Perennial Trends Revealed at CAST
Before I share a few more perennials that were on display at the California Spring Trials in April, I thought I’d pass along an article Bill Calkins wrote on perennial trends he observed at CAST in last week's Tech on Demand newsletter.
Following California Spring Trials 2026, I’ve been reorganizing some notes and our daily newsletter musings into groupings and putting together reports on different trends and segments that stood out to me. I’ll share some of these in the newsletter from time to time. Such as this:
Perennials have been quietly, but decisively, expanding their footprint at California Spring Trials. While annuals have historically been in the spotlight, the past few years have made it clear (at least to me) that perennial breeding is moving just as fast, reaching more markets and solving more production challenges than ever before. Across genera, breeders emphasized first-year flowering, container application, disease resistance, environmental tolerance and retail season extension, all while delivering seasonal color and improved habits for programs.
One of the most important perennial discussion points at CAST 2026 was the continued effort to fit perennials into annuals programs—without losing their hardiness or garden performance. That goal surfaced repeatedly this year in introductions bred for faster finishing, predictable sizing and multi-season appeal. Small, adaptable perennials capable of filling packs, quarts and mixed containers were everywhere, proving that perennials are now embedded in spring retail strategies rather than isolated to summer and fall sales.
That annualization of perennials was especially evident in crops traditionally viewed as landscape only. A standout example was the DayScape series of daylilies (Darwin Perennials), which reflected a fundamental shift in how breeders are positioning classic perennials. The DayScape collection showcased nine colors bred specifically for rust resistance (extremely important below the Mason-Dixon line), but also for first-year flowering, long-lasting blooms, continuous rebloom, compact habit, wet and drought tolerance and more. Unlike traditional daylilies that peak briefly and then recede into foliage, DayScape varieties were selected for extended color display and strong retail presence. The many additional benefits reinforce the idea that daylilies are now legitimate players in spring and early summer container programs.
Broad adaptability was a recurring theme well beyond daylilies. Compact or “petite” perennial varieties were prevalent across the trials, offering growers options that fit modern production realities. Crops such as Lavender Scent Mini Blue (Syngenta/ThinkPlants) illustrated how breeders are shrinking traditionally larger perennials into formats suitable for quarts and smaller patio pots—without sacrificing sensory impact. Despite its smaller size, Scent Mini Blue is all about fragrance and first-year flowering, aligning perfectly with what today’s shoppers are looking for.
Stress tolerance—both heat and cold—was another key message wrapped around perennial breeding at CAST 2026. Exhibitors repeatedly emphasized genetics that perform across regions. In gaillardia (one of my favorite perennials and a crop we’ve seen a bunch of new intros in over the past few years), additions to the Gusto series (Danziger), including Swift Saffron—which has a nice habit and good heat tolerance—meaning it’s expected to have a longer shelf life and better garden performance than other gaillardias. Along similar lines, Heliopsis Forged in Fire has improved mildew resistance, dark stems and heavy branching—all of which lead to grower-friendly production efficiencies and landscape or home garden performance.
Cold hardiness has also been mentioned more and more at CAST for the past few years, showing that breeders are working on behalf of growers serving northern markets and looking to extend shoulder season sales. Several breeders showed us perennials trialed and selected for Zone 3 and 4, even with new varieties touting compact habits and container use. Obviously, these benefits aren’t impacting hardiness, which is nice to see.
Another long-term trend we’ve written about for the better part of a decade (and one that doesn’t seem to be slowing down) is the expanded role of perennials in mixed and combination programs. Several new recipes featured perennials as structural (thriller) elements paired with annual fillers and spillers, creating containers designed to evolve over time rather than peak and go to green. This approach increases perceived value for consumers and positions perennials as multi-season “investments.”
The main thing that stood out to me across all of the perennial introductions at CAST 2026 was that breeders are really focused on what happens after the sale. Disease resistance, long shelf life, limited color fading, reblooming without deadheading and true garden durability were consistently cited as priorities. The message was clear once again: perennials are no longer sold green, dependent on big full-color tags and a promise—they’re being bred for color on the retail bench every season AND performance customers and landscape professionals can actually see and appreciate for months and years.
I think perennials at CAST this year reflected both maturity and momentum. Current breeding efforts aren’t just for niche markets and novelty; we’re seeing plants that are easier to grow, easier to sell and easier to succeed with—across climates, container sizes and retail formats
Bill, you did a very nice job summarizing the current status of the perennial market as it relates to plant genetics and where perennial breeding is heading. Thanks for attending CAST and for sharing your observations.
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CAST Perennial Highlights: Dümmen Orange
Agastache HoneySticks Gold
Gold is a new addition to the floriferous HoneySticks series of agastache. This first-year flowering perennial is early to bloom and continues producing large golden yellow tubular flowers all season long until the first frost.
HoneySticks Gold is an interspecific hybrid, grows 12- to 18-in. tall, has aromatic foliage and has the brightest yellow flowers for this type of agastache currently on the market. Hardy to Zone 4.
Coreopsis Radiant Series
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Radiant Lemon
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Radiant Red
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Radiant is a new series of coreopsis from Dümmen Orange. There are currently three cultivars in the series: Lemon, Red (both shown above) and Orange (not shown). The Radiant series is first-year flowering, grows 12- to 14-in. tall and is hardy to Zone 5.
CAST Perennial Highlights: Syngenta Flowers
Iberis Whistler Late
If you’re familiar with growing iberis, you probably have experienced its extremely early flowering tendency. So early that there are either no customers to purchase them or it blooms before other early blooming perennials are ready for sales, not allowing for a good mix of perennials for the earliest shipping windows.
Syngenta Flowers recent iberis introduction
Whistler Late solves that dilemma and blooms three to four weeks later than its counterparts. This F1 seed cultivar brings exceptional uniformity in both habit and flowering. Excellent branching allows it to fill out like vegetative cultivars do. Whistler Late remains compact (4 to 8 in.) and covers itself with crisp, white flower clusters. Hardy to Zone 3.
Sedum Hot Rocks Dark Leaf Red
Sedum Hot Rocks Dark Leaf Red is a new introduction of upright sedum resulting from contemporary breeding methods. It has dark chocolate foliage and covers itself with pretty pink flowers in the fall. Hot Rocks Dark Leaf Red has a great branched and compact 10- to 14-in. growth habit, which reduces lodging. Hardy to Zone 4.
Sesleria Star Crossed
Sesleria, commonly referred to as Moor Grass, is an under-the-radar durable, cool-season ornamental grass that forms neat clumps of fine textured, often blue-green, foliage. They're highly adaptable to various conditions, including sunny or shady spots or locations with poor soils (including alkaline soils).
Star Crossed is a recent introduction from Intrinsic Perennial Gardens that, to my knowledge, wasn't at CAST, but does deserve a little love and attention. Star Crossed was born from a cross of two exceptional blue forms of sesleria. This new introduction has wider and bluer foliage, forming compact 8- to 10-in. tall by 12-in. wide mounds. It produces numerous creamy yellow flowers held on 15-in. winged stems. Hardy to Zone 5.
Train Your Watering Staff
The University of Florida IFAS Extension has launched a FREE Professional Irrigation training series as part of its Greenhouse Training Program. The irrigation modules are designed to help growers train staff to avoid overwatering and inconsistent irrigation. There are six short videos (each 11 minutes or less) in the series covering various aspects of irrigation. They are:
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Why Plants Need Water
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When to Water
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How Much to Water
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1-5 Moisture Scale
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Selecting the Right Tools
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Watering with a Hose
The videos provide the “why” behind irrigation decisions along with practical “how-to” lessons you can then take and customize to your own crops and facilities. The videos use simple everyday language rather than technical jargon. Many of the topics include hands-on activity plans and printable summaries.
The main benefits of these FREE irrigation videos are to increase employee confidence making independent irrigation decisions for more uniform plant growth and reducing over-watered crops.
All of the topics are available in English and Spanish, and in case I haven’t mentioned it yet, they’re absolutely FREE. There's no registration, gimmicks or time constraints—anyone can watch them whenever, wherever and as often as they want.
Simply go to
backpocketgrower.org/training and select “Professional Irrigator” from the list of options. You can then select which irrigation topic you’d like to watch. Easy, peasy.
More Free Training
While compiling the Professional Irrigation training video article above, I discovered the University of Florida IFAS Extension has an entire series of FREE training sessions covering a range of relevant, grower-related topics.
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Introductory Greenhouse Employee Training
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Irrigation
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Water Quality
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Substrate Physical Properties
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Fertilizers, Nutrients, pH and EC
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Cutting Propagation
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Grower Case Studies
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Climate (light, temperature and humidity)
Each topic typically includes multiple 10-minute-or-less videos. Similar to the irrigation videos, they're both informative and easy to understand. Every topic is available in English and Spanish. If you're looking for some basic introductory training you can provide your staff, look no further. I see these videos as discussion starters that can be used to expand on the knowledge base presented and continue the training as each topic applies to your production facilities and growing practices.
If you’re looking for more in-depth and technical training, the University of Florida has you covered, as well. They offer an online Greenhouse Training Certificate Program covering a wide range of specific topics under three core programs: Plant Health, Elite Grower and Root Zone. There's a charge for each high-quality, information packed course. All courses are available in English and Spanish.
I know many greenhouses who are happy with the training they received when having their employees take these online programs and earn the certificates. Perhaps I can add you to this list.
My email is paul@pace49.com if you have any comments, article suggestions or if you'd just like to say hello.
Best regards,
Paul Pilon
Editor-at-Large—Perennial Pulse
National Sales Manager—Pace 49, Inc.
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