How Seed Banks Work

An Australian wheat farmer examines his crop, which has been weakened by drought. See more vegetable pictures.
An Australian wheat farmer examines his crop, which has been weakened by drought. See more vegetable pictures.
William West/AFP/Getty Images

Plants are crucial for the welfare of human society. They help our ecosystem function. They provide us with oxygen to breath, medicine, clothing fiber and, importantly, food. Out of the 7,000 species of plants currently used for agriculture around the planet, only 30 crops make up the world's diet. Wheat, corn and rice alone account for more than half of the world's food consumption [source: Diverseeds].

Did you ever stop to think about what might happen if these crops disappeared? Right now, for example, our wheat supply is dwindling. The world's stockpiles are at their lowest numbers in thirty years. Consumption is exceeding production, and farmers are having a tough time keeping up. Experts predict this trend is temporary [source: Streitfeld].


But what if it's not? Or, what if a natural disaster wipes out the majority of wheat and other important crops? Scientists think they have hit upon a solution -- seed banks.

Think of a seed bank as a savings account. Seeds are "deposited" into secure storage with the intention of "withdrawing" them in the future when they are needed. Just as you might keep money saved for an unforeseen emergency, scientists are saving up seeds to use for replanting in case certain crops die out or are destroyed. When stored correctly, seeds can remain viable for decades or even centuries [source: Minister of Agriculture and Food].

There are currently about 1,400 seed banks around the world, but the most famous is the Svalbard Global Seed Vault, which opened on Feb. 26, 2008. Also known as the Doomsday Vault, it functions as a global repository and backup for all other seed banks [source: Mellgren].

Seed banking is a complicated concept. This article will touch upon all of its facets -- why we need seed banks, who's responsible for the seeds, and how they are stored. Read on to find out why seed banking is an investment in the future of the human race.


Why are seed banks necessary?

A farmer passes his hand over corn. Corn comes in many different varieties, depending on climate and region.
A farmer passes his hand over corn. Corn comes in many different varieties, depending on climate and region.
China Photos/Stringer/Getty Images

Although you might think the concept is rooted in the contemporary "green" movement, seed banking is not a new phenomenon. Scientists believe agriculture began as far back as 8000 B.C., in the mountains of Mesopotamia, now present day Iraq. Even then, farmers realized their seeds needed protection in order to ensure the next year's harvest. As a result, seed harvesting was one of the most important rituals in ancient farming communities. In Iraq, scientists have discovered evidence of seed banks from as far back as 6750 B.C. [source: Seabrook].

Back then, seed banks protected seeds from animals and extreme weather. Today, we store seeds for different reasons. The most essential reason is crop diversity. Just as humans have specific genetic traits, so do plants. And just as humans have evolved and adapted to specific conditions over time, so have plants. Different varieties of plants are suited for different things. A good example is corn. Corn is grown in different parts of the world and in different climates, which creates many varieties of corn [source: Rosenthal].


­This sort of diversity must be preserved -- not because we need 50 varieties of popcorn, but because we don't want to lose any plants that may prove valuable in the future. For example, in the 1970s a widespread fungus cut United States corn yields in half. The blight was alleviated by use of genetic materials from a wild corn relative that was fungus-resistant [source: WWF].

Aside from crop diversity, there are many other reasons we need to store and preserve seeds:

  • Climate change: Scientists are concerned that climate change will cause extreme weather conditions and bring new pests into some environments. These events could cause certain species of plants to go extinct [source: Rosenthal].
  • Natural disasters: Natural disasters can wreak havoc on a region's ecosystem. After the 2004 tsunami destroyed rice paddies in Malaysia and Sri Lanka, international seed banks provided local farmers with varieties of rice to begin growing their crops again [source: Roug].
  • Disease: Disease quickly and easily wipes out crops. For example, a recent strain of disease called stem rust (Ug99) may have the capability to infect up to 25 percent of the world's wheat supply [source: Singh].
  • Man-made disaster: Man-made disasters can be as devastating to plant life as natural disasters. An obvious example would be war. In fact, one of Iraq's vital seed banks was looted during fighting [source: Pearce].
  • Research: Indigenous people have used plants to cure sickness for centuries. One in every six wild plants is used for medicinal purposes [source: Levine]. Who knows what diseases the right plant or herb could eradicate?

Now that we understand why seed banks are necessary, let's learn which seeds get banked. Are all plants guaranteed a spot in the seed bank or are some deliberately shunned? Read the next page to find out.

What seeds are stored in banks?

A person holds seeds in a soy bean field.
A person holds seeds in a soy bean field.
Domino/Getty Images

A seed bank is only as good as the seeds it houses. Our planet hosts millions of varieties of plant species. Who decides which types of seeds should be stored? All of them? Only the "best" ones? How deep is this library of seeds?

There are about 1,400 seed banks around the world, so which seeds get chosen for storage varies from location to location. Local seed banks may focus on the storage of indigenous wildflowers or specialty vegetables, for example. Other banks have a more global focus. For example, the Global Crop Diversity Trust concentrates solely on a selection of priority crops determined to be the most globally beneficial. These crops include but are not limited to the following:


  • Apple
  • Banana
  • Barley
  • Bean
  • Carrot
  • Coconut
  • Eggplant
  • Lentil
  • Maize
  • Oat
  • Pea
  • Potato
  • Rice
  • Strawberry
  • Sweet potato
  • Wheat

[source: Global Crop Diversity Trust]

The Global Diversity Crop Trust works within the framework of a treaty intended to help conserve crop diversity worldwide. This treaty -- The International Treaty on Plant Genetic Resources for Food and Agriculture (PGRFA) -- was ratified by 40 governments in 2004 and established a global system to provide farmers, plant breeders and scientists with access to plant genetic materials, such as seeds [source: PGRFA].

The PGRFA permits access to these seeds for the purposes of research or agriculture, as long as the results are beneficial to all. Under the authority of the treaty, the Consultative Group on International Agricultural Research (CGIAR) holds the collections [source: CGIAR]. The reason all these organizations are necessary is that the task of managing seeds from every single country in the world is a daunting one. But crop diversity cannot be properly maintained unless seeds and plants are collected from different regions.

At these local and international seed banks, do the poisonous plants get a spot? The answer is "yes." Although it may seem dangerous to bank the seeds of poisonous or invasive plants, there's always the possibility of undiscovered uses for a plant. Kudzu, for example, is considered to be one of the most invasive and destructive plants in the southern United States. However, some researchers are starting to look into the feasibility of using kudzu as a biofuel. Is it possible this rapid-growing vine could one day provide clean fuel for our cars? Only time will tell [source: Gjerstad].

Now that we know what types of seeds are stored, let's learn how they are stored and at what temperatures.


How are seeds stored in banks?

Seed collection, organization and storage will vary by seed bank facility. Let's take a look at how one facility manages its library of seeds to get a taste of how it's done. The following steps display how the Department of Environment and Conservation, a local organization in Australia, banks its seeds:

  • First, researchers decide what seeds to collect. Generally, they give priority to threatened plants.
  • After plants are located, seed collection begins. Seeds are most viable for collection and storage when ripe. In the case of fruits, most release their seeds when ripe. However, some plants will retain their seeds for extended periods, which allows a longer collection time. Other plants might seed irregularly, and thus require repeat visits.
  • Researchers collect the seeds manually with tweezers, pole cutters, seed traps or nets and buckets, depending on the type of plant.
  • For each collection, they record details like location, plant description, habitat, soil type and other information. This information provides data about the local plant population and ensures optimal replanting conditions.
  • Collectors then assign each sample a unique number.
  • Collectors clean each sample to ensure high quality. Seeds can be cleaned by shaking them through a sieve or with a machine that blows air on them.
  • To reduce the moisture content of the seeds, collectors dry them in a temperature- and humidity-controlled room. Afterwards, they place the seeds in sealed, airtight containers.
  • The final storage step is to freeze the seeds at minus 4 degrees Fahrenheit (minus 20 degrees Celsius).

[source: Nature Base]


Difficult-to-store seeds may respond better to cryopreservation, or in-vitro storage. For example, the banana plant doesn't produce seeds, so alternative storage methods are necessary. In-vitro storage means that living plant tissues are stored, rather than seeds. Scientists then place these living tissues in liquid nitrogen -- around minus 320 degrees Fahrenheit (minus 196 degrees Celsius) -- to ensure better long-term storage [source: Bioversity International].

­Although shelf life varies from crop to crop, most seeds can survive in cold storage for decades and some even longer. Eventually, though, all seeds will die. Before this happens, scientists remove seeds from storage and plant them to harvest and re-bank fresh seeds.

With all these seeds in storage, who gets ownership of the seeds? Usually the owners of the seed banks control their own seeds. But in the case of the Svalbard Vault in Norway, depositors retain possession rights of the seeds they place in the bank [source: Svalbard FAQ]. Of course, these ownership rights don't preclude one country lending seeds to another country in need.

Next, we will take a closer look at the "Doomsday Vault," along with other seed bank facilities around the world. ­

Seed Banks Around the World

An employee at the International Rice Research Institute (IRRI) sorts out rice seeds prior to deep freeze storage at the IRRI rice germplasm bank in Laguna.
An employee at the International Rice Research Institute (IRRI) sorts out rice seeds prior to deep freeze storage at the IRRI rice germplasm bank in Laguna.
Joel Nito/AFP/Getty Images

As stated earlier, there are more than 1,000 seed banks located all over the world. We obviously don't have the time or space to discuss each one here, so let's focus on a few of the major facilities.

The Svalbard International Seed Vault, also known as the Doomsday Vault, opened for storage in February 2008. It is located deep in the side of a frozen arctic mountain in Longyearbyen, Norway, and can weather any disaster from bombings to earthquakes. The Global Crop Diversity Trust and the Consultative Group on International Agricultural Research (CGIAR) worked together to collect and organize samples from seed banks all over the world to be stored in the underground vault. Researchers chose its location -- remote yet accessible -- because of its climate and geology, both of which are optimal for cold storage [source: Fowler].


Rather than acting as an active seed repository, the Doomsday Vault is a global backup system for the planet's plant resources. The seeds in the vault are stored under "black box" arrangements, meaning that overseers of the vault will never open or test any of the seed packages. In fact, security is so tight that no single person possesses all the codes necessary to enter the vault [source: Rosenthal]. The responsibility for replacements and additions lies solely with the organization that provided the seeds in the first place [source: Global Crop Diversity Trust]. All major banks have contributed seeds, including all banks operated by CGIAR [source: Svalbard FAQ].

The Norwegian government funded the construction of the vault, and the Global Crop Diversity Trust is responsible for the annual operating costs [source: Svalbard FAQ].

The Millennium Seed Bank Project (MSBP) is located at the Royal Botanical Gardens, Kew, United Kingdom. Its goal is to eventually store and protect more than 24,000 global species of plants. It currently stores samples of the country's entire native plant population, including several hundred endangered species [source: Millennium Seed Bank Project Fact Sheet]. The MSBP collaborates with other seed banking organizations around the globe by sharing information or assisting in seed collection. Seeds remain in their country of origin, but the Kew location stores duplicates for backup [source: MSBP].

Public and corporate donations, as well as grants and endowments, fund the MSBP [source: MSBP].

The Vavilov Institute of Plant Industry was established in 1894 in St. Petersburg, Russia, and is the oldest seed bank in the world. Nikolai Vavilov, for whom the institute is named, was a Russian biologist and plant breeder. Vavilov was one of the first scientists to understand the importance of crop diversity and played a major role in raising awareness of the importance of genetic conservation. The institute is the only facility of its kind in Russia. Its global collection contains hundreds of thousands of specimens [source: VIR].

The institute has recently been in need of funding and has received grants in the past from the Global Crop Diversity Trust [source: Global Crop Diversity Trust].

Here is a sampling of other seed banks around the world:

  • Berry Botanic Garden (Portland, Ore.): Seeds from endangered plants of the Pacific Northwest
  • International Center for Tropical Agriculture (Coli, Colombia): Cassava, forages, beans
  • International Potato Center (Lima, Peru): Potatoes
  • International Institute for Tropical Agriculture (Ibadan, Nigeria): Groundnut, cowpea, soybean, yam
  • International Rice Research Institute (Los Banos, Philippines): Rice

[source: CGIAR]

For more information on seed banks and other topics related to plants and farming, read the links on the next page.

Lots More Information

Related HowStuffWorks Articles

More Great Links

  • Bioversity International. "Genebanks." 2008. (April 4, 2008)
  • Consultative Group on International Agricultural Research. "Genebanks and Databases - Accessions." 2002. (April 1, 2008)
  • Consultative Group on International Agricultural Research. "Genebanks and Databases." 2005. (April 8, 2008)
  • Diverseeds. "Main Goals." 2008. (March 25, 2008)
  • Fowler, Cary. "Mud, Blood and Genes." Global Crop Diversity Trust. 2006. (March 29, 2008)
  • Gjerstad, D.H.; et al. "The Potential Use of Kudzu as a Biofuel [Abstract]." Oct. 24, 2006. (April 4, 2008)
  • Global Diversity Crop Trust. "Arctic Seed Vault." 2006. (April 1, 2008).
  • Global Diversity Crop Trust. "How is Diversity Conserved?" 2008. (April 8, 2008).
  • Global Diversity Crop Trust. "Priority Crops." 2008. (April 1, 2008).
  • Global Diversity Crop Trust. "Trust Grants." 2008. (April 8, 2008).
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