Behind the Scenes – Page 14 – My Chicago Botanic Garden

Willow Pruning in the Malott Japanese Garden

If you took advantage of the warm weather last Tuesday and decided to visit the Chicago Botanic Garden, you may have noticed something unusual, especially if you wandered over to the Elizabeth Hubert Malott Japanese Garden.

The Zigzag Bridge was closed for public safety until we could finish pruning.

The sight of horticulturists walking on water was not a hallucination.
In spite of the 60-degree weather, the lake was still frozen and we took advantage of the situation to finish some winter pruning.

The arborists, equipped with the proper safety equipment, are busy pruning the small willow branches.

Though this willow pruning appears very intense, even harsh, it provides airflow into the tree and gives young branches more room to grow. Some of the large, more upright branches are left to provide height. From an aesthetic point of view, this pruning gives the tree significantly more texture, creating clumps that flow into thin weeping branches. As willows can become quite large, pruning also prevents the tree from becoming disproportionately so.

Benjamin Carroll stands on the ice to prune and provide direction to the arborists.

For the past four years, Benjamin Carroll, the senior horticulturist who maintains the Japanese Garden, has been working with arborists from the area to shape up his trees to give them a more traditional appearance. This style first emerged in Japan.

*Seba on the Kisokaido* by Utagawa Hiroshige shows the style we are trying to emulate.

Before this style of pruning was implemented, the willows were pruned to appear mounded. For the first three years of this pruning style, many large branches were cut to drastically change the appearance of the trees. This past year we were able to focus on smaller branches.

A willow prior to pruning this year. — A willow looks different before it was pruned this year.

January is the best time for us to do this because the trees are dormant and the sheet of ice on the lake is fairly thick. Tree dormancy is very important when pruning because nutrient flow is minimal and the wounds made by winter pruning will heal quickly in the spring.

Cleanliness is very important to us, it looks good and reduces debris that could promote disease. — While the arborists cut branches with pole saws and chainsaws, I moved branches off the ice.

The thickness of the ice is also helpful to us because it simplifies cleanup.

After the branches are moved to shore, they’re loaded onto a club car and taken to the mulch pile.

Cleanliness is very important to us because it not only keeps the Garden looking its best but it also reduces debris that could cause disease problems in the future.

Though we look fairly confident walking on the ice, it is important to remember that ice is always dangerous. We always have seasoned professionals and the proper safety equipment nearby.

Goodnight, Roses

Putting roses to sleep for winter

In early November, many of the roses that bloom twice per year (called remontant, or repeat-blooming) were still putting on quite a show in the Rose Garden. Even that late in the season, the garden looked exceptionally lush—canes were tall, bloom was heavy, and November’s cold-but-not-freezing nights kept the last of the season’s flowers going through Thanksgiving.

Finally, early December brought below-freezing nighttime temperatures—and Garden staff jumped into action to put the rose beds “to sleep” for the winter. Now the garden looks entirely different.

The process that our staff uses to prep roses for winter is the same process you can use in your rose garden, too.

Step 1: Prune canes.

While early spring is the major pruning season for roses, end-of-the-year pruning protects the plant from winter wind (canes can whip around and scar each other, and stiff winds can pull long-caned plants out of the ground). Prune out thin or crossing canes to open up the plant, and cut back remaining canes by one-third in height.

Step 2: Clean up leaf litter.

This simple step can prevent major problems later, as leaf litter is a prime source of diseases and pest problems. As you can imagine, we have a lot of leaf litter in a garden with 5,000 roses plants; our truly dedicated volunteers and staff spent two days removing every last leaf from the beds.

Step 3: Mulch.

Mounded up and around each rose plant is a thick layer of mulch (we use well-aged horse manure, but chopped and well-composted leaves work, too). Mulch protects the plants, helps maintain even temperatures, and adds fresh nutrients to the soil. When spring arrives, this extra blanket of mulch will be removed.

And speaking of spring, check out our YouTube video on how to prune climbing roses:

Mumtastic Mums!

The fall mum display at the Chicago Botanic Garden is an annual tradition that requires careful planning and attention to detail. We wanted to let you know what it takes to grow over 13,000 mums each year and train them into interesting shapes and forms.

The first mums you’ll notice are located at the entrance to the Visitor Center. Four 10-foot tall obelisk-shaped mum towers were planted with gold colored mums, named ‘Golden Spell.’ The obelisks are fitted with an internal watering system that allows for easier and even water distribution to the sides of the towers. About 260 plants go into each one of these towers and it takes about 6-12 hours each week to maintain them through the summer months.

Our fall hayracks cascade over the bridge between the Visitor Center and the Crescent Garden. We grow two sets of these to provide blooms throughout the fall season. Each set lasts from 3-4 weeks. This year we grew a yellow anemone type named ‘Megumi’ and a bronze colored daisy type mum named ‘Vernal Falls’. Starting in February, we take all the cuttings for the hayracks from our stock of plants. Fifteen plants go into each hayrack frame and it takes 24 hayracks and 6 side planters to cover the bridge. We spend about 16-20 hours per week training the stems to grow down instead of up. We weigh the stems down with hexagon nuts and spend the summer pinching and trimming the plants to maintain the shape.

PHOTO: Mums being trained to a basket shape.

We also plant 108 giant mum containers for the display in the Esplanade and other gardens. Starting in June, with the help of our summer interns, we spend three days planting about 40-70 plants in each container. We use hanging basket frames to train the mums into a rounded shape. We shear the tops twice during the summer and use growth regulators to keep the growth compact. The last shearing is done no later than July 22. We are constantly feeding the mums and watering every other day to keep them in good health.

Finally, we planted two varieties of cascading mums this year in the Malott Japanese Garden: a white anemone flowered mum, named ‘Snowfall,’ and a yellow mum, named ‘Megumi.’ These mums are trained to cascade down a mesh screen.

Spring Garden Display Preview

We stopped by the Production Greenhouses to see what they are growing for the upcoming spring garden displays. Tim Pollak, Outdoor Floriculturist, said we are growing 66,000 spring annuals and vegetables onsite this year for displays in the ground, in hanging baskets and containers.

Tim explained that the foxgloves you will see in the Circle Garden and Rose Garden were started from seed in October, grown at 42 degrees F for six weeks and brought into the greenhouse in January to grow with long days and warm temperatures to get them to bloom earlier than usual. The lupines you will see in the Heritage Garden and English Walled Garden are two years old and we plan to return them to the greenhouse for many years so they will continue to grow in size. The penstemon you will see in the Circle Garden have been growing for one year to get them to size, then overwintered in a nursery quonset and brought into the greenhouse in January to grow with long days and warm temps to get them to set flowers. Now, they are back in a quonset to slow their flowering until they are planted outside.

We are growing several species of echium (tower of jewels) for displays outside the Visitor Center as well as in the Heritage Garden and English Walled Garden. Most of the plants shown here were started from seed 18 months ago to get them to flower this spring. Echium fastuosum will grow 5-6 feet tall outside the Visitor Center, whereas Echium pininana will grow 12-14 feet tall in the Heritage Garden.

What are you most looking forward to seeing this spring?

View the video on YouTube here.

How to Decorate Gingerbread Houses

Pastry chef Kathy Skutecki shows you how to decorate gingerbread houses like the ones she made for the entrance to the Wonderland Express exhibition. Visit http://www.chicagobotanic.org/wonderland for more information.