May 21, 2019

Perennials on Trial By Jasmina Dolce

Mother’s Day has passed, spring is here, and the heat of summer is just around the corner. The 2019 gardening season has begun, and your greenhouses are at their peak.

As the gardening season kicks off, plant trials across the country are getting their plantings ready for evaluation throughout the season. And over the past few years, it’s been apparent that the quantity of perennial in summer trials has increased substantially.

According to GPN columnist Vaughn Fletcher, “This is the culmination of years of breeding and selection, with significant advances in breeding techniques and a focus on interspecific hybrids.”

In the May issue of GPN, Fletcher shares his thoughts on the top perennial performers from his trial visits throughout last summer. “Many of the varieties I selected have been in trials for two or three years,” he says. “These varieties consistently exhibited durability, robust architecture, heat tolerance, stable flower color, disease resistance, long flowering window and floriferousness.”

Has your perennial selection expanded over the past few years? Have you seen a difference in the breeding innovations brought to market?

If you are looking for new perennial selections to add to your lineup, here is a handful of Fletcher’s top picks. To read his full article, click here.

Agastache ‘Morello’
Terra Nova Nurseries

This agastache has been one of the most floriferous and eye-catching varieties in the trials the past two years. The colorful burgundy-rose inflorescences rise impressively above the foliage. It was extremely heat and humidity tolerant, and an excellent pollinator.

Coreopsis ‘Double the Sun’
Kieft Seed

This 2019 introduction is part of Kieft’s first-year flowering perennial program. It flowers two to three weeks earlier than ‘Early Sunrise’, and the flower size is comparable to ‘Sun Kiss’ and larger than ‘Sun Fire’. This variety was uniform and consistent all summer with a tidy, mounded habit.

Echinacea ‘Mooodz Courage’
HilverdaKooij

HilverdaKooij introduced this echinacea series in 2016 and 2017 and followed up with a larger selection in 2018 trials. The entries the past two years have demonstrated outstanding summer performance with high bud and flower count. Courage features a large central disc, magenta recurved flowers and an upright architecture. The series matures at 20 to 24 inches and is hardy to Zone 5.

Leucanthemum ‘Sweet Daisy Birdy’
Dümmen Orange

The Sweet Daisy series is comprised of four varieties. Birdy was impressive with medium, frilly white pedals and a conspicuous yellow center. It began flowering in June in the southern trials and this continued in Michigan and Colorado into late August and early September. The series is first-year flowering and has a uniform growth habit with dark foliage.

Rudbeckia ‘American Gold Rush’
Intrinsic Perennial Gardens

This rudbeckia was introduced in 2018 and was undoubtedly the most floriferous and impactful Black Eyed Susan observed all summer. This new hybrid produces a compact, dome-like habit with a flower canopy unrivaled in rudbeckia varieties. Most importantly, it is resistant to Septoria Leaf Spot and manifested disease-free foliage.

As you visit plant trials this summer, or even conduct your own in-house trials, feel free to share your favorites with me. I’d love to hear from you and compare observations.

— Jasmina