesticated in Mesoamerica and subsequently spread throughout the American continents...
, and climbing
beanBean is a common name for large plant seeds of several genera of the family Fabaceae used for human food or animal feed....
s (typically
tepary beanThe Tepary bean is native to the southwestern United States and Mexico and has been grown there by the native peoples since pre-Columbian times. It is more drought-resistant than the common bean and is grown in desert and semi-desert conditions from Arizona through Mexico to Costa Rica...
s or
common beanThe common bean, Phaseolus vulgaris, is an herbaceous annual plant domesticated independently in ancient Mesoamerica and the Andes, and now grown worldwide for its edible bean, popular both dry and as a green bean. The leaf is occasionally used as a leaf vegetable, and the straw is used for fodder....
s).
In one technique known as
companion plantingCompanion planting is the planting of different crops in close physical proximity , on the theory that they assist each other in nutrient uptake, pest control, pollination, and other factors necessary to increasing crop productivity.Although there is a wealth of information on its historic use,...
, the three crops are planted close together. Flat-topped mounds of soil are built for each cluster of crops. Each mound is about 30 cm (1 ft) high and 50 cm (20 in) wide, and several maize seeds are
plantedSowing is the process of planting seeds.However, before sowing, good quality seeds should be selected to produce a high yield.-Pre-treatment of seed and soil before sowing:...
close together in the center of each mound. In parts of the
Atlantic NortheastThe Atlantic Northeast is a region of North America, comprising New England in the United States and the Maritimes in Canada. Definitions of the region vary; in New England it may be restricted to the rural north, and it may also extend to all of Atlantic Canada.The region is noted for a cultural...
, rotten fish or eel are buried in the mound with the maize seeds, to act as additional fertilizer where the soil is poor. When the maize is 15 cm (6 inches) tall, beans and squash are planted around the maize, alternating between beans and squash.
MilpaMilpa is a crop-growing system used throughout Mesoamerica. It has been most extensively described in the Yucatán peninsula area of Mexico. The word milpa is a Mexican Spanish term meaning "field," and is derived from the Nahuatl word phrase mil-pa "to the field"...
s are farms or gardens that employ companion planting on a larger scale.
The three crops benefit from each other. The maize provides a structure for the beans to climb, eliminating the need for poles. The beans provide the
nitrogenNitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere.Many industrially important...
to the
soilSoil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics. It is composed of particles of broken rock that have been altered by chemical and...
that the other plants utilize and the squash spreads along the ground, monopolizing the
sunlightSunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the...
to prevent
weedA weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-made settings such as gardens, lawns or agricultural areas, but also in parks, woods and other natural areas. More specifically, the term is often...
s. The squash leaves act as a "living
mulchIn agriculture and gardening, is a protective cover placed over the soil, primarily to modify the effects of the local climate. A wide variety of natural and synthetic materials are used.- Purposes :...
," creating a
microclimateA microclimate is a local atmospheric zone where the climate differs from the surrounding area. The term may refer to areas as small as a few square feet or as large as many square miles...
to retain moisture in the soil, and the
prickly hairs of the vine deter pests. Maize lacks the
amino acidAmino acids are molecules containing an amine group, a carboxylic acid group and one of the twenty R-groups. These molecules are particularly important in biochemistry, where this term refers to alpha-amino acids with the general formula H
2NCHRCOOH, where R is an organic substituent...
s
lysineLysine is an α-amino acid with the chemical formula HO
2CCH
4NH
2. This amino acid is an essential amino acid, which means that humans cannot synthesize it. Its codons are AAA and AAG.Lysine is a base, as are arginine and histidine...
and
tryptophanTryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
, which the body needs to make
proteinProteins are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues...
s and
niacinNiacin, also known as vitamin B
3 or nicotinic acid, is a water-soluble vitamin. It is an organic compound with the molecular formula C
6H
5NO
2. It is a derivative of pyridine, with a carboxyl group at the 3-position...
, but beans contain both and therefore together they provide a balanced diet.
Native Americans throughout North America are known for growing variations of three sisters gardens. The Anasazi are known for adopting this garden design in a more xeric environment. The
TewaThe Tewa are a linguistic group of Pueblo American Indians who speak the Tewa language and share the Pueblo culture. Their homelands are on or near the Rio Grande in New Mexico north of Santa Fe...
and other Southwest tribes often included a "fourth sister" known as "Rocky Mountain bee plant" (
Cleome serrulata), which attracts bees to help pollinate the beans and squash.
The three sisters planting method is featured on the 2009 reverse of new issues of the US
Sacagawea dollarThe Sacagawea dollar, along with the Presidential Dollar series, is one of the two current United States dollar coins. This coin was first minted by the United States Mint in 2000 and depicts the Shoshone woman Sacagawea, a member of the Lewis and Clark Expedition, carrying her son Jean Baptiste...
coin.
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