Experience the Psychedelic ‘Fifth Dimension’

Hibiscus rosa-sinensis ‘Fifth Dimension’ came to Longwood’s research greenhouses back in the late 1990’s when we were working on improving the vigor of the hibiscus display in our Rose House.  I soon fell in love with this psychedelic plant!

At first, it amazed me with its showy yellow flowers with silver centers.  Seeing silver on a flower stopped me in my tracks immediately!  It was mind altering.  Closer observation of this plant expanded my awareness to an even more amazing dimension. One day I noticed that the newly opening flowers were not yellow with a silver throat, but orange with a bronze throat.  Around noon, the trippy flowers morph from orange/bronze to yellow/silver. How groovy is that? It’s like having two kinds of flowers on the same plant.

When I told my photographer friend, Matt, about this amazing transformation over time, he decided to do a time lapse photography shoot, to capture the color change.  He did an amazing job.  I hope you enjoy this video as much as I do.

You can experience the ‘Fifth Dimension‘ in person at Longwood. The plant is on display in the Rose House and blooms throughout the year.

On a side note, we were able to improve the vigor of the hibiscus in the Rose House by grafting all of our hibiscus cultivars onto the vigorous rootstock, Hibiscus rosa-sinensis ‘Pride Of Hankins’.  I will let you in on a little secret: if you look closely at the hibiscus plants in the Rose House, you can see the graft union near the base of the plants.  Sometimes it is a clear line across the trunk, and sometimes it is more subtle—with only bark texture designating that there are two different plants joined together.

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‘Longwood Debutante’ Ready for Debut

Clivia miniata 'Longwood Debutante'

After 35 years of clivia breeding, Longwood Gardens is releasing its first named clivia when the North American Clivia Society holds its International Symposium and Show at Longwood Gardens March 19 and 20, 2011.  Clivia enthusiasts from around the world will be in attendance when ‘Longwood Debutante’ makes her debut into Clivia Society in the elegant Longwood Ballroom.  Scarlet O’Hara would be jealous!

Inside the research greenhouses

Back in 1976 when the breeding program started, clivias were commonly orange. The yellow flowers existing at the time were not impressive and rare, so Longwood decided to initiate a breeding program to produce a superior yellow clivia.  ‘Longwood Debutante’ has achieved the goal of the breeding program with its luminous yellow flowers that rise above the dark green foliage.  Her flowers are slightly fragrant with petals that overlap to produce a beautiful floral display.  This is the first release in a series of Longwood clivia cultivars.

Clivia berries containing seeds

Cliva seeds removed from the berry

Why did it take so long to release the first plant?  Thirty five years is a long time to wait. A good number of current students and employees  at Longwood were not even alive when the program started! One factor that slowed the program was the extended time it takes for a clivia seedling to mature.  Seedlings can take up to eight years to bloom from the time the seed is planted, so patience is needed.  Longwood speeds up the process in our research greenhouses by keeping the seedlings actively growing all year long, rather than allowing them to go dormant in the winter. The trick is to get the seedling to mature quickly—and maturity occurs when the plant produces 13 leaves.  Once the plant has 13 leaves, it is ready to produce a flower.  Then, when you finally have a blooming plant, the plants are slow to multiply.  It can take years for the parent plant to produce offsets. Results are slow in clivia breeding!

While breeding for the superior yellow flower, interesting mutations began to occur.  Both yellow and orange flowers began to exhibit a raised area, or keel, in some petals.  The term “keeling” refers the shape of the keel of the boat. The keeling petals add extra depth and interest to the flowers. We decided that the breeding program would also focus on accentuating the keel, in hopes of producing a multi-petal flower.  The normal number of petals on a clivia flower is six, but if the keel separates from the petals, a flower with nine petals can result.  Keeling flowers are interesting by themselves even if they don’t have extra petals. We now have some potential keeling cultivars in the works in our research greenhouses.

Longwood decided that a perfect venue for the release of ‘Longwood Debutante’ would be at the North American Clivia Society Show and Symposium. We have lined up an international cast of speakers including: Ken Smith from Australia, who manages the clivia registry; James Abel from South Africa, who is an expert on clivia in the wild; Harold Koopowitz, who literally wrote the book on clivia; Jim Comstock, who dazzles with a 3D clivia slide show; and Dr. Robert Armstrong, who started the clivia breeding program at Longwood.

Longwood’s visitors can enjoy the clivia show March 19 & 20 in the Exhibition Hall, as well as a special display of ‘Longwood Debutante’ in front of the Music Room. Everyone can register for the conference—you don’t have to be a member of a Clivia Society.  Conference attendees are invited to a dinner and auction of rare clivia plants on March 19. You can enter your plant into the show, too! This is your chance to show off your clivia plant.  A limited number of ‘Longwood Debutante’ will be available for sale in the Gardens Shop starting on March 20. We will also have orange and yellow bi-colored clivias for sale. You can own your own piece of Longwood history!

Clivia miniata 'Longwood Debutante'

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Grow in Green: Biodegradable Pots

Biocontainers offer an exciting opportunity for plant producers and home gardeners to become more earth friendly. Currently the majority of ornamental crops are produced in petroleum-based plastic containers. The extensive use of plastic results in a significant waste disposal problem and the plastic ends up in a landfill or hopefully gets recycled.

Biocontainers are containers that are not petroleum based and will degrade rapidly when placed in a composting operation or when field planted. Biocontainers fall into two categories: compostable biocontainers, which are designed to be removed from the rootball before the final planting and composted; and plantable biocontainers that are designed to be left intact on the rootball and planted directly into the field, landscape bed or final container. These biocontainers are designed to allow roots to grow through the container walls and to decompose after being planted. Some of the concerns when using biocontainers are the physical strength of the container and biodegradability.

Despite the introduction of many types of biocontainers, limited research has been conducted to evaluate these containers. Therefore, studies to test container wall strength and biodegradability was undertaken at Longwood Gardens, Louisiana State University and University of Arkansas.

Name and composition of biocontainers tested
Container Name	Container Composition
Plantable
Peat	Peat and paper
DOT® / Fertil®	80% Cedar wood fiber, 20% peat and lime
Cowpots®	Composted dairy manure and a binder
Cocofiber	Coconut husk fibers and a binder
Strawpots®	80% Rice straw, 20% coconut fiber and a binder
Compostable
OP47	Bioplastics
Paper / Kord Fiber	Paper pulp and a binder
Ricehull	Ground rice hulls and a binder

Container Wall Strength
To determine container strength, containers were filled with potting substrate, placed in a greenhouse and watered once per day. After four weeks, substrate was removed and the force required to punch a 0.2 inch probe through the side of the container was measured. This was done to simulate the force it would take a finger to puncture the container wall.

Plastic had the highest strength followed by paper containers. Cocofiber and ricehull containers were stronger than the remaining containers and of all containers tested, peat, Fertil and Cowpot containers had the lowest wall strengths.

This test is important to determine whether a container possesses enough durability when being handled. The researchers found that if a container’s wet wall strength was less than 2 kg, the containers tended to tear or break and handling became difficult. In this study, all containers had adequate wall strengths except Fertil, peat and Cowpot containers, and thus handling of these containers when wet was difficult and could make them problematic for some growers.

Decomposition of Plantable Biocontainers
Vinca ‘Cooler Blush’ were greenhouse grown for 6 weeks in plantable biocontainers and transplanted into outdoor beds with the biocontainers were left intact on the rootball. After 8 weeks, the level of decomposition of the container was determined and expressed as a percentage of the original dry weight of an unused container.

Cowpot containers had the highest level of decomposition, cocofiber had the lowest and all other containers were intermediate. Variation in decomposition rates are likely due to the differences in container composition. Those made of high cellulose materials, which decompose easily, such as Cowpots, had higher rates of decomposition than those with high amounts recalcitrant materials such as cocofiber. Additionally, nitrogen in the dairy manure used to produce the Cowpot containers may have stimulated the activity of microorganisms and subsequent decomposition rates.

Container strength and biodegradation varied among the different types of biocontainers tested. Fertil, peat and Cowpot containers had wet strengths low enough to make handling difficult. On the other hand, these biocontainers were the fastest to decompose in the landscape. Depending upon the crop, cultural conditions and handling, different biocontainer properties will be more or less important. Plant producers wanting to improve sustainability by switching to biocontainers will need to evaluate which of the properties are the most significant and choose a biocontainer that best fit their needs. For more information on biocontainer physical properties please see Evans, Taylor and Kuehny. 2010. Physical Properties of Biocontainers for Greenhouse Crop Production. HortTechnology. 20: 549-555.

This project was funded by the Arkansas Division of Agriculture, Longwood Gardens and The LSU AgsCenter.

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The Art of Cascade Chrysanthemums at Longwood Gardens

Some of the forms currently being grown for Longwood's 2010 Chrysanthemum Festival

Cascade chrysanthemums have long been at the heart of Longwood Gardens’ annual Chrysanthemum Festival.  Longwood grows specialty mums (Chrysanthemum x moriflorum) that originated in China and Japan and are selected for their ability to create beautiful and lasting forms.  Over the years, Longwood’s amazing show of form and color has been continually modified and refined.  Guests marvel at the captivating shapes and often ask us how we create these wonderful pieces of horticulture.  The following is meant to highlight a little behind-the-scenes action and hint at some of the spectacular forms you will see this November in our Conservatory.

Newly potted chrysanthemum cuttings in January, 2010

At two months old the mums are ready to begin training.

Beginning 15 months before the display date, the design team, in conjunction with the grower, makes final chrysanthemum cultivar choices for the following year.  Stock plants—from which we take all of our final plants—are created in order to bulk up on material.  In mid-December the final plants are started as small cuttings.  We begin heavy

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“Canna” We Save the Canna???

Cannas on the center walk in Longwood's Conservatory

Our cannas are being threatened! Plants all around the world are being infected by viruses that can affect the beauty of the plants, and can eventually lead to death.  Unchecked, this could lead to the end of cannas.  Do I have your attention?  Well, don’t panic because here at Longwood we have some projects underway that will hopefully give new life to the beautiful canna!

Seedling cannas in Longwood's Research Department

Canna x generalis is a staple in the summer garden, adding color, texture, and a tropical feel, and at Longwood they provide critical height in the borders and conservatory. The beauty of the canna inspired Longwood to begin a breeding program in the 1970s. Our program has produced more than 18 named cultivars that have been released into the trade and used here at Longwood.  Some of the cultivars are named after Philadelphia area towns, rivers, and themes such as ‘Lenape’, ‘Conestoga’, and ‘Freedom’.  These plants are compact with flowers that have a self cleaning quality (meaning that the dead flowers fall to the ground instead of hanging on the plant).  In addition to terrestrial varieties, we have also introduced several aquatic varieties.

Aquatic cannas in Longwood's Waterlily Display

The Longwood cannas have been used in our Gardens for many years and have even won awards in England.  Unfortunately, they are not immune to viruses.  Most of Longwood’s cannas have been infected from outside stock that was brought into the Gardens.  This led to the focused effort here at Longwood to produce virus-free cannas.

Three viruses that affect cannas include bean yellow mosaic virus and canna yellow streak vrus, which are members of the potyvirus group, and canna yellow mottle virus, which is a badnavirus.  Potyviruses should not be passed from the parent plant through seeds, and plants grown from seed of potyvirus-infected plants should be free of potyvirus. The canna yellow mottle virus is of special concern because it may pass from parent to seed, which is unusual for viruses.  The symptoms of virus infections in cannas include necrotic veins in the leaves, and streaks of  lighter colors on the petals (instead of a solid-colored healthy petal, the infected petals will look like someone painted them with lighter watercolors).  Eventually, more and more necrotic veins will appear. The leaves will also appear chlorotic. The plant will lose vigor and approach death.  Plants that appear to have a virus should be rogued out and destroyed.

A canna leaf with virus symptoms

A canna Flower with Virus Symptoms

Since most of our Longwood stock had contracted one virus or another, we decided to grow a population of plants from seed in hopes of creating virus-free plants.  A total of about 500 canna seedlings were grown from open-pollinated seeds collected from canna stock on Longwood property.   From this population, we selected ten superior seedlings in 2008 for use and further study.   All selected 2008 seedlings tested negative for virus. These plants were propagated, and we began the process of establishing them in tissue culture. You can see two of these cannas now in the Conservatory: canna #9 is a beautiful medium pink and is planted around the perfume bottle in the center walk of the Orangery; canna #10 is dark pink and is planted in the North East corner of the Orangery.  Canna #9 has been established in tissue culture and is growing nicely.  However, canna #10 is being more difficult or, some may say, stubborn.  It does not grow and multiply in tissue culture as readily.

Another  twelve superior seedlings were selected from the seedling population in 2009. Unfortunately some of these seedlings tested positive for canna yellow mottle virus, which lends evidence that the virus is transmitted through seeds.  We placed the clean plants in the same house with the clean plants from 2008, while the virus-infected plants were isolated. The clean plants will also be established in tissue culture.  Once clean stock is established in tissue culture, it will remain clean.  It can then act as a source of clean plant material in the future.

Canna Isolation

Cannas in general have proven to be finicky about their media in tissue culture—one media does not work for every canna.  When establishing them in culture, each cultivar is placed in several different types of media in hope that they will be happy with at least one of them.  The process itself can take years.  Chrysanthemums can be established and multiplied in culture in a few months.  Cannas can take two years to establish and multiply—only after you find the correct media! If you don’t find the correct media, they may not grow at all. Oh, the patience you must have with cannas!

Canna in tissue culture box

When our selected plants have multiplied sufficiently in tissue culture, we plan to use them here at Longwood.  We also hope that some will be available for purchase at your local garden center, and the canna can be given a second chance.  Currently we have five virus free varieties growing happily in test tubes.  This stock gives us the capability of continuously producing clean crops of cannas.  Many more test tubes hold cannas in various stages of development that may or may not yield clean stock.  The canna cleanup process will take a lot of time and effort, but I think we “canna” save the canna.

If you are interested in learning more about our canna breeding program, come to Longwood on September 7, 2010, when you can join a special tour of our Canna Breeding Program. The tour begins at 1:00 pm and meets at the Exhibition Hall Clock in the Conservatory.

Cannas currently on display in Longwood's Conservatory

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