Jardín de peonías de Tsukuba, Botanical research garden in Tsukuba, Japan.

Tsukuba Peony Garden is a private botanical garden in Tsukuba, Ibaraki Prefecture, growing 550 cultivars of tree peony and 215 of herbaceous peony, more than 50,000 plants in all. Its bowl-shaped grounds hold a pond crossed by a Japanese-style arched bridge, and herons and kingfishers visit the site.

The garden opened in April 1989 as Tsukuba Botan-en, founded by the Kukizaki Tourist Farm. In 2016 that company applied for civil rehabilitation, and since then the garden has been run by the company Leaf. It remains a private botanical garden.

Since 2018 the garden has recreated an English-style garden with herbs and a Peter Rabbit theme, and its restaurant was redecorated after the character. The garden grows peonies and herbaceous peonies without herbicides, letting weeds repel insects, an approach called "grass-growing cultivation".

The garden is open from 9:00 to 17:00, Tuesday to Sunday, and closed on Mondays. Spring admission runs from mid-April to mid-June, with last entry at 16:30; winter hours in January and February are 10:00 to 16:00, last entry 15:30. It is closed in March and from July to December.

The garden grows peonies and herbaceous peonies without herbicides, letting weeds act as natural pest control in a method called sod cultivation. Since 2019 it has tested compost made from horse manure collected around Lake Kasumigaura, reporting larger flowers and longer bloom periods.