Replacing Roses Affected by Rosette Disease

Time after time designers, landscapers, municipalities and homeowners overuse certain plants to the point of making them a monoculture and then an insect or disease comes along and wreaks havoc. We’ve seen it with elm trees, ash trees and now we are seeing it with landscape roses. Rose Rosette Disease (RRD) is now knocking out landscape roses particularly in the South. The virus is spread by a tiny eriophyid mite that has an association with multiflora rose, so the disease is likely to intensify throughout the Midwest in states where multiflora rose has naturalized.  At the moment there is no cure for Rose Rosette Disease, so infected roses need to be destroyed and replaced with something other than roses.

Roses infected with Rosette Disease look like they've been sprayed with herbicide

While almost all roses are susceptible to RRD, a few specific landscape rose varieties have been hit particularly hard because of their popularity with landscapers and their use in larger mass plantings. The popular question now is what shrub should be used to replace these roses? First off, we should not replace these infected roses with just one single species or cultivar lest we tempt fate once again. We should be looking at multiple species and cultivars, particularly those shrubs that offer similar characteristics that made these roses so useful and popular in the first place.   

Conceptually, the type of shrub landscapers and designers are looking is colorful, carefree, is long blooming or has season-long interest, looks good as a mass planting, thrives in full sun and is less than five feet tall. There are a number of shrubs that meet that criteria and here are some of the Proven Winners® shrubs that fit the bill.

Abelia – Full sun

Long blooming shrubs, many with colorful foliage and fragrant flowers.

               Bronze Anniversary™ - 3-4’

               Ruby Anniversary™  - 4-6’

               Sunny Anniversary® - 3-4’

               Pinky Bells® - 3-4’

               Fairy Dance™ - 2-4’

Ruby Anniversary™ Abelia chinensis

Aronia – Chokeberry – Full sun

Low Scape® Series - A tough native with white spring flowers, glossy foliage and exceptional fall color.

                              Low Scape® Hedger - 3-5’

                              Low Scape® Mound - 1-2’

Lo Scape® Mound Aronia in autumn

Azalea – Rebloooming – Full sun to partial shade

Bloom-A-Thon® Series - Compact evergreen shrubs with showy flowers that appear in the spring and fall.

Bloom-A-Thon® Hot Pink – 3.5-4.5’

Bloom-A-Thon® Lavender – 3.5-4.5’

Bloom-A-Thon® Pink Double – 3.5-435’

Bloom-A-Thon® Red – 3-4’

Bloom-A-Thon® White - 2.5-3’

Bloom-A-Thon® Double Pink Azalea

Berberis – Barberry – Full sun

               Sunjoy® Series - Tough, easy to growing shrubs with colorful foliage. 

          Sunjoy® Cinnamon - 4-5’

Sunjoy® Citrus - 2-3’

Sunjoy® Gold Pillar - 3-4’

Sunjoy® Syrah - 4-5’

Sunjoy® Tangelo - 3-4’

Sunjoy® Series of Barberry

Buddleia – Dwarf Butterfly Bush - Full Sun

Continuous flowering, low growing shrubs with colorful, fragrant blooms.

               

          Lo & Behold® Series – Dwarf, sterile shrubs that come in a wide range of colors.

Lo & Behold® Blue Chip - 2-2.5’

Lo & Behold® Blue Chip Jr. - 1.5-2.5’

Lo & Behold® Ice Chip - 1.5-2’

Lo & Behold® Lilac Chip - 1.5-2’

Lo & Behold® Pink Micro Chip - 1.5-2’

Lo & Behold® Purple Haze - 2-3’

Lo & Behold® Pink Micro Chip

Miss Series – Semi-dwarf shrubs with vibrant colored, fragrant flowers.

               'Miss Molly' - 4-5’

               'Miss Pearl' - 4-5’

               'Miss Ruby' - 4-5’

               'Miss Violet' - 4-5’

Miss Violet Butterfly Bush

Pugster™ Series - Dwarf shrubs with large flowers with a wide range of colors.

                    Pugster™ Blue - 2’

Pugster™ Periwinkle - 2’

Pugster™ Pink - 2’

Pugster™ White - 2’

Pugster Blue™ Butterfly Bush

Ceanothus hybrids – New Jersey Tea - Full sun

               Marie Series™ - Drought tolerant shrubs that thrive in poor soils.

                              Marie Bleu™ - 2-3’

                              Marie Gold® - 2-2.5’

                              Marie Rose™ - 2-4’                  

         

Marie Blue™ Ceanothus

Clethra alnifolia – Summersweet - Full sun to partial shade

Easy to grow native shrubs with later summer, fragrant flowers and yellow fall foliage

               Sugartina® Crystalina - 2.5-3’ 
               Vanilla Spice® - 3-5’

Sugertina® Crystalina Summersweet

Deutzia gracilis – Slender Deutzia - Full sun to partial shade

Yuki® Series – Tough, ground covering shrubs with abundant spring flowers and burgundy fall color.

                              Yuki® cherry Blossom - 1-2

                              Yuki® Snowflake - 1-2’

Yuki Cherry Blossom™ Deutzia

Diervilla – Bush Honeysuckle - Full sun to partial shade

          Kodiak® Series – Tough, native shrubs with colorful spring and autumn foliage.

Kodiak® Black - 3-4’

Kodiak® Orange - 3-4’

Kodiak® Red - 3-4’

Kodiak® Orange Diervilla

Hibiscus syriacus – Dwarf Rose of Sharon or Althea - Full sun

               Lil’ Kim™ Series – Dwarf series from Korea with colorful, long blooming flowers.

                    Lil’ Kim™ White - 3-4’

Lil’ Kim™ Red - 3-4’

Lil’ Kim™ Violet - 3-4’

               PollyPetite™ - 3-4’,  A sterile, dwarf hybrid with a large clear lavender blooms

Pollypetite™ Hibiscus

Hydrangea arborescens – Smooth Hydrangea - Full sun

               Lime Rickey® -  4-5’, Attractive green flowers

               Incrediball® -   4-5’, Large flowers emerge green, turn white and age to green.

               Incrediball® Blush -   4-5’, Large lavender-pink flowers on strong stems.

               Invincibelle® Series – Compact/dwarfs with strong stems, wide range of colors.

                    Invincibelle® Limetta™ - 2.5-3’

Invincibelle® MiniMauvette™ - 2.5-3’

Invincibelle® Ruby - 2-3’

Invincibelle® Spirit II - 3-4’

Invincibelle® Wee White™ - 1-2.5’

Invincibelle® Spirit II (Two) in our trial fields

Hydrangea macrophylla – Reblooming Bigleaf Hydrangea - Full sun to partial shade

               Let’s Dance® reblooming series – Reliable, long blooming, rich flower colors.

          Let’s Dance® Big Easy® - 2-3’

          Let’s Dance® Blue Jangles® - 3-4’

Let’s Dance® Diva! - 3-4’

Let’s Dance® Rave™ - 2-3’

Let’s Dance® Rhythmic Blue™ 2-3’

Let's Dance® Big Easy™ Hydrangea

Hydrangea paniculata – Dwarf Panicle Hydrangea - Full Sun

               Bobo® - 2.5-3’

               Little Lime® - 3-5’

               Little Quick Fire® - 3-5’

Bobo® Hydrangea

Hydrangea serrata – Serrated Hydrangea - Full sun to partial shade

             Tuff Stuff™ Series – Selected for hardiness and reliable blooming.

Tiny Tuff Stuff™ - 1.5-2’

Tuff Stuff™ - 2-3’

Tuff Stuff™ Red - 2-3’

Tiny Tuff Stuff™ Hydrangea

Hypericum –St. Johnswart - Full Sun

               Sunny Boulevard® - 2-3’, Tough, drought tolerant and long blooming

Sunny Boulevard® Hypericum

 Itea virginica – Dwarf Sweetspire - Full sun to partial shade

Little Henry® - 2-3’, A dwarf selection with early summer blooms and excellent orange-red fall color.

Little Henry® Itea

Lagerstroemia – Dwarf Crapemyrtle - Full sun

               Infinitini® Series – Dwarf compact shrubs, that flower even if they die back.

Infinitini® Brite Pink – 2-4’

Infinitini® Magenta – 2-4’

Infinitini® Orchid – 2-4’

Infinitini® Watermelon – 2-4’

Infinitini® Magenta

Ligustrum - Privet - Full sun to partial shade

               Golden Ticket® - 4-6’, A non-invasive, non-burning, bright yellow-green foliage.

Loropetalum – Dwarf Chinese Fringe Flower - Full sun to partial shade

Jazz Hands® Series – Selected for healthy growth and attractive flowers and foliage.

Jazz Hands® Bold – 5-6’

Jazz Hands® Dwarf Pink – 1-3’

Jazz Hands® Dwarf White – 1-3’

Jazz Hands® Mini – 1’

Jazz Hands® Variegated – 4-6’

Jazz Hands® Bold and Mini

Physocarpus – Dwarf Ninebark - Full sun

Dwarf selections with colorful foliage and a high level of mildew resistance             

Festivus Gold® - 3-4’

Tiny Wine® - 3-5’

Tiny Wine® Gold – 3-5’   

Potentilla – Bush Cinquefoil - Full sun

Happy Face® Series - Tough, free flowering native shrubs with a range of colors.  

Happy Face® Pink Paradise – 2-3’

          Happy Face® Yellow – 2-3’

HappyFace® White - 2-3’

Happy Face®  Yellow Potentilla

Spiraea - Spirea - Full sun

Double Play® Series – Attractive spring foliage color and superior flowering.

                    Double Play® Artisan® - 2-2.5’

Double Play® Big Bang™ - 2-3’

Double Play® Blue Kazoo® - 2-3’

Double Play® Candy Corn™  - 1.5-2’

Double Play® Gold – 1.5-2’

          Double Play® Painted Lady™ - 2-3’

          Double Play® Pink – 2-2.5’

                    Double Play® Red™ - 2-3’

Double Play® Blue Kazoo® Spiraea

Weigela - Weigela - Full sun

Sonic Bloom® Series – Continuous flowering in a range of flower colors.

Sonic Bloom® Pearl – 4-5’

Sonic Bloom® Pink – 4-5’

Sonic Bloom® Red – 4-5-

Wine Series™ – Early summer flowers and attractive burgundy foliage

Fine Wine® - 2-3’

Spilled Wine® - 2-3’

Wine & Roses® - 4-5’

Sonic Bloom® Red Weigela

The Trials and Tribulations of Plant Evaluation

Most all of these roses will be thrown out.

Please don't tell this to my rose breeders, but part of my responsibility as a plant hunter is to throw away roses; as many as possible, and as soon as possible.  You see, trialing plants is an expensive business.  It takes a lot of greenhouse space, a lot of land, and a lot of labor.  But if you want to introduce the best rose (or other shrub variety), you have no choice. You have to do it. Just take a look at all the beautiful roses in this picture. Some of you would say, "I'd love to have any of those plants in my garden!" but that's not quite true.  You would be happy if I gave you these roses to you for free, but you would not be happy paying your hard-earned-money for most of these roses. Trust me, that's why we throw them away. 

Roses may be pretty, but they're also a pretty tough business.  Currently, one rose dominates the marketplace. Growers, garden centers, and yes, even consumers are content with one rose, even if there are others just as good (and there are).  Having one dominant rose simplifies life, because you don't have to think and you don't have to choose. Don't argue with me on this, because I know it's true: people vote every spring with their dollars and for the last fifteen years the vote has been for one rose.

The only hope to successfully introduce a new rose is to work with multiple rose breeders, to test and trial a lot of potential new varieties, and after three or four years of trialing, throw the vast majority out. The idea is to sift through the chaff to find the very best plants. We start the process by growing the roses in containers in a greenhouse. We never spray them with fungicides. We over-head water them each day, and keep them in the same container for 2-3 years until they're so stressed that they succumb to disease. Most roses do. In addition, we plant them our in a trial garden following the same protocols and let Darwinism takes over. Survival of the fittest. After twenty years and hundreds upon hundreds of rose selections on the trash heap, we have introduced only sixteen rose varieties under the Proven Winners brand. They have won six prestigious awards.

This is pretty much the same process that we go through for all the Spiraea, Hydrangea, Syringa (lilacs) and every other species of shrub that we trial.  

Someone has to document and analyse the trial data so we can get to the best plant. We have a team of six people that help to evaluate plants and decide what gets introduced.

We evaluate them in greenhouses to make sure they'll perform well for the nurseries that buy and grow our plants. We have to find out how fast  it finishes in a one and three gallon pots, and determine how it looks in the spring when our customers do their shipping to garden centers. How does it present in the container? Does it get mildew? Does it grow too fast or does it grow too slow? How often does it need to be pruned and will it hold up its flowers? 

This Spiraea evaluation is about more than just judging the flowers.

The Double Play® series is noted for beautiful flowers and foliage. Double Play Big Bang has become an industry favorite because of its unique orange foliage and large flower size. 

Will it be in bud or bloom in the spring when people shop for plants? If not, does it have interesting foliage that make it showy enough to grab your attention amongst all the other spirea? I bet you didn't know we were so critical of our plants!

Many of these Spiraea seedlings are beautiful, but nearly all will be discarded.
Our late nursery dog Zoe (RIP) loved evaluating seedling plants. The job now belongs to Rosie.

Breeders have traditionally bred for better flowers; Why not? People love flowers. 

Breeding starts with a question or an idea. What would make for a better spirea? Traditionally plant breeders have been obsessed with flowers and understandably so. New colors and bigger is better have been the drumbeat most often followed. People love flowers and so yes, of course we need to breed for flowers, but there has to be more. A beautiful woman (or man) with nasty disposition is not all that attractive and the same is true for plants. We want our plants to be pleasant, agreeable, and low maintenance. That means we have to test and trial a plant, a process that can take ten years or more. 

Each row represents a unique selection that is evaluated for form, sunburn resistance, growth rate, foliage color and length of bloom. The new plants are compared against best plants on the market

Believe it or not, just thirty years ago, shrubs were not grown in containers. They were grown in a field, dug while dormant in early spring, and sold as bare-root (without soil) or balled and burlapped.  It never mattered if a plant looked good in a container. It never mattered if a shrub was dwarf or compact; in fact, the faster it grew, the better.  All this has changed and so has plant breeding, plant hunting, and plant introduction.  We have to consider all these things and more. Someone has to document and keep track of all this information.  We might have to evaluate thirty five potential spireas just to find one plant worthy of introduction. And it will have to have beautiful flowers and beautiful foliage, as well as superior hardiness and heat tolerance.  People are no longer content with plants like forsythia and mock orange that flower for two weeks and grow fifteen feet tall. Every inch in a consumer's yard and garden is valuable space and they want their plants to look good in the spring, summer and fall. That means we have evaluate our shrubs in the spring, summer and fall for season-long interest.   

Evaluations take place from spring through fall to document all the seasons of color.

Some things are easy to test for, like powdery mildew on dark-leaved Physocarpus (ninebark). We have been breeding and trialing dark ninebark for over fifteen years and have only introduced five plants out of thousands. Just as black spot has been the question mark on roses, "To mildew or not to mildew, that is the question" with ninebark. I'm often happy to find diseases on plants, so long as it's early in the evaluation process. It is an easy reason to narrow the field and hone in on the best plants.

Greenhouse container trials help us weed out the weaker plants. Ninebark, Spiraea, Syringa, hydrangea
and Rosa are all susceptible to mildew. It's easy to spot on dark leaves. Note the clean selection to the right.  

At Spring Meadow, we begin the process by throwing away plants in our seedling test field. We walk our fields regularly with a can of orange paint, and if a seedling is diseased, weak, floppy, or no better than the best plant we sell, we mark it with neon orange paint. Within days, they're dug up and gone, and after two or three years, you are down to just a few very good plants. If we're lucky, one plant will stand alone and we'll have a potential new introduction. 

The original Fire Light® Hydrangea in our breeding field. Note all the open
 space where lesser plants were removed. Clearly, the best plant remained.

Spring Meadow President Dale Deppe stands next to the original Scent and Sensibility lilac
in our breeding field. Again, note the open space in the field.

You would think this was the happy ending, but it's not. We will then propagate thirty to a hundred plants from the original mother plant for further evaluation. In addition to container trials, we plant some back to the test field and some to our trial garden. The work has only just begun. Once you root cuttings of a plant, there is no guarantee that the new plants will grow and behave like the original seedling; sometimes they grow slower and other times faster. Some plants are too difficult to root and never make it past this stage. More importantly, we have to determine if the plant is actually better than its potential competition. Sometimes that's obvious. The three hydrangeas below are good examples.

Fire Light® hydrangea stood out against all the other plants on the market

Bobo® hydrangea was a clear winner in our field and container trials.

Other times it takes a few years to sort things out, like with the caryopteris below. There used to be two selections in this row, but the one the foreground was killed after two hard winters. In this case, winter made the final decision for us and we now have a very hardy selection.   

Sunshine Blue® II was a dramatic improvement in hardiness over the original. 

Trialing and testing new plants is very crucial if you are selling plants under a brand as we do. Branding is more than just a pot and tag; it is more than advertising and marketing. Branding is the relationship we have with customers. And like most relationships, it all comes down to trust. Our brand relationship is on the line every time someone buys one of our plants. People are either going to have a good experience or a bad experience, either of which they will associate with the brand, so we do everything possible to make sure it's a good experience. It not always easy because we're selling live, perishable products. 

Good brands know that the product testing and improvement does not stop after the product launch.  We have to continue to improve upon what we've introduced, even if it's never even noticed.  A few years ago we introduced a new dwarf Buddleia (butterfly bush) called Lo & Behold® 'Blue Chip Jr.' The goal is to replace 'Blue Chip' with a better plant, because our growers wanted a smaller, less brittle plant that bloomed earlier and longer. Over the years we have added to this line, improving the colors, the habits, and the bloom time. The Caryopteris I wrote about earlier is another example of continual improvement. Sunshine Blue® was a very good plant that sold well, but we replaced it with something better. 

We have moved up the bloom time with each introduction in this series of dwarf butterfly bush.
The original 'Blue Chip' (on the far left) is far from blooming in this trial.

Creating a full and vibrant color range for the Lo & Behold® series was important.
These seedless, non-invasive have won numerous awards for innovation.  

Hydrangea 2.0: Invincibelle® Spirit II being discussed in our test field

Perhaps one of the more dramatic product improvements in our brand has been been with Invincibelle® Spirit hydrangea. Last year we issued an update on this plant that has strong stems, a more compact habit, and richer flower color. There is no such thing as a perfect plant and we have introduced some plants that came short of the mark, and so we have get back to work and make it better. The first iPhone was not perfect and certainly Apple will improve upon the iPhone 6. It's a pain to change, but everyone respects their leadership, innovation, and their relentless quest for improvement.  Their products continue to delight people worldwide. There are people that complain we introduce too many plants, and I sympathize, but we must keep improving if we are to remain relevant. We must continue to come up with a better roses, better hydrangeas, and every other shrub type. If we fail to delight our customers, they will vote with their hard-earned money and spend it on other things that will delight them. 

A new, continuous blooming, carefree, fragrant rose. At Last is available on a limited basis from Better Homes and Gardens). The 2016 National Champion of Shrub Madness.  

Rigorously trialing plants is hard work and time consuming, but it is also rewarding. A good example is the At Last™ rose seen above. It was one of the few roses that proved itself in our trials. It rose to the top because of its superb disease resistance and ability to continuously bloom all season long. To make things even better, it has a rich spicy fragrance until now never found in a high-end, disease resistant rose.  To gain even greater confidence in the rose, we have given out over 40,000 plants to our top growers this spring. The roses were given out with only one condition: that that they cannot sell them. They are to be given away to garden writers, bloggers, garden center retailers, landscape designers, and botanical gardens to be trialed and tested across North America. It is the first plant to be tested so rigorously, and we want to have the highest level of confidence before we release it to the general public. If you were included on the list above, contact Spring Meadow Nursery to request a plant. If you were not included on the list but still want to trial this rose, there are a limited number of plants available for purchase from Better Homes and Gardens.