More Shrubs That Can Be Greenhouse Forced

More Shrubs That Can Be Greenhouse Forced

In the last installment, I sorted many common shrubs into “ease of forcing” groups, based on characteristics such as their visual impact in a container and disease problems.

Group 1: Would not fit into a mixed container program for the spring, including those with no outstanding features to their foliage or susceptible to disease. Since flowers were only formed on next year’s growth, forcing for flowers was out of the question.

Group 2: Will work for a spring program, but with numerous problems such as poor form, inconsistency of growth or flowering or unstable variegation.

Group 3: These plants work in the greenhouse, but require a bit more time, more marketing, etc.

Group 4: Plants that are easily forced and catch the eye. This group proved to be the most uniform, most colorful and most appealing to the eye of the consumer.

We determined the need, if any, for cold for all the shrubs brought into the program and sensitivity, if any, to photoperiod for many of them. Rooted liners in 32 tray packs were subjected to 33ËšF to 37ËšF in coolers for zero, four, six, eight or 10 weeks. Photoperiod treatments (long days or short days) were provided after the plants were removed from the cooler, planted in gallon containers and placed on the bench. The research was conducted on many taxa over a period of three years. No growth regulators were applied.

Here are a few others that fit in Group 4. Due to funding limitations, we did not look at them as closely as other subjects.

1. Buddleia ‘Peacock’: One of the better butterfly bushes we trialed.

z 34ËšF-37ËšF
y values followed by the same letter are not significantly different at p=0.05

Comments: Cold not necessary, this is one of the few shrubs that flower sufficiently on the bench. A short duration of cold reduced the bench time.

Recommendation: Receive plants in November, cool for six weeks. Plant in final containers and place on bench.

Results: A marketable plant will finish in 11 weeks in a gallon container.

2. Abelia ‘Silver Anniversary’: An excellent variegated shrub for the South. The variegation is appealing and stable.
z 34ËšF-37ËšF
y values followed by the same letter are not significantly different at p=0.05

Comments: Do not cool more than 6 weeks, and if long crop time is acceptable, do not cool at all. Cooling results in rapid death.

Recommendation: Receive cuttings in early November, transplant to final containers and place on bench.
Result: A marketable plant approximately four to five months after planting in a 1-gallon container.

3. Kolkwitzia ‘Dream Catcher’: One of our favorite shrubs, producing pendulous stems of coppery gold leaves. Very cold hardy.
z 34ËšF-37ËšF
y values followed by the same letter are not significantly different at p=0.05

Comments: Plants require cold or LD (data not shown). If provided with LD, little cold is needed. However if LD are not possible, cold is required

Recommendations: Receive cuttings in November, place in cooler for six weeks and then provide LD (night break lighting) in the greenhouse, or leave in cooler for eight weeks if plants are to be grown under natural winter days.

Results: A marketable plant in 12 weeks in a gallon container.

In summary, there are dozens of shrubs that can be grown in the greenhouse. There are many problems; probably the most limiting is the lack of a consistent supply of uniform cuttings. This is where the research efforts should be concentrated in the future.

 These articles demonstrably show that forcing shrubs can be accomplished in a reasonable amount of time. The selection is important, as we have also shown that not all plants lend themselves to these practices. I have no doubt the retail market is ready for more shrubs than ever before. With a proper marketing program, good signage and a consistent product, I see shrubs as the next perennials. After all, they are simply “perennials with bark.”

Leave a Reply

More From Varieties...
National Garden Bureau California Vegetable Summer Trials

May 26, 2016

California Summer Vegetable Trials In August Will Cover A Wide Range Of Crops

The National Garden Bureau is once again organizing summer vegetables trials this August in California, giving attendees the opportunity to visit with several breeding companies.

Read More
Eason 2017 Perennials Guide

May 25, 2016

Eason Horticultural Resources Releases New Perennials Guide And Spring Trials Report

The two guides are available in digital and print versions and offer information from several breeders.

Read More
Echinacea ‘Butterfly Rainbow Marcella’

May 25, 2016

15 New Perennials For Bees, Butterflies, And Other Pollinators

These 15 new perennials, available for retail in 2016 and 2017, will produce colorful flowers and foliage year after year, providing habitat and food for bees, butterflies, birds, moths, and other pollinators.

Read More
Latest Stories
National Garden Bureau California Vegetable Summer Trials

May 26, 2016

California Summer Vegetable Trials In August Will Cover…

The National Garden Bureau is once again organizing summer vegetables trials this August in California, giving attendees the opportunity to visit with several breeding companies.

Read More
Eason 2017 Perennials Guide

May 25, 2016

Eason Horticultural Resources Releases New Perennials G…

The two guides are available in digital and print versions and offer information from several breeders.

Read More
Echinacea ‘Butterfly Rainbow Marcella’

May 25, 2016

15 New Perennials For Bees, Butterflies, And Other Poll…

These 15 new perennials, available for retail in 2016 and 2017, will produce colorful flowers and foliage year after year, providing habitat and food for bees, butterflies, birds, moths, and other pollinators.

Read More
P.Allen Smith Cut Flowers

May 25, 2016

Sakata Seed America And P. Allen Smith Extend Partnersh…

Sakata is taking its partnership with plantsman P. Allen Smith a step further to create the P. Allen Smith Home Grown Cut Flowers Collection, a selection of premium cut flower seed hand-picked by Smith and bred exclusively by Sakata.

Read More
Coleus Fancy Feathers Pink (Terra Nova Nurseries)

May 23, 2016

Take A Sneak Peek at Terra Nova Nurseries’ New Coleus F…

A brand-new collection of Terra Nova Nurseries coleus varieties called the Fancy Feathers Series is now available to growers for online orders. The series produces narrow, feather-like leaves and offers a mounded habit.

Read More
Rotary Botanical Gardens, Wisconsin

May 16, 2016

All-America Selections Summer Summit In Madison, WI, Wi…

Registration is now open for the 2016 Summer Summit, which takes place in August and features a focus on the locally grown movement.

Read More

May 10, 2016

13 New Native Plants And Nativars For Going Green [Slid…

Native plants are becoming a bigger part of living green, as consumers become more aware of the role regional native plants play in promoting biodiversity in the garden, in urban landscapes, and in habitat restoration. Here are 13 new native plants breeders are offering to consider for your product mix.

Read More
Pennisetum alopecuroides ‘Ginger Love’ (Aris Greenleaf Plants)

May 10, 2016

12 New Ornamental Grasses For Low Maintenance Garden Ap…

Nothing says low maintenance like ornamental grasses. They add texture, movement, and all-season color to the garden. Check out 12 new ornamental grasses and grass-like varieties for growing in your greenhouse or the garden.

Read More
Blueberry ‘BrazelBerries Perpetua’ (Fall Creek Farm & Nursery)

May 9, 2016

Why Star Roses And Plants Is Buying The BrazelBerries P…

The purchase includes the brand, variety portfolio, and grower network, and allows Star Roses to capitalize on increased berry consumption among consumers.

Read More
Wave Petunias Team

May 3, 2016

Hot Pink Wave-Rave Van Making Its Way To The Big Apple …

Imagine driving down the road, minding your own business, when you’re passed by two smiling, waving, happy women driving a hot-pink van that’s adorned with petunia and pansy flowers. That’s not something you see every day, but motorists in the Midwest and Northeast may catch a glimpse of the Wave-Rave van this week as Ball Horticultural Co.’s Claire Watson, Product Marketing Manager, and Katie Rotella, Marketing Communications Manager, make their way to a media tour and plant giveaway in New York City. Watson and Rotella visited Cleveland’s WOIO Channel 19 news on Tuesday morning to tell consumers about Wave Petunias and Wave Pansies, and remind them to visit their local garden centers to purchase gifts for Mother’s Day this weekend. Check out this clip on Periscope. After the morning news, the ladies stopped by to visit the Greenhouse Grower staff at Meister Media Worldwide in Willoughby, OH. Next stop: Chelsea Garden Center in Brooklyn, NY, where […]

Read More
National Garden Bureau CAST 2016 Bloggers

May 3, 2016

5 Things Gardens Bloggers And Writers Learned At Califo…

For the second year in a row, the National Garden Bureau hosted five popular garden bloggers and writers on a trip to California Spring Trials. Here’s what each of them had to say about their experience.

Read More
Chick Charms

April 29, 2016

Kelly Norris: Why The Plant Collector Market Is Set To …

In his latest column for Greenhouse Grower magazine, Kelly Norris says there are more plant collectors out there than we think, which opens the way for the gift plant market to explode.

Read More
Pennisetum Fireworks

April 28, 2016

Why Ornamental Grasses Are Great For People In Condos A…

Allan Armitage says breeders need to do a better job of making growers, brokers, and garden centers aware of better ornamental grass cultivars for the increasingly shrinking garden space.

Read More
Andropogon gerardii Blackhawks (Intrinsic Perennial Gardens)

April 27, 2016

Know Your Market When Choosing Ornamental Grasses

Growers have no shortage of choices in the ornamental grass market. Narrowing down the selection comes down to finding the right plant for the right purpose.

Read More
Bee on Bidens

April 25, 2016

Breeders Go The Distance To Bring New Plant Varieties T…

Breeders are meeting the demand for new varieties that perform and sell well by extending trialing to engage the grower community, using advanced technology, and encouraging international collaboration.

Read More
Dr Allan Armitage

April 20, 2016

Growers And Breeders Are Always Looking For A Better To…

While edibles become more diverse, there's one goal that hard-core gardeners and urban foodscapers share.

Read More
Syngenta Pentas

April 20, 2016

Syngenta Flowers Opens Its Perennial Genetics To The Ma…

California Spring Trials 2016 visitors to Syngenta Flowers found the breeder company and its employees happy and excited for the future, in the wake of the announcement of its acquisition by ChemChina. Now Syngenta Flowers is ready to move forward with its breeding efforts in geraniums, pentas, and other crops, and it is opening its perennials offerings to the whole supply chain for a better chance to get those plants to retail.     Syngenta Wants To Revolutionize Geranium Breeding The big news in this year’s trial, says Karl Trellinger, Technical Services Representative at Syngenta, is the change in Syngenta’s breeding efforts in geraniums and pentas. The Calliope geranium series, long considered a premium line in the market, is getting a makeover. Growers have told the breeder that they love the colors available in the Calliope series, but the plants are just too vigorous for smaller containers and combinations. As […]

Read More
Petunia Vista Bubblegum (Proven Winners)

April 20, 2016

Proven Winners Funds Gardening “It Couple,” Names Plant…

Since 1992, Proven Winners has been changing the gardening game, and it’s not stopping now. With new plants, improved series, and interesting retail customers, the brand aims to make planning easier for growers, and make gardening easier and more fun for consumers. At its new 2016 California Spring Trials location at Kirigin Cellars in Gilroy, Proven Winners had the space and a beautiful setting to lay all of its offerings out, from new and improved varieties in annuals, perennials, and shrubs, to marketing and retail programs. Check out the slideshow below for highlights.   Proven Winners Is Flexing Its Marketing Muscle One of the ways Proven Winners is working toward better use of its products and gardening in general, is by supporting the gardening authorities that gardeners of all ages trust on social media. Director of Marketing Marshall Dirks says while searching for influential gardeners, he came across a young […]

Read More
[gravityform id="35" title="false" description="false"]