The Millennium Seed Bank Partnership (MSBP or MSB), which was once called the Millennium Seed Bank Project, is the largest program in the world for saving plants outside their natural homes. It is managed by the Royal Botanic Gardens, Kew, in the UK. The project began in 1996 after receiving a grant from the Millennium Commission in 1995. It is now located in the Wellcome Trust Millennium Building on the grounds of Wakehurst Place in West Sussex. The goal of the project is to act as an "insurance policy" to protect plants from going extinct in the wild by storing their seeds for future use. The storage areas include large underground frozen vaults that keep the world's largest collection of seeds from wild plant species. Dr. Peter Thompson started the project, and Paul Smith managed it after Roger Smith left. Roger Smith received the OBE in 2000 as part of the Queen's New Year Honours for his work on the project.

Project

Working with other projects around the world, expeditions are sent to collect seeds from plants that grow in dry areas. When possible, these seed collections stay in the country where they were gathered, and extra copies are sent to the Millennium Seed Bank Project (MSBP) for safe storage. Partnerships with countries on every continent help these nations meet global goals, such as the Global Strategy for Plant Conservation and the Millennium Development Goals set by the United Nations Environment Programme.

The seed bank at Kew has changed many times. Before the MSBP was created, a seed bank at Kew was started in 1980 by Peter Thompson. Roger Smith led this earlier bank from 1980 to 2005. After 2005, Paul Smith became the head of the MSBP. The Wellcome Trust Millennium Seed Bank building was designed by the firm Stanton Williams and opened by Prince Charles in 2000. The building has two wings with laboratories and offices, and a large open area for visitors. This space includes an exhibition and windows that show visitors how seeds are cleaned and prepared. Visitors can also see the entrance to underground storage rooms where seeds are kept at −20 °C (−4 °F). In 2001, the MSBP started its international program.

In April 2007, the MSBP stored its one billionth seed, a type of African bamboo called Oxytenanthera abyssinica. In October 2009, the MSBP reached its 10% goal of storing seeds from all wild plant species worldwide by adding a wild banana called Musa itinerans to its vault. As scientists learned more about how many seed-bearing plant species exist, by June 2015, the MSBP had stored seeds from 34,088 wild plant species and 1,980,405,036 seeds. This number represented over 13% of all wild plant species on Earth.

As of 2025, the Millennium Seed Bank stored nearly 2.5 billion seeds, collected from 103,000 groups representing over 40,000 species. More than 98% of plant species in the UK that can be stored in seed banks are included in these collections.

Aims

The main goals of the project are to:

• Gather seeds from 75,000 types of plants by 2020. This number is 25% of all known plant species. This is the second step in the project. The first goal, which was to store seeds from 10% of all known plant species by 2010, was completed in October 2009.
• Collect seeds from every plant that grows naturally in the United Kingdom.
• Study ways to protect and keep seeds and plants safe.
• Serve as a central place for research on this topic and help people learn about and support this work.

International partnerships

There are more than 100 partnerships around the world, including Australia, Mexico, Chile, Kenya, China, United States, Jordan, Mali, Malawi, Madagascar, Burkina Faso, Botswana, Tanzania, Saudi Arabia, Lebanon, and South Africa. Australia is especially important because its plant life makes up 15% of the world’s total plant species, and 22% of these plants are at risk of disappearing. Between 2005 and 2009, MSBP led the EU project ENSCONET.

Preservation of seeds

Seed collections arrive at the MSBP in different conditions. Sometimes, they are still attached to fruits, and other times, they are already clean. Each collection usually includes a sample that helps identify the plant. After arrival, the seeds are moved to a dry room where they are stored at 18°C with 15% humidity. Seeds can stay in this room for two weeks to six months, which helps increase their lifespan up to 40 times. Next, the seeds are cleaned of dirt and other plant material, X-rayed to check for pests, and dried again before being sent to the vaults. In the vaults, they are stored at −20°C (−4°F).

Seeds are placed in airtight glass containers with silica gel packets that change color if moisture enters the container. Shortly after storage, seeds are tested to see if they can grow, and then tested again every 10 years. If seed numbers are low, scientists prefer to collect more seeds from plants in the wild.

For some plants that cannot survive standard drying, researchers are testing a method called cryopreservation. This process uses liquid nitrogen to quickly dry and freeze seeds or parts of seeds.

Seed distribution

When seeds are needed for research, they can be asked for from the MSBP's seedlist. If the MSB has the right to do so, it can give up to 60 seeds for free to legitimate, non-commercial groups for use in research, restoring habitats, and reintroducing plants. All seeds given to organizations are shared on a non-profit basis, meaning neither side gains money. The MSB also runs the UK Native Seed Hub, which works to help protect and strengthen nature in the UK by providing high-quality seeds from native plants to groups that care for and restore the environment.