Perennial Combos, HydraFiber, Bacterial Diseases and PPA Announcements

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News and commentary for the perennial market GrowerTalks MagazineGreen Profit Magazine

Wednesday, May 10, 2017

Paul Pilon Subscribe
Perennial Pulse

What's Going on Here?Perennial Combos Echinacea Green Twister
Scholarship Recipients
PPA Symposium
The Answer Is...
Bacterial Leaf Spots

What’s Going on Here?

With the April newsletters being devoted almost entirely to Spring Trials, we weren’t able to play the diagnostic game where I show you a cultural problem and you use your mad skills and attempt to identify the issue in the image. Let’s get back on track. Here’s this month’s challenge:


Here’s an issue I occasionally observe on aquilegia. It frequently occurs under cool, wet growing conditions. That’s the only clue I’m going to give. It’s time for me to ask, “What’s going on here?”

Read on to see if you’re right and how to manage this problem. 

Why Aren’t Perennial Combos More Popular?

This combo from Dümmen Orange  contains Salvia Salute Ice Blue, Leucanthemum Sweet Daisy Cher and Gaillardia Spintop Red Starburst. 

In the last newsletter, I asked you for your thoughts as to why perennial combos haven’t become more popular. Here are a few of the comments I received:

Blair Hoey, Managing Director – Green Leaf Plants

“Past perennial combos at retail have worked as long as we incorporated some annual color into the product mix for the containers. Past experience showed us that straight perennial combos tended to go green towards the mid to late summer, which did not meet consumers’ needs for spring to fall color as an annual combination would deliver.”

Blair also offered:

“Great success has been had also with combinations using multiple colors of heuchera and hostas, again due to the season-long color produced by the varied leaf colors.” 

Jason Rekker, Senior Manager-Growing – Valleybrook Gardens Ltd. (Ontario)

“We’ve dabbled with them in the past, but cost was always an issue. Getting them to fill out properly requires multiple inputs and the plant cost adds up. Perennial plants are competing against usually much cheaper and much showier annual planters and baskets.
Second, the profit dollars per square foot of greenhouse space is just not there – planters would be displacing more profitable crops.
Third, freight costs are high -- again the large footprint of the planter displacing more profitable product from the racks.”

David Keeler

“The biggest drawback I see is that most combos are in above-ground containers, which kind of takes away the 'perennial' aspect of the combo here in Maritimes Canada and northern New England. And if they did survive (maybe replanted into the ground), odds are they would crowd each other out in pretty short order. If the customer could be trained to take the combo apart after Labor Day and plant the components in the ground with plenty of space, we might have some success. Otherwise, there's a strong possibility of consumer complaints the following year when their beautiful combos fail to re-grow.”

Martin Fisher – Plantstart e.K. (Germany)

“Main problem is the price calculation of such a combo, so you don’t do it if nobody forces you to. Who is giving you back what you deserve to get for it? The breeders are not of help because they promote TC plants with high royalty rates. The third aspect is the relatively short shelf life of a flowering perennial itself. I cannot cut back and keep the whole pot in shape. So single pots are less risky and much more profitable.”

Anne Leventry – PanAmerican Seed

“We have been promoting these at Kieft for the last couple of years and there seems to be a lot of interest when people see them, but they don’t gain much traction in the marketplace. My own theory is that they are more difficult (in general) than annual combos. And sometimes you need to work with young plants of different sizes to get everything to size up and flower together.”

It looks like there are several factors leading to the lack of increased popularity of perennial combinations. Return on investment seems to be the most prominent reason, but other factors, such as ease of production and long-term consumer success, seem to be the other major concerns.

I barely received any feedback from those who've been successful with perennial combos. Does that mean no one is growing and marketing them successfully? I hope that's not the case. If you have a success story you're willing to share, please contact me at 

Echinacea Green Twister

Here’s a great new echinacea introduction from Jelitto Perennial Seeds. Green Twister is a unique and colorful novelty seed selection. The edges of the flower petals are generally green (nearly yellow) and naturally vary slightly from plant to plant. The flower petals transition to a purple coloration as they approach the carmine red cones. Many of the stems appear burgundy colored. It blooms shorter during its first growing season, but reaches approximately 36-in. (91-cm) tall its second year and thereafter. Green Twister is hardy all the way to USDA Hardiness Zone 3. This distinguishable seed cultivar is an affordable alternative to many of the more expensive tissue culture cultivars. 

New Growing Mix Component


Have you heard about the new component for growing mixes that's spreading across our industry like wildfire (I mean that in a positive manner)? I’m referring to a new wood fiber product called HydraFiber. HydraFiber is engineered using a proprietary thermally refined process using pressure and steam to rub the wood fibers from the loblolly pine. This patented process results in a very consistent, cost-effective media component. 

HydraFiber is currently being used to replace components such as perlite and coconut coir. However, due to its water-holding capacity, rewetting characteristics and air porosity, HydraFiber can possibly also be used to replace some of the peat moss and even pine bark in many growing mixes. With its compressed bales, there’s a reduction in shipping costs and storage space. It’s also readily available, so there's no need to order and receive a whole season’s supply all at once.


HydraFiber is available in four grades (fiber sizes) to growers who blend their own growing mixes. Working with HydraFiber does require specialized equipment from AgriNomix to refluff the fiber to its maximum volume. No need to worry if you don’t make your own growing mixes; HydraFiber is also available from a few companies (Oldcastle, Berger and GroBark) who offer this component in some of their blends.

It’s too early to determine whether or not HydraFiber is the best new advancement our industry has seen in commercial growing mix components. Perennials are just beginning to get looked at, but from what I’m seeing, the results with HydraFiber are also comparable to the performance observed in other growing mixes. Consider trialing mixes containing 20% to 30% 160- or 365-grade HydraFiber to provide better longevity and good drainage.

This is a very sustainable product that will likely result in some economic benefits compared to current growing mix components. Profile Products will be happy to evaluate your growing mix needs and determine the best strategy for your operation. Feel free to contact Jennifer Neujahr by email at or by phone at (630) 386-5926 to determine if there's an opportunity for HydraFiber at your greenhouse or nursery. 

PPA Scholarship Recipients

The Perennial Plant Association (PPA) has awarded eight outstanding students a full scholarship to attend the upcoming 35th Perennial Plant Symposium in Denver, Colorado, July 23-28, 2017.

"The students were selected from a deep pool of impressive applicants,” said Steven Still, PPA Executive Director. “They share a passion for perennials and goals of working in the perennial industry as growers, landscape designers, retailers and educators.”


Megan Haresnape is one of the scholarship recipients. She's a sophomore at Kansas State University studying Horticulture with a minor in Agribusiness. Her goal is to own and operate a greenhouse specializing in ornamental, herbaceous perennials and vegetable plants. She shares, “There will always be a demand for perennial plants and I want to be able to supply plants to help meet the ever-growing demand.”

2017 Scholarship Recipients

Lisa Gramse, Utah State University
Megan Haresnape, Kansas State University
Tyler Holtzman, Northern Virginia Community College
Rebecca Hutchison, Olds College, Alberta
Laurie Niven, Niagara Parks Commission School of Horticulture, Ontario
Megan L. Severance Shaner, Columbus State Community University
Sandra Vernon, Utah State University
Brett Zylstra, Niagara Parks Commission School of Horticulture, Ontario

The scholars receive an all-access pass to the entire six-day perennial symposium, industry tours, trade show, networking evenings, complimentary lodging AND a $1,000.00 stipend.

I’d like to congratulate all eight of the scholarship winners. I look forward to meeting you at the symposium.

35th Annual Perennial Plant Symposium

Speaking of the upcoming symposium, there’s still time to register for this great event.  The 35th Annual Perennial Plant Symposium and Trade Show is being hosted in Denver, Colorado, on July 23-28, 2017. 

There is an incredible lineup of speakers, including:

Brie Arthur – Professional Garden Communicator
Tony Avent – Plant Delights Nursery
Michael Bone – Denver Botanic Gardens
Dr. Raymond Cloyd – Kansas State University
Stephanie Cohen – Perennial Diva
Shannon Currey – Hoffman Nursery
Brent Heath – Brent and Becky’s Bulbs
David Salman – Waterwise Gardening, LLC

There’ll be 15 additional speakers, including myself.

Consider taking one of the tours to visit locations such as Britton Nursery, Center Greenhouse, Denver Botanic Gardens, Fort Collins Nursery, Garden of the Gods, Gulley Greenhouse & Garden Center, Colorado State University Trials, Paulino Gardens, Tagawa Nursery & Garden Center, and many more.

Learn more about this year’s Perennial Plant Symposium and register online at Early bird registration pricing is available through June 1. I hope to see you there. 

The Answer is …

At the beginning of the newsletter, I showed you a similar image to this one and asked if you knew what’s causing these leaf spots. If you guessed Pseudomonas leaf spots, you’re correct.

Leaf spots caused by Pseudomonas on aquilegia typically appear as dark brown to black water-soaked leaf spots. They most frequently occur along the margins of the leaves, but are commonly observed elsewhere across the leaf surface. These spots appear soft when the leaves are wet and sunken and brittle while the leaves are dry. Infected leaves will often turn chlorotic, beginning in the areas around or between the leaf spots.

Managing Bacterial Leaf Spots

The environmental conditions favoring the development of Pseudomonas and other bacterial leaf spots are free moisture (wet leaves), high humidity and temperatures ranging from 60 to 85F (15 to 29C). There must be free moisture on the leaf surfaces for bacterial leaf spots to develop. Frequent rainfall or applying overhead irrigation (particularly late in the day) can lead to the development and spread of bacterial infections. 

Good production and cultural practices is the first line of defense when it comes to bacterial leaf spot prevention. When possible, use disease-free starting materials, provide proper plant spacing, implement sound sanitation practices, do not handle plants when they're wet and avoid overhead irrigation during times when the foliage won't dry quickly after application.

Controlling bacterial diseases is extremely difficult; it's best to manage them on a preventative basis. There are no curative control options. Bactericides containing various copper compounds, phosphorous acid fungicides and streptomycin will help protect against bacterial disorders preventatively, but offer limited effectiveness once outbreaks have developed. Several growers have found KleenGrow to be another effective tool for managing bacterial diseases. I find tank mixing mancozeb with the copper bactericides increases the efficacy of the application.

Regardless, there are no good curative options for controlling Pseudomonas and other bacterial diseases. Use bactericides preventatively or when the environmental conditions are conducive for disease development. Alternating between the products I’ve mentioned would be better than relying solely on copper-based fungicides. 

I hope you enjoyed reading this edition of Perennial Pulse. I'd like to hear how your spring is going and what challenges you're facing. Feel free to email me sometime with your spring update and other article ideas (

Thanks for reading.

Take care,

Paul Pilon
Perennial Pulse

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