Petunias, Cuphea Among Favorites From University of Wisconsin Trials

Note: Information for this trials report was provided by Janet Hedtcke of the University of Wisconsin’s West Madison Ag Research Station.

2024 was a very wet season, especially early in the season with a lot of severe weather (intensive, pounding rain and strong winds). Rainfall was 1.5x the normal every month from March-July with dewpoints consistently above 60°F and often over 70° F from June to August.

August and September were very dry with high in the mid 80°s. The plants in the trials at the West Madison Agricultural Research Station display garden were slow to grow early on with saturated, soggy soils, but most responded amazingly well despite these damp conditions. We didn’t see many disease issues, and the gardens were stunning in late summer and fall.

This year, 102 plant varieties of annual bedding plants/cut flowers were evaluated for the industry. Cultivars that excelled from the rating/monthly evaluation data are shown in the table below. Petunias always make the list and included ‘Supertunia Vista Bubblegum’, ‘Supertunia Mini Vista Plum Veined’ (new for 2025), and ‘Supertunia Mini Vista Yellow’ from Proven Winners.

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Two new and one older cuphea cultivars also made the top 12 list: ‘Totally Tempted Frosted Violets’ and ‘Totally Tempted Watermelon Wine’, both from Proven Winners and new for 2025, and ‘Vermillionaire’ from Proven Winners. Beyond these top rated cultivars, all the cultivars in the Beacon series of impatiens from PanAmerican Seed were simply stunning in the shade bed.

As another shade plant, I liked PanAmerican Seed’s Begonia ‘DragonWing Pink Bronze Leaf’. It was a beautiful dual-purpose cultivar with a nice complement of foliage and bloom colors as well as a distinctive leaf shape.

Several Angelonia cultivars held vibrant blooms all summer, especially the Angelface series from Proven Winners.

It was difficult to select only two or three top performers as so many options existed. My top three favorites cultivars included Ageratum ‘Monarch Magic’ (Ball FloraPlant), Celosia ‘Kurume New Scarlet’ (American Takii), and Salvia ‘Unplugged White’ (Proven Winners). ‘Monarch Magic’ was filled with more than a dozen monarchs daily the entire season. ‘Unplugged White’ was uniform, clean, and florific. ‘Kurume New Scarlet’ knocked my socks off with its deep intense red colors for foliage and blooms; it lasted in a vase 8 to 12 days.

The biggest challenge this year was the weather as noted above. Unfortunately, none of the coleus in the trials performed well, possibly due to the wet and cool soils early on. Late in the season when it got hot and dry in mid-August, the SolarScape impatiens (PanAmerican Seed) needed to be watered regularly lest they shrivel and die. We used leaf mulch after spring transplanting to offset moisture fluctuations, but by the end of the season it wears thin. We do irrigate with sprinkler pipe but only when conditions are dire. Also rabbit and other varmint pressure was intense as these animals continued to graze on certain plants all season. They really loved Ball FloraPlant’s lobelia ‘Heatopia Dark Blue’, as well as PanAmerican Seed’s sedum ‘Spectabile Spectacular’ which were repeatedly and completely chewed off so we couldn’t get ratings.

Our diverse gardens continue to be highly valued by industry reps and visitors who come to see how plants perform in our region.  Numerous pollinators also find the display gardens a veritable paradise.  Thanks to the national plant trials, The West Madison Agricultural Research Station’s Display Gardens (in Verona, WI) were a special place to be and enjoy in 2024.

Find more 2024 field trials information here.

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