Heritage Garden Viola Pyramids

My summer intern, Melanie Jensen (now a senior studying horticulture at Southern Illinois University), has always wondered how botanic gardens put together their impressive seasonal displays. In fact, she was so intrigued by them that she did her final presentation—a graduation requirement for the Garden’s horticulture internship program—on the complexities and challenges of preparing these displays.

To say the work is complex and challenging is almost an understatement. Sometimes our work here seems like magic. Overnight, the Garden can transform from spring to summer or summer to fall. Yesterday there were spring troughs, summer palm trees, or fall mum towers in the Garden. Today, there is something completely different. Yes, it does seem like it happens just like that, perhaps with the snap of a finger. But behind the scenes, for months or even years before most visitors get to see a display, a team is already hard at work making it happen.

The Viola Pyramids are currently on display in the Heritage Garden
The Viola pyramids are currently on display in the Heritage Garden.

Melanie and more than 50 other staff and volunteers had a front row seat this summer to help me create this fall’s signature display in the Heritage Garden—the Viola pyramids, which are now on display. The pyramids themselves are really just a set of simple flowers presented in a very unique way. The story could end right there, but what I think makes this display fascinating to people like me and Melanie (and hopefully to you, too) is the astonishing amount of work it takes to get the pyramids from concept to finished product.

The Garden began working on this project more than a year ago, when outdoor floriculturist Tim Pollak and I were brainstorming on how we could use the pyramids in another display. Last used about five years ago, the pyramids have traditionally been used as a summer display component, planted with two cultivars of Alternanthera. Pressed to take a fresh approach to the pyramids, we settled on the idea that they would make a great fall display. We considered using mums (too fragile, and many growing challenges) and Verbena (not frost-tolerant enough for fall), and concluded that Viola were our best option. Others agreed.

Saying we are creating Viola pyramids is the easy part. Actually doing it is a completely different story, and it’s a testament to great project planning and teamwork at the Garden.

Here’s what it took:

1. Our production team grew 6,400 Viola plants, half orange and half purple, so they were ready for planting into the pyramid structure by early August. The pyramids are 9 feet wide at the base, and 10 feet tall at the apex. 

Panels lined with landscape fabric
Panels lined with landscape fabric

2. In the meantime, Melanie and I led the team to prepare the pyramid frames. Working in the nursery, our first step was to attach landscape fabric to the front face of the pyramids using hundreds of zip ties. Landscape fabric helps hold the soil and the plants in the frame. We had to be very careful that the fabric covered every nook and cranny of the frame. If not, soil would leak from the frame, and it would undermine the integrity of the entire planting space.

Filling the panels with custon blended planting media
Filling the panels with custom-blended planting media

3. Next we custom-blended special planting media, using lightweight potting soil and perlite. The pyramids retain water differently at their tops versus their bottoms, so we changed the composition of the media throughout the frame to accommodate this variance. Near the top of the pyramid we used a heavier, more water-retentive blend of about 70 percent soil and 30 percent perlite. At the bottom, where there is a risk that the pyramid could become waterlogged, we created a lightweight mix that was about 30 percent soil and 70 percent perlite. You can see in the picture how the soil/perlite composition changes from top to bottom.

panel with hose
Soaker hoses weave throughout the frame

4. Most of the time we will water the pyramids with a hose and water nozzle, but sometimes we need to give them a deeper soaking, especially on hot and sunny days. To help with that, we weaved soaker hoses throughout the frame so that we could water from the inside out.

Intern Melanie Jensen prepping the panels
Intern Melanie Jensen prepping the panels

5. To make the pyramids lighter (each individual panel weighs about 500 pounds—meaning each pyramid weighs 2,000 pounds), and to reduce the amount of soil and perlite needed, we stuffed sheets of foam insulation into the bottom of the frame. A mesh screen secured all of these materials inside the frame.

Deadheading the viola panels
Deadheading the Viola panels

6. Time to plant! We cut tiny holes into the landscape fabric and inserted a Viola plant. As we planted, we also pinched and deadheaded each and every Viola. During the critical first few weeks of growing in the pyramids, the Viola plants need to spend their energy developing roots and spreading foliage to cover the entire frame, rather than producing flowers. Removing all of the flowers is a hard thing to swallow, but it’s really for the best long-term interest of the display.

(Incidentally, the cut flowers were put to good use, donated to our Roadside Flower Sale team. Pressed flowers are sold at their annual sale, with proceeds supporting Garden initiatives, including generous funding for the horticulture department.)

PHOTO: Giant planted triangles of blooming violas in the nursery.
The Violas doing what they do best: blooming again

7. The original plan was to leave the Viola plants simply to grow as-is under the care of our great production team until they were display-ready in mid-September. However, Mother Nature had other plans. The weather caused the Viola to grow faster than expected, and by late August it became clear that we would need to do another round of deadheading. Staff and volunteers again converged in the nursery for two days of meticulous work removing every flower head and seedpod from the display. It was a lot of work, and a little disconcerting to again make a beautifully colorful pyramid all green and flowerless, but it was an important task so the Viola could flower prolifically later into the season.

PHOTO: A team of 12 people (and a forklift driver) place a panel in the Heritage Garden.
Lifting a panel into place in the Heritage Garden

8. Time to move to the Heritage Garden! It took 15 strong groundskeepers, some extra machinery and ropes, a lot of creative thinking, and 1½ days of hard work to move the pyramids from the Nursery to the Heritage Garden. Come by and take a look!

I often like to break down the numbers for a project, because it articulates the scope of work in a way that words cannot. So, here are some numbers for this project: Over one year of planning, more than 50 people involved, 6,400 plants used, and more than 500 hours of labor to get the job done. Yes, 500 hours!

It seems like a lot of work—and it is—but I hope that everyone who sees the display takes away something uniquely personal to them. Perhaps it sparks your creativity on how to use simple plants in unique ways. Maybe seeing something new and special triggers your passion for plants and horticulture, either as a hobby or as a career. Sometimes the display will draw your attention to a part of the Garden that you never explored before now. Or maybe you like it just because it looks pretty cool. It’s even O.K. if this display just isn’t your thing: artistic choices are very personal. Whatever your take-away is, however, my hope is that we can use this display and others like it to engage you in a conversation about plants and to help you connect to the Garden in an exciting new way. That makes 500 hours of work worth it for me.

Enjoy!


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Time to Uncover the Rose Garden

Who doesn’t love a warm winter blanket? With unseasonably cold temperatures continuing into early April, that blanket has been especially welcome this year. If you are like me, though, you just can’t wait for that first day when you lose the covers and open the windows. It is that breath of fresh air that tells us summer is just around the corner.

PHOTO: A view of the roses near the education building.
Roses under a warm winter blanket of mulch.

Our Krasberg Rose Garden is ready for its breath of fresh air, too. All winter, many of our roses have been under their warm blanket of composted horse manure. Compost protects roses from the harsh winter winds and freeze and thaw cycles that can be deadly to many cultivars.

As the hours of sunlight increase and daytime temperatures get warmer, however, we need to start inspecting our roses for signs that it is time to remove the compost and prepare the roses for the beauty yet to come.

The process is fairly straightforward. In late March, or whenever we have had several warm days with limited risk of a killing frost, we use our hands to carefully remove the thawed compost from around a rose bush. We need to inspect several bushes because some areas of our Garden thaw and start actively growing earlier than others.

PHOTO: A rose with new spring growth.
New growth from the base of the plant.

We look for yellow, bright green or reddish growth around the base of the plant — these are new rose canes. If we do not see any new growth or if new growth is still very small, we may cover the roses for a few more days. The warm compost encourages rose bushes to break dormancy.

However, if we see new growth and it is an inch or longer, then is it time to completely remove the compost and let the canes grow freely. The sooner this new growth begins to photosynthesize in the sun, the healthier and stronger your plant will be the rest of season. Remember that this new growth is very fragile, so we use gentle care when removing the compost.

PHOTO: Rose before Pruning
Look for black canes that indicate they are dead.

Once we remove the compost, our team then prunes the canes for optimum health. We first remove any cane that is black or brown — these are dead or dying — and anything that looks diseased.

From there, we prune the shrub until it has five or six healthy, large canes that are at least the diameter of a pencil. The pruning should result in an open center, with the top bud on each remaining cane facing away from the center of the plant. The open center maximizes the amount of sunshine and air circulation within the plant — important components to plant growth and disease prevention.

We also take time to frequently disinfect our pruning tools as we work through this late-winter chore. Tools can easily transfer diseases from one rose shrub to another, so sanitation is very important. Mix a solution of 10 percent rubbing alcohol or bleach and 90 percent water in a spray bottle to spray on your tools.

PHOTO: The final rose after spring pruning.
After pruning, the remaining canes look healthy.

By taking a few simple steps like these right now, the rose bushes will be on their way to beautiful blooms in June. Now that’s a breath of fresh air.

You can learn more about rose care with a class at the Joseph Regenstein, Jr. School of the Chicago Botanic Garden. Click here to see what classes are currently available.


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Creating Hypertufa Troughs at the Garden

One of my signature projects at the Chicago Botanic Garden is designing and building the hypertufa troughs for the Heritage Garden spring display. While our greenhouse staff spends their winters growing the unique and beautiful plants that we feature in the troughs, another team is hard at work making the troughs.

PHOTO: Troughs finished and curing.

PHOTO: Heritage Garden troughs from May 2011 display.

Hypertufa is a simulated stone container that is durable in all weather conditions, but lighter-weight than solid stone or concrete. Our trough style, which is rectangular with a distressed finish, is designed to look like vintage livestock feeders that you might imagine aging for generations in the English countryside. 

Making troughs is a heavy and dusty job, but the result is a unique and lasting piece of garden artistry. Here is how we make them at the Garden: 

Step 1 

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Create a wooden frame with an open top and bottom. We build it so we can easily take it apart in Step 6. Line the interior of the frame with heavy-duty plastic sheeting so the concrete does not stick to the frame. 

Step 2 

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Mix 1 part Portland cement, 1/3 part peat moss, and 1/4 part coarse perlite. We add water until the wet concrete slowly falls off our shovel. 

Step 3 

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We pour about 2 inches of concrete into the bottom of the frame. 

Step 4 

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Place another large sheet of plastic on the inside of the frame. Add a 4-inch layer of sand on top of this sheet of plastic. 

Step 5 

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Between the two sheets of plastic, start pouring in more concrete to form the side walls. We try to make the walls about 2 inches thick, making sure they are as even as possible and have no air pockets. As the walls get taller, we keep adding sand on top of the second sheet of plastic. The sand supports the walls until the concrete hardens. Fill concrete to the top of the frame, making sure the support sand is also at the same height.

Step 6 

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After the concrete sets but is not completely dry (6-18 hours, depending on its consistency in Step 2), we remove the wooden frame and plastic.

Step 7

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We then distress the trough to give it a weathered appearance. We use a variety of tools to do this, including hammers, chisels, and wire brushes. This year we even used a power washer. Once the trough is distressed, we drill drain holes and let the concrete completely cure for several weeks. Once cured, it is ready for our spring display!

You can buy pre-made hypertufa containers, but this is definitely a project you can do at home for a lot less money and in a design style that is uniquely your own. Be creative. Add pebbles, shells, or beads to give your trough a little extra flair. Pigment in the mix can give it a color that better matches your décor. Adding more perlite or peat moss will make your trough lighter and give it a slightly different texture (but also makes them a little more fragile, in our experience). Leave the exterior of the trough smooth, rather than distressed, for a more formal or modern look. Lining the mold or frame with leaves (especially those with prominent veins or patterns) is another fun look for the troughs.

When we have a little bit of hypertufa mix left over at the end of our projects, we also like to make unique containers from simple molds that we find around the workshop. An upside down garbage can lid makes a nice birdbath mold. An old plastic bowl can be the perfect shape for a windowsill herb garden. I have even used an old box to make a hypertufa boot tray—who doesn’t need one of those?!  Silly or serious, there is no limit to your hypertufa container options.

PHOTO: Heritage Garden troughs from May 2009 display.


©2013 Chicago Botanic Garden and my.chicagobotanic.org