Thousands of plants are growing here! Check out the map below, then click the drop-down menus to find out what species are growing in each location. At the bottom of the page, learn about the significance of the landscape and check out our What's In Bloom blog to learn what's blooming at the moment.
Notable landscape features on the Gateway Arch grounds (simplified and abbreviated)
Learn about landscape features
Click the drop-down menus to learn what's planted in each location.
Our most widespread plant is ornamental turf grass, shown as green on the above map. The grass is a hardy and fast-growing fescue blend and covers 74 acres. During the height of the growing season, it needs to be mowed once or twice a week. Keeping the lawn looking its best is a full-time job for at least two people from April to October!
There is a timer-controlled sprinkler irrigation system to supply the grass with all the water it needs, but the watering schedule is flexible depending on rainfall. In Luther Ely Smith Square (below the Old Courthouse on the map above) the grass and all other plants are irrigated with stormwater that is filtered and stored in a 36,000-gallon water retention basin.
Though the grass is reseeded every year – grooves are cut in, then grass seeds are put in the grooves – it doesn’t get stripped and resodded unless something big happens. When one considers the thousands of people who could be walking on the grass on any given day, the resilience and health of our turf grass is remarkable!
The monoculture-lined walking paths (allées) are considered character-defining features of the Gateway Arch’s landscape design. As a contributing feature to a landscape listed on the National Register of Historic Places, The allées are protected under National Register Criteria A and C. Learn more about the significance of this historic cultural landscape here and here.
London Plane Trees are hybrids of Oriental Plane (Platanus orientalis) and American sycamore (Plantanus occidentalis). Ours are Bloodgood cultivars, which are known for their tolerance of urban conditions. Because they are non-native, the trees are not part of many food webs, though some bird species have been observed snacking on the seed pods.
It will probably take at least 15-20 years for the trees to reach their full height, which could be from 70-100 feet tall. Because the allées are tightly spaced and therefore subjected to shaded and crowded conditions, it is more likely that the London Plane Trees will be on the shorter end of that height estimate. They are unlikely to grow as large as the species could in a more open location.
The trees were fertilized and irrigated when they were first planted, but after they reached around three years of age and had developed a robust root system the irrigation was halted. Now, all the irrigation they receive is rainwater and overspray from the irrigation of the turf grass. So far, they appear to be in excellent health.
The Baldcypress (sometimes spelled Bald Cypress) trees on the arch grounds are some of the oldest in the landscape; some of them were planted prior to 1980. Though there are beautiful mature Baldcypress trees in several locations throughout the arch grounds, they are easiest to find in the Baldcypress circles (the red circles to the on the left and right upper corners of the map above).
Baldcypress is a stellar tree for this area. They have performed very well here, with minimal insect and disease issues. The tree can handle polluted air, flooding, and intense drought. They have even thrived amongst the concrete of Leonor K. Sullivan boulevard. The only Baldcypress on the grounds that has ever needed to be removed was struck by lightning and did not bounce back afterwards. The trees receive no special treatment.
Because Baldcypress are deciduous trees, they do drop their needles every fall. If you notice the needles turning red or falling off, don’t be alarmed.
Visitors are invited to walk inside the Baldcypress circles during their visit. The clearing surrounded by evenly spaced tall trees provides peace and tranquility in a very urban setting.
These small hideaways, lined with grey gravel, provide visitors with a tranquil place to sit and relax. The two zen gardens in Luther Ely Smith Square (just below the Old Courthouse on the map above) are heavily shaded, providing comfortable respite during the summer heat, and have four square rock structures each for visitors to sit on. The two gardens just north and south of the park's entrance are smaller, with one rock seating structure each. Visitors are encouraged to stop by the zen gardens to picnic, journal, do some stretching, or simply to rest.
Our native meadow is almost 3 acres and consists of mostly Big Bluestem and Little Bluestem.
The meadow is meant to resemble a native prairie similar to what existed here prior to European settlement. However, here in our very urban built setting, it requires a lot of upkeep to stay healthy. Gardeners must remove unwanted plants regularly. Since so many nearby non-native plant species spread their seeds by wind or birds, new weeds are constantly sprouting up, especially Johnson grass and cattails. Flooding is also a management concern here. When the bottom section of the prairie floods, unwanted seeds are deposited and grass is killed by being submerged in water.
The meadow is mowed once in the late spring, around April. It’s mowed at that time so ground-nesting birds can finish fledging their young prior to disturbance. If the meadow were located in a rural setting, burning would be preferred, but due to its proximity to important city infrastructure, mowing is safer and easier while still being highly effective.
Below is a list of dominant plants in the meadow: Panicum virgatum (Switchgrass) Schizachyrium Scoparium (Little Bluestem) Andropogon Gerardi (Big Bluestem) Sporobolus Heterolepis (Prairie Drop Seed) Bouteloua Curtipendula (Sideoats Grama)
Our What's In Bloom blog, updated every 2 weeks in the growing season, includes pictures of anything currently putting on a show in the meadow.
Until 2015, the north end of the park was dominated by a concrete parking garage. This garage was removed as part of the CityArchRiver renovation project to remove barriers between attractions in the downtown area and to incorporate more green space. Studies had also shown that there was ample parking (more than 2,000 spots!) downtown within a five-minute walk of the Arch. The soil under the garage was heavily compacted, but our talented gardeners were able to bring nature back into the space. The former parking garage is now the Explorers’ Garden and native meadow, as well as turf grass and pedestrian walkways.
The Explorers' Garden was planted with the intention of creating space for native pollinators. As such, most plants are native. The goal is to have plants to support insects throughout every season of their life cycle. There should always be something in bloom throughout the entire growing season. The garden is not as highly manicured as other built landscapes on the Arch grounds. For example, dead brush is left standing all winter to provide food and shelter for pollinators instead of being immediately pruned back for aesthetics.
Since the Explorers’ Garden is made of perennials, the boundaries between plantings change year by year as certain species drop their seeds and migrate slightly. As such, it’s impossible to create a map showing precisely where each species is located. However, below is a plant list of species located in the garden.
Our What's In Bloom blog, updated every 2 weeks in the growing season, includes pictures of anything currently putting on a show in the Explorers' Garden.
What does the landscape mean?
"I see architecture not as the building alone, but the building in relation to its surroundings, whether nature or man-made surroundings. I believe very strongly that the single building must be carefully related to the whole in the outdoor space it creates. In its mass and scale and material it must become an enhancing element in the total environment."
Eero Saarinen, architect for the Gateway Arch
From the earliest stages of planning for the Gateway Arch structure, the landscape surrounding the Arch has been an important consideration. The landscape around the Arch was designed in tandem with the monument by esteemed landscape architect Dan Kiley, who collaborated with Saarinen on many of his architectural projects.
Since 1987, the Gateway Arch and its surrounding grounds have been protected as a National Historic Landmark. The grounds are considered a premiere example of mid-century modern landscape architecture. The memorial is also listed on the National Register of Historic Places.
Because of the National Historic Landmark designation, the grounds are maintained in their original design as much as possible. The main walking/biking paths are lined with a monoculture of modest, shapely trees; the huge open expanse under the arch is composed of a hardy blend of regularly mowed fescue grasses; the gardens are carefully tended by dedicated professionals. Though it is unusual for a national park to have no natural plant life, Gateway Arch National Park’s preservation of the historic cultural landscape does support the mission of the National Park Service: to protect and preserve both natural and cultural resources.