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  • November 15, 2018 11:33 AM | Anonymous

    By Danielle Green

    The AZH Program Committee is now accepting proposals for presentations at the 2019 AZH Annual Conference

    hosted by Philadelphia Zoo August 25-28, 2019.

    What makes an AZH Conference special is presentations from horticulture professionals like you! The challenges and obstacles that we face every day lead to solutions and success. Share these with your zoo horticulture colleagues by speaking in the program, creating a poster, or participating in a panel discussion.

    Everything that you need to know to be an AZH presenter is here. 2019 AZH CALL FOR PRESENTATIONS

    Chris Dailey, AZH Program Chair


  • October 23, 2018 3:17 PM | Anonymous member (Administrator)

    If healthy ecosystems are what we desire, we must embrace predators. There is no way around it. Because of their meat-based diets, predators can have serious effects on plant diversity. Generally speaking, as plant diversity increases, so does the biodiversity of that region. It's not just large predators like wolves and bears either. Even predators as small as spiders can have considerable impacts on not only plant diversity, but ecosystem processes as well. Before we get to that, however, we should take a moment to review some of the background on this subject.

    The way in which predators mediate plant diversity falls under a realm of an ecological science called top-down ecosystem controls. In a top-down system, predators mediate the populations of herbivores, which takes pressure off of the plant community. It makes a lot of sense as a numbers game. The fewer herbivores there are, the better the plants perform overall. However, ecology is never that simple. More and more we are realizing that top-down controls have less to do with fewer herbivores than they do with herbivore behavior.

    Herbivores, like any organism on this planet, respond to changes in their environment. When predators are present, herbivores often become more cautious and change up their behavior as a result. Such is the case of grasshoppers living in fields. Grasshoppers are incredibly numerous and can do considerable amounts of damage to plant communities as they feed. Picture swarms of locusts and you kind of get the idea.

    Given the choice, grasshoppers will preferentially feed on some plants more than others. Such was the case when researchers began observing grasshopper behavior in some old fields in Connecticut. The grasshoppers in this study really seemed to prefer grasses to all other plants. That is unless spiders were present. In this particular system lives a spider known as the nursery web spider (Pisaurina mira). The nursery web spider is an effective hunter and the fact does not seem to be lost on the grasshoppers.

    In the presence of spiders, grasshoppers change up their feeding behavior quite a bit. Instead of feeding on grasses, they switch over to feeding on goldenrod (Solidago rugosa). Although the researchers are not entirely sure why they make this shift, they came up with three possible explanations. First is that the goldenrod is much more structurally complex than the grass and thus offers more places for the grasshopper to hide. Second is that goldenrod fills the grasshoppers stomach in less time thanks to the higher water content of the leaves. This would mean that grasshoppers had more time to watch for predators than they would if they were eating grass. Third is that the feeding behaviors of both arthropods allows the grasshopper to better keep track of where spiders might be lurking. It is very likely that all three hypotheses play a role in this shift.

    It's the shift in diet itself that has ramifications throughout the entire ecosystem in question. Many goldenrod species are highly competitive when left to their own devices. If left untouched, abandoned fields can quickly become a monoculture of goldenrod. That is where the spiders come in. By causing a behavioral shift in their grasshopper prey, the spiders are having indirect effects on plant diversity in these habitats. Because grasshoppers spend more time feeding on goldenrods in the presence of spiders, they knock back some of the competitive advantages of these plants.

    The researchers found that when spiders were present, overall plant diversity increased. This is not because the spiders ate more grasshoppers. Instead, it's because the grasshoppers shifted to a diet of goldenrod, which knocked the goldenrod back just enough to allow other plants to establish. It's not just plant diversity that changed either. Spiders also caused an increase in both solar radiation and nitrogen reaching the soils!

    In knocking back the goldenrod, the habitat became slightly more open and patchy as various plant species of different shapes and sizes gradually established. This allowed more light to reach the soil, thus changing the environment for new seeds to germinate. Also, because goldenrod leaves tend to break down more slowly, they can have significant influences on nutrient cycles within the soil. As a more diverse set of plants establish in these field habitats, the type of leaf litter that falls to the ground changes as well. This resulted in an overall increase in the nitrogen supply to the soil, which also influences plant diversity.

    In total, the mere presence of spiders was enough to set in motion these top-down ecosystem effects. It's not that spiders eat more grasshoppers, it's that they are changing the behavior of grasshoppers in a way that results in a more diverse plant community overall. This is a radically different narrative than what has been observed with examples such as the reintroduction of wolves to the greater Yellowstone ecosystem yet the conclusions are very much the same. Predators have innumerable ecosystem benefits that we simply can't afford to ignore.

    Photo Credits: [1] [2] [3]

    Further Reading: [1] [2]

  • September 23, 2018 9:27 AM | Anonymous


    Event (Click for Details)


    18 – 22 Sept 2018 EAZA Annual Conference Athens, Greece
    27 Sept 2018 PlantNetwork: Betula identification and cultivation Ness Botanic Gardens, Nr. Chester
    29 Sept 2018 Wildlife Gardening Forum: New findings in Wildlife Gardening Science Trinity Centre, Bristol
    2 October 2018 Introduction to the Science of Algae Cambridge University Botanic Garden
    3 Oct 2018 Working and Designing with Trees Barcham Trees, Cambridgeshire
    12 Oct Valuing and Managing Veteran Trees Killerton House, Devon
    16 Oct2018 Reinventing Pruning: Implementing the New North American Pruning Standards and Best Management Practices Barcham Trees, Cambridgeshire
    20 Oct 2018 Fungi Ecology and Identification part 1 (beginners) Wildwood Trust, Herne Bay, Kent
    24 Oct 2018 Valuing and Managing Veteran Trees Warwickshire
    31 Oct – 1 Nov 2018 SALTEX Trade Show NEC, Birmingham
    10 Nov 2018 Fungi Ecology and Identification part 2 (Intermediate) Wildwood Trust, Herne Bay, Kent
    20 Nov 2018 Tree Pests, Diseases and Fungi Warwickshire
    21 Nov 2018 Climate Change – Building Resilience in the Arboricultural Sector Wokingham, Berkshire
    21 – 22 Nov 2018 Identifying Conifers Cambridge University Botanic Garden
    17 – 18 May 2019 The Arb Show Westonbirt Arboretum, Gloucestershire
    21 – 25 May 2019 RHS Chelsea Flower Show Royal Hospital, Chelsea, London
    9 – 10 June 2019 Open Garden Squares Weekend Across London
    2 – 7 July 2019 RHS Hampton Court Palace Garden Festival Hampton Court Palace, East Molesey, Surrey
    17 – 21 July 2019 RHS Flower Show Tatton Park Tatton Park, near Knutsford, Cheshire
    17 – 21 Sept 2019 EAZA Annual Conference Bioparc Valencia, Spain
  • September 07, 2018 9:57 AM | Anonymous


    Seed Your Future is helping more people see what we already know—horticulture is cool!!



  • September 03, 2018 12:21 PM | Anonymous


    Keeping plants merely alive in zoos is no small feat. Pressures of collection animals (including time-and-space pressure of browse production), non-collection animals, and the visiting public often make for sparser-than-hoped landscapes.

    What’s a horticulturist charged with transporting visitors to far away places to do? In Denver, we’ve started growing specialty annuals and perennials for display in key places to help captivate visitors with as small an impact to staff resource as possible. Ideally, a chosen plant will be quick to grow and ostentatious in presentation. If the plant is available to purchase as seed, so much the better, as seeds are typically budget-friendly and provide greater flexibility in propagation timing. (Highly appreciated if you’ve ever had the joy of receiving a shipment of cuttings on a Friday afternoon.)

    This year we introduced Puya mirabilis to our plant palette for the first time; it’s been well worth our efforts. Perhaps the fastest of bromeliads to grow from seed; the spiny rosettes of this Patagonian native produce flowers in their second year, allowing for a summer sowing to produce blossoms the following growing season—provided an overwintering spot of at least 20°F can be provided. We grew our plants in a 50–60°F greenhouse through the winter and they quickly achieved flowering size.

    Upon setting them out in early spring (around March 15), they showed some signs of cold stress after a 22°F night but rallied brilliantly; and though tasted by rabbits they proved by-and-large pest resistant in the extreme. Their spiny (but not-too-spiny) leaf margins also made them unattractive to unwelcome human attention. They are tolerant of dry conditions; our specimens made a great addition to a garden with somewhat inhospitable southern exposure.

    In early August, the rosettes produced dramatic 5-6 foot inflorescences from which dangle waxy green three-inch flowers offset by fuzzy bluish calyces. At least for some photographers, a more attractive subject than the nearby flamingos!

    John Murgel, Denver Zoo

  • August 23, 2018 12:28 PM | Anonymous


    Sacramento Zoo Plant ID Signage  Michaele Bergera, Sacramento Zoological Society

    Background:    In 2014, the Sacramento Zoo’s director passed away unexpectedly. The interim director requested that I replace the plant identification signs that were in place at the time and had them removed. Since then, I have been working to get them replaced. The cost of replacing the signs for our entire collection of plants and trees was too high for us to do all at once, so I was asked to prioritize the list. In the meantime, the zoo went through rebranding, another change of leadership, and unfortunately the project was put on hold during each transition. Thanks to the Wendy Andrews Cultivation Grant, in both 2017 and 2018, I was able to start labeling plants once more! The Sacramento Zoo has a new director, and I am happy to say that he seems very supportive of the horticulture department and our efforts to properly identify plants and educate the public!

    The purpose of this project was to create and install identification signs to educate/inform zoo visitors about the plants and trees in our collection. By providing this signage, we hope to show our guests that the Sacramento Zoo values our plant collection as well as our animal collection. Plant Identification signs add to our guest experience by providing an additional educational opportunity. Thanks to the funding provided by the AZH Wendy Andrews Cultivation Grant, I have been able to label an entire garden area.  The plant ID signs will be viewed by over 500,000 guests that visit the Sacramento Zoo annually.

    The signs for this project were installed in early August, in an area that we refer to as the Zoo’s Backyard. It was originally designed to be a demonstration garden for “river-friendly” landscaping and consisted mainly of California native plants. I thought that the signs would have a greater impact if they were placed in one area as opposed to being spread out throughout the zoo. Since the installation of the signs, I have noticed visitors slowing down, taking pictures, and discussing the plants! The full amount of the grant was used to purchase seventy 2” x 4” signs, one 5” x 8” sign, and the stakes to mount them on. The total cost of the project was $1043.25. Thank you to the Association of Zoological Horticulture for your continued support.

  • August 20, 2018 12:33 PM | Anonymous



    The time has arrived! I am packing my bags, placing meetings and lunches in my calendar, and emailing friends and members to see when and where we can find time to catch up over busy conference week. What a week it looks to be: The program committee has done an excellent job arranging some fabulous sounding presentations; The board is set to get down to business with an item-packed agenda; the committees have all submitted their reports to get ready for annual meetings; our host has put together an amazing, informative and action packed itinerary. I am officially excited to start the conference and cross Assiniboine Park off my bucket list!

    Starting off the conference, the 2018 board members will meet together, some for the last time before the new members are on-boarded later in the conference. I would like to thank Nancy Tarver for her 5 years of service to AZH as a board member and officer. I would also like to congratulate and thank Lance Swearengin and Donita Brannon for their continued service as directors-at-large. Finally, please help me congratulate and welcome Dianne Weber as your newly elected director-at-large. I challenge and encourage all members to explore the possibilities of running for office or board assignment in next year’s election. It is an extremely rewarding experience and opportunity to enhance your commitment to the field.

    I am also excited to meet our newest members and first time conference attendees. Conference is the forum for us all to learn from each other’s challenges and successes, share our knowledge and experiences that have the power to unify us together when it can feel a bit alone inside of your own organization, and to reinvigorate your passion for what you do.


    When it comes to business; whether a zoo, an aquarium, an art or history museum, a Fortune 500 company, or a main street coffee shop, it’s about people. People, our guests, are our target market…our “brain capital”…the only way we change the world together. It’s people that you work to educate, to inspire, to create memories for. Our work and our landscapes have the power to do all of that. How do you tell your stories for conservation in your institutions? If your story does not include your flora with your fauna, then you might consider some editing. It is your passion and voice for plant science that engages a holistic message of conservation for zoos and other living museums. Collectively, through AZH, our voice is strong and loud! Do not forget about the other collectives that support you too; your animal care staff, your leadership, other hort organizations, your PEOPLE!

    That about wraps up my rant for the quarter. Hopefully I got you thinking and anxious for some energetic conversations over conference. For those unable to attend this year, feel free to rant back over the Discussion Forum on the website. Also, don’t forget that the program committee works extremely hard to post the proceedings from each conference on the website, so if you miss the opportunity to be there in person, you are still able to have a glimpse on-line.

  • August 19, 2018 12:36 PM | Anonymous


    For at least ten years, scientists have been noting changes in wild koala populations that appear to be linked to the quality of their only food source: eucalyptus. Increases in CO2 levels are causing eucalyptus to grow faster. But faster is not always better. This rapid growth produces foliage that is poorer in nutrients and higher in toxic tannins. Koalas have evolved to be able to process these compounds within certain ranges. These shifts in nutritional content are leading to cases of malnutrition in the animals, and secondarily to higher mortality due to predation and highway collisions as the animals seek out new food sources. Nearly ten years ago, the International Union for the Conservation of Nature published concerns over this phenomenon in 2009, and subsequent studies are underscoring the gravity of these circumstances. There are troublesome implications for many other plant–animal relationships including humans and our heavy global reliance on a small number of plant species. Recent studies suggest that rising CO2 levels are leading to nutritional changes in rice and wheat. —Sandy Masuo

    Read more about climate change and nutritional changes in rice and wheat:


    For more information about climate change and koalas:



  • August 16, 2018 12:37 PM | Anonymous


    AZH promotes the contributions made by horticulture to the success of zoos and the establishment of effective habitat exhibits. To support this mission, AZH established the "AZH Internship Program" to assist zoos in accomplishing projects that enhance the zoo experience and bring attention to the importance of horticulture.   The $1500 stipend is to advance special horticulture related projects and introduce zoo horticulture to a new generation. The funds are not intended to be used for routine garden or grounds maintenance.  More information about the program is found here - https://azh.org/azh-internship-program/

    The 2018 AZH Internship Program Award was awarded to Amy Yarger at the Butterfly Pavilion in Westminster, CO.  This is the second award for Amy and the Butterfly Pavilion from this program.  Details on the program are below.

    Plant Collections Internship 2018


    The purpose of the Plant Collections 2018 internship is to provide an undergraduate horticulture or museum studies student with a thorough training and hands-on practice in the field of planning, designing, and evaluating plant collections in a zoological setting. The Plant Collections intern will work closely with Butterfly Pavilion’s horticulture director to formalize and present the botanical collections plan for Butterfly Pavilion’s new facility, the Center for Invertebrate Research and Conservation (CIRC), which opens in 2021.

    Goal of Project

    The public plant collections at CIRC will offer immersive and engaging natural experiences for our guests and the community at large, while providing ample food and shelter for our captive invertebrates, as well as native invertebrate and vertebrate wildlife. The collections will focus on the flora of tropical, desert and Rocky Mountain environments. The plant collections plan will be updated in 2018 in order to prepare for the design of the new plantings, the acquisition of new species, the transplanting of existing specimens and best management practices. This plan will guide us in assessing risk, identifying sources for plants and evaluating the performance of plants in exhibits and the landscape.

    Objectives for 2018 Plant Collections Internship

    Butterfly Pavilion horticulture internships currently offer undergraduate, graduate and postgraduate students in the plant sciences a semester’s opportunity to gain experience in public garden management, habitat restoration and greenhouse management. This new internship would be a 15-week program (August – December) with involvement in the planning process from the design phase to the acquisition phase.

    • The student will collect and analyze data about performance of the current collections and provide recommendations for transferring current holdings to the new facility.
    • The student will compile information for the propagation or acquisition of new plant specimens for the entire CIRC facility.
    • The student will collaborate with the horticulture director on creating planting layouts for the tropical, desert, Rocky Mountain biome and outdoor gardens and create management plans for each.
    • The intern will complete and present an independent project in the subject of plant collections during that time.


    Action Steps Timeline Staff
    Work with planning team on concept and exhibit  interpretation January 1 – September 30 2018 Horticulture Director, Architects
    Intern onboarding August 20 – September 1, 2018 Volunteer Manager
    Evaluation of current collections: tropical and pollinator gardens August 20 – October 15, 2018 Plant Collections Intern w/ training and support from Horticulture Director
    Concept and design of new exhibits and gardens: desert and Rocky Mountain August 20 – October 15, 2018 Plant Collections Intern w/ training and support from Horticulture Director
    Independent project proposal submitted September 1. 2018 Plant Collections Intern w/ training and support from Horticulture Director
    Compile best practices for transplantation, propagation, acquisition and management October 1 – December 1, 2018 Plant Collections Intern w/ training and support from Horticulture Director
    Intern midterm evaluation October 15, 2018 Horticulture Director
    Independent project presented to staff and volunteers December 10, 2018 Plant Collections Intern
    Final evaluation December 15, 2018 Plant Collections Intern, Horticulture Director
  • August 15, 2018 12:39 PM | Anonymous


    Did you know that AZH has produced online courses available through San Diego Zoo Global Academy?

    Browse & Toxic Plants and Responsible Water Use are available online via this online learning platform.  IPM course is still in construction but we hope to have that up and running soon.  Instructions to access the courses (and many others) is found below.

    The Association of Zoological Horticulture Collaborative Learning Environment® provides an interactive peer-to-peer learning environment to allow you to communicate, spread ideas, share resources, discuss topics and learn in a safe environment.

    Registration Instructions for AZH Courses

    There are multiple ways to access the AZH courses. You may take the course through the AZH private academy (e-learning site), your institutions private academy, or through San Diego Zoo Global Academy (SDZGA). Included below are instructions for each scenario. We diligently worked through each avenue, but complications may arise. You may contact the CollaborNation helpline (CypherWorx) at (888) 685- 4440.

    For AZH members whose organizations have a private academy (elearning site): You can access the course through San Diego Zoo Global Academy. Once you join your private academy, you may need to request access to SDZGA from CypherWorx – (888) 685-4440.

    1. Login to your Once in, click on the drop down tab in the top right corner of your screen titled “Select a Site.” You will see a drop down list – select the San Diego Zoo Global Academy.
    2. On the top menu bar click on Course Catalog.
    3. Scroll down to the “Browse by Category” menu on the right side. Click on the AZH category to pull up the course. You may also enter the course title into the Search Catalog
    4. Click on the “Learn More”
    5. Click on the “Add to Cart”
    6. Enter the AZH member coupon code. AZHMEMBER50%
    7. Continue the checkout process.

    For AZH members who are not members of an academy (private elearning site): You can join the AZH Academy at https://collabornation.net/login/azh or through the link at http://azh.org/azh-course-registration/ (click on Registration Instructions)

    1. Log in to your AZH account.
    2. Register into the CollaborNation AZH eLearning site. There is a $25.00 joining
    3. On the top menu bar click on Course Catalog.
    4. Find the “Browse and Toxic Plants” course in the listing.
    5. Click on the “Learn More”
    6. Click on the “Add to Cart”
    7. Enter the AZH member coupon code. AZHMEMBER50%
    8. Continue the checkout process.
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