Butterfly House, Gardens on Spring Creek

The Gardens on Spring Creek, Fort Collins' community botanic garden, opened in 2004. The idea of a horticulture center with an environmental focus dated from 1986, and in 1997 voters approved a municipal programme that set aside 2 million dollars for the first phase. The Butterfly House is the heart of the visitor center extension, completed in 2019.

In 2017 a permanent butterfly house was announced, due to open in 2019 in partnership with the Butterfly Pavilion of Westminster, Colorado; an article from that time cites an overall project of 3 million dollars, with 1 million still to be raised, and a 1,700 sq ft conservatory. In 2019 the local chamber of commerce spoke of a 6-million-dollar "transformation" that also covers five acres of new gardens, begun in November 2017: the two amounts do not cover the same scope. Work on the conservatory and the visitor center extension began on 2 January 2019. Elder Construction, the design-build contractor, reports fifteen months of design and construction; Architecture West is listed with it and the city on the project team.

The opening, announced for 16 November 2019, took place that month, and the visitor center's floor area doubled to 9,740 sq ft. The Butterfly Pavilion remains a partner in running the house, but the Gardens stress that the two organisations are separate. In 2024 staff hand-reared caterpillars of three silk moths, Polyphemus, Promethea and Luna, to show to the public. In September 2026 the Gardens announced that the house was closed for roof construction through 25 September and entrusted the butterflies to the Butterfly Pavilion.

The conservatory sits inside the visitor center, in the 2019 extension. Elder Construction describes a 4,500 sq ft addition that brings together the conservatory, a larger lobby, a meeting room and offices, along with a remodel of the existing building while the Gardens' team kept working on site. The conservatory itself measures about 1,500 sq ft (≈ 140 m²) according to the chamber of commerce and the Coloradoan, and 1,700 sq ft according to the Butterfly Pavilion and a 2017 article. The OpenStreetMap outline of the house covers about 135 m², which agrees with the first figure.

The Gardens call it a "true conservatory" with tall ceilings and in-ground planting beds, in which tropical plants grow vigorously even in midwinter; the official page credits Kelly Kellow as garden designer. On a visit shortly before it opened, the Coloradoan described glass walls fogged with steam on a frosty morning, and Wikipedia calls it an all-glass butterfly house.

A 220 sq ft living wall planted with 2,200 annuals, ferns and foliage plants gives the butterflies places to roost. At the west end a purpose-made window shows the chrysalides delivered each week before they emerge. Entry is by timed slot about every fifteen minutes.

The Gardens advertise 400 to 600 North American butterflies and moths flying freely, of a dozen species according to the official page; the Butterfly Pavilion names monarchs, tiger swallowtails, painted ladies, zebra longwings and red admirals. Unlike the Butterfly Pavilion in Westminster, which shows tropical species, the Fort Collins house is devoted to North American species and offers, in the Butterfly Pavilion's words, a burst of summer during Colorado's winter months.

The more than 100 varieties of tropical plants were chosen to provide nectar and roosting sites; rotating displays of orchids and annuals add extra nectar. There are also caterpillar displays, separate enclosures for male and female moths because of their heavy egg-laying, and decaying fruit or sponges soaked in sugar water to feed the adults. Staff take part in citizen-science programmes: the Colorado Butterfly Monitoring Network, Monarch Watch and the Monarch Larva Monitoring Project.

The Butterfly House occupies the visitor center of the Gardens on Spring Creek, 2145 Centre Avenue. Garden admission includes the conservatory, but an entry time must be reserved at guest services, scheduled about every fifteen minutes; the last entry is half an hour before closing. The roof works of September 2026 closed the house, so it is worth checking with the Gardens that it has reopened.

The garden itself covers 12 acres, with prairie and foothills gardens, rose, fragrance and moon gardens and, according to the chamber of commerce, the largest collection of cold-hardy cacti on display in the United States. Seasonal events, among them the plant sale, Pumpkins on Parade and Garden of Lights, mark the year.