Highlights from 2025 Field Trials: Cincinnati Zoo and Botanical Gardens
(Information provided by Kyra Back, Head Gardener / Manager Display Garden Trials & Growing)
View all
The Cincinnati Zoo and Botanical Garden’s plant trials are unique because we trial our plants in a garden setting, and we strive to achieve certain goals. Our goals include improving plant diversity by testing and sharing ideas and lists of top-performing varieties for urban landscapes. Through these efforts, the Zoo fosters greater pollinator and wildlife diversity. We feel this is the best way to help local gardeners and landscapers choose plants that thrive in the region’s conditions while also supporting our local wildlife.
Annual trial plants are supplied by various breeders and growing companies and are installed each May throughout the Zoo’s display gardens and at our offsite trial location at Rockdale Academy Learning Garden. The gardens are maintained by seasonal horticulture staff and volunteers throughout the growing season.
Each plant is clearly labeled and evaluated between July and September by Zoo horticulturists, volunteers, and members of the public. This year, we trialed 893 varieties. Plants are rated on a scale from 1 to 5, where we observe plant vigor and health, ornamental value, urban sustainability, and value to wildlife. The overall purpose of our plant trials is to help the horticulture industry identify resilient, high-performing plants that guide our visitors in selecting species suited to urban gardens, while also providing habitats for pollinators and other wildlife.
Below is a preview of some of this year’s best performers. A complete list of the 2025 Zoo’s Best Annual Plants will be available in early spring at: https://cincinnatizoo.org/gardens/plants/
Climate and Growing Conditions
This year brought intense sun and fluctuating rainfall across the growing season. The first 90°F days arrived earlier than usual in June, and the region experienced 5.6 more days above 90°F than average with high humidity. From late May through July, weather patterns swung between stretches of heavy rain for days in a row, then a week of no rain. Within a single day, conditions could shift from light showers to downpours and storms. Although total rainfall was only about 2 inches above normal, much of it fell in short bursts of 1–3 inches at a time.
August brought relatively normal weather, followed by a brief drought in September.
Despite the unpredictable conditions, overall plant growth was strong. However, some typically reliable performers, like petunias and dahlias, had problems due to unknown causes.
Our biggest challenge was managing water and fertilizer amid erratic rainfall. We trained our team to check irrigation daily as well as keep a sharp eye on fertilization needs.
Standout Performers from the 2025 Trials
Flossflower Ageratum houstonianum Monarch Magic (Ball Floraplant)
Flossflower Ageratum houstonianum Monarch Magic (Ball Floraplant) – A great bloomer and attracts monarchs by the droves!
Summer Snapdragon Angelonia hybrid Angelface White (Proven Winners)
Summer Snapdragon Angelonia hybrid Angelface White (Proven Winners) – This plant put on an amazing show! The Angelface series, in general, seems easy to grow and bloom well all summer without a break.
Lantana Lantana camara Passionfruit (Ball FloraPlant)
Lantana Lantana camara Passionfruit (Ball FloraPlant) – Whereas many of our lantana don’t bloom until it is very hot, this lantana delivered full-covered bloom from June to early October!
Begonia Begonia semperflorens Mega Cool White (Benary)
Begonia Begonia semperflorens Mega Cool White (Benary) – A clean, beautiful compact white begonia that was covered in bees all summer long.
For more 2025 field trials information and variety highlights, click here.
Subscribe to eNewsletter
