pruning – Page 2 – 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:

Forcing Branches to Bloom Indoors

Heather Sherwood, Senior Horticulturist at the Chicago Botanic Garden, shows us how easy it is to cut flowering branches and bring them indoors for early blooms this spring!

Winter Pruning with Dave Cantwell

As Horticulturist Dave Cantwell demonstrates, winter is a great time to prune trees and shrubs. Follow his tips to make all the right cuts. Want to learn more? Tim Johnson, Director of Horticulture teaches “Pruning Principles” each March, before trees come out of dormancy. For more information on this and other classes, visit the Joseph Regenstein Jr. School at chicagobotanic.org/adult_education.