Visitors of Allen Centennial Garden know it packs a punch. On just 2.5 acres of land, we proudly feature 27 different styles of gardening. Most of these gardens feature perennials for ease of maintenance and cost-saving. However, 2 of the 27 gardens at Allen Garden are annual display gardens, featuring a rotating spectacle of showy flowering annuals. The plants that are selected for the annual display in these gardens are inspired by an annual theme, this year being “Illuminate the Garden.” The two gardens displaying the annual theme are the Corner Garden at the intersection of Babcock Dr and Observatory Dr, and the Orientation garden, the first garden that welcomes you when you walk through the gates. The 2026 theme will not only guide the physical plantings and signage in the garden, its threads will also be found as we work to further illuminate the mission of the garden. Thus, this theme highlights metaphorical interpretations of illumination, as well as literal relationships with light.

It goes without saying that plants have an extensive relationship with light. Sunlight is the primary source of energy for plants, where the process of photosynthesis converts sunlight into sugars as a fuel source for plants. Plants are influenced by intensity, duration, and types of light. For instance blue light stimulates growth, while red light promotes flower production. The duration of sunlight, or photoperiodism, acts as a seasonal signal to plants indicating when to flower, or break dormancy, or drop leaves. The sun is the powerhouse of energy and lifecycles.

When the sun sets and the moon begins to rise, a whole other relationship to light comes to life. While moonlight is not strong enough for photosynthesis, the gravitational pull of the moon is known to affect water and tides, as well as moisture in the soil. During New and Full Moons, the gravitational pull brings water to the soil surface, which can help seeds germinate faster. There are indications that the moon also affects the flow of water within plants, translating to interactions with sap flow. It is also thought that the gravity of the moon may have an influence on geotropism, which is how plants interact with gravity – sending roots down and shoots up, even if they lay on their sides. There is a growing body of research indicating lunar influence on plants that is also substantiated by an extensive history of lunar based agriculture, where many cultures across time base planting, pruning, and harvesting on the phases of the moon.

To represent the physical relationships between plants and light, I chose to create a Sun Garden in the Corner Garden, and a Moon Garden in the Orientation Garden. The Sun Garden matches the warmth of the sun with a colorful display of warm hues in flowers and foliage. Yellow and orange gazanias, red penutias, crimson coleus, yellow celosia, orange vermillionaire, mixed dahlias, cannas, and sunflowers compose the spread of chosen plants. The sunflower of course found its place in the mix not only because their ray-like petals mimic sunrays, but sunflowers also exhibit heliotropism, a phenomenon where flowers actively follow the sun across the sky from east to west to maximize absorption of the light.

The Orientation Garden features a moon garden, which is meant to come alive at night. Plants with silvery foliage and white flowers softly illuminate and reflect moonlight. Plants with contrasting dark foliage make these flowers sparkle like stars in the night sky. Several plants also boast flowers that bloom at dusk, where nighttime pollinators like moths and beetles find their feast. These nighttime bloomers include Missouri Evening Primrose, and Moonflower. Several plants sporting white flowers include cosmos, dahlias, angelonia, alyssum, and euphorbia, while silver foliage is brought by Dusty Miller, and Dichondria Silver Surfer. Heuchera “Timeless Night” and Penstemon “Onyx and Pearls” bear the contrasting dark foliage to accentuate the white blooms at night. This display will also feature a guilty pleasure purchase – a bioluminescent petunia that will quite literally glow at night. This is the world’s first bioluminescent plant that will bloom white during the day and emit an ethereal glow throughout the night. This garden highlights that while gardens may feel quieter at night, its activity doesn’t die down quite as much as we expect.

Open dawn to dusk, we invite you to visit the garden in full energy during the day, but also to take a serene evening stroll as the day winds down to watch nighttime activities and blooms emerge.