BOISE, ID – September 9, 2025 — The Idaho Botanical Garden has officially broken ground on the first phase of its 10-acre expansion project.
The expansion will unfold in three stages, covering 10 acres at a time — eventually updating the entire 32-acre stretch of land. The first phase is expected for completion by summer 2026. Once finished, work will continue on the following sections until the full master plan is complete — expected to be complete within three to five years depending on fundraising efforts.
Located in southeast Boise next to the Old Idaho Penitentiary, the Idaho Botanical Garden is a nonprofit living museum. It features a wide variety of carefully selected plants and gardens that are “suitable for Intermountain West landscapes,” according to its website.
The garden also provides a community space for environmental education and workshops on topics such as horticulture, science, technology, engineering, art, math, and meditation. Additionally, it’s home to the Outlaw Field Concert Series, which brings in top-flight live music performances throughout the summer.
The project has been in the planning stages for over five years, beginning with the development of a master plan for the Idaho Botanical Garden in 2020.
The first 10-acre expansion includes infrastructure and underground utility upgrades, expanded parking in the new “parking garden,” a new event lawn and the Borbonus Family Arboretum.
“Why are we doing this? We need the space and the community needs more access to our resources,” Anderson said.
The cost of Phase 1 is estimated to be more than $15 million. To date, over $6 million has been raised through 115 contributions to the garden’s Community Grows Here campaign — allowing for the start of construction.
Officials said that continued public support will be essential to reach the ultimate goal to lay the foundation for future growth phases.
“You (Idaho Botanical Garden) provide green spaces, educational opportunities and a chance for folks to connect in nature to this place and to each other. It’s such an important and integral part of what makes Boise, Boise,” Mayor Lauren McLean said.
“You can’t be in Idaho if you don’t appreciate the community and the outdoors. The Idaho Botanical Garden really exemplifies both of those and we’re really excited about what they’re doing here with the expansion,” said Mark Ruszczyk, Regence BlueShield of Idaho president.
The arboretum will feature a wide variety of tree species designed for a space where visitors can learn, explore and connect with nature. It also aligns with the garden’s recent recognition as an official arboretum.
In April, the Idaho Botanical Garden earned accreditation from ArbNet, a global organization that honors tree-focused gardens. This new designation opens the door to even more opportunities for the garden to grow its resources for the community and puts Boise’s garden on the national map, according to Anderson.
“This arboretum will become a living legacy, a place where future generations can learn, explore and connect with nature right here at the garden,” Senior Director of Development for the Garden Jennifer Parks said.
Anderson said the arboretum will be developed as an interpretive area for educational purposes to help community members learn which tree species are important and thrive in the Treasure Valley — putting a real meaning behind the city of trees.
“It’s more than new garden spaces. It’s about carrying forward our mission to connect people, plans and nature — something that has been incredibly vital to us here at the garden,” Anderson said.
A 22,000-square-foot visitor and education center is also planned, which will hold administrative offices, a store, a cafe and more.
The Boise Farmers Market will also establish a permanent year-round home at the Garden, after jumping around to a handful of different locations over the past few years. Its new home will help expand food access, support local growers and strengthen the connection between urban and agricultural communities.
“Our community is growing at such a significant pace that not only is our population growing, but the needs of our community is growing as well. This first phase of a 10-acre expansion project has quite a few important and vital components,” Anderson said.
Community members looking to donate to the Idaho Botanical Garden’s master expansion plan can do so by making a donation to the Community Grows Here campaign online at idahobotanicalgarden.org.
Expansion construction is expected to take place behind the scenes and will not disrupt any current garden spaces — which remain open during business hours.
“We’re putting shovels in the ground, and we’re getting started on a project that has been essentially nine years in the making. But looking back over time, it’s really been 40 years in the making for us to be on the map as a botanical garden with a lot of merit here in the intermountain west,” Anderson said.
