Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
12 ratings

Wednesday - March 17, 2010

From: Little Chute, WI
Region: Midwest
Topic: Shrubs
Title: Native trees or shrubs for containers on roof in Wisconsin
Answered by: Nan Hampton

QUESTION:

Looking for native trees/shrubs to be planted in containers on a flat roof w/south-southeast exposure. Gets pretty warm in the summer and pretty cold in the winter. How big would the container have to be?

ANSWER:

First, let me refer you to our article, Container Gardening with Native Plants.  You will see in the article that the recommendation for the size of the pot is: 

"Select a container that will accommodate the full sizes of the plants it will house. It should provide ample root space and have a substantial base to offset top-heaviness (both visually and in terms of stability)."

Winter weather in Wisconsin, however, presents an addtional consideration for the size of the pot you can use.  I believe you can handle the summer heat as long as you pick plants that are happy growing in full sun and you give them adequate water.  However, the winters are another matter.  Roots in a container will not have the same protection from freezing that roots buried in the ground will have.  With container plants you will need to move them to a protected environment to protect their roots as the winter temperatures drop well below freezing.  Consequently, you will need to select plants that fit into containers that you will be able to move to a protected place. You can read advice on preparing container plants for winter weather in the article, Maintaining Winter Gardens in Gladwin, MI, from the National Gardening Association.

Below are shrubs that are Wisconsin natives that grow in full sun.  If the your area is in shade (less than 2 hours sun per day) or part shade (2 to 6 hours of sun per day), you can find recommendations for other plants in our Wisconsin Recommended list.  You can use the NARROW YOUR SEARCH option to limit the list to only 'Shrubs' by choosing that selection under GENERAL APPEARANCE.

Actaea rubra (red baneberry)

Amorpha fruticosa (desert false indigo)

Cornus racemosa (gray dogwood)

Dasiphora fruticosa ssp. floribunda (shrubby cinquefoil)

Physocarpus opulifolius (common ninebark)

Symphoricarpos albus (common snowberry)

Shepherdia canadensis (russet buffaloberry)

Yucca filamentosa (Adam's needle) and here is more information.

Here are photos of the above plants from our Image Gallery:


Actaea rubra

Amorpha fruticosa

Cornus racemosa

Dasiphora fruticosa ssp. floribunda

Physocarpus opulifolius

Symphoricarpos albus

Shepherdia canadensis

Yucca filamentosa

 


 

 

More Shrubs Questions

Pruning and deadheading rosa rugosa while blooming
August 01, 2008 - Can you prune the dead flowers and branches of rosa rogosa while it is still blooming?
view the full question and answer

Hill Country natives for a hedge
June 01, 2006 - Can you recommend a "hedge type" bush to use in lieu of a fence along the road in the San Antonio region? My whole back yard is planted with Hill Country natives and I would prefer to keep the the...
view the full question and answer

Plants for full sun and clay soil in NY
May 06, 2008 - We live in upstate new york( zone 5) with full sun and clay soil. What flowers/flowering shrubs would be successful in this environment?
view the full question and answer

Small shrub with thorns for Austin
February 08, 2010 - I'm looking for a shade-tolerant 2-3' shrub with thorns, native to Texas (ideally central Texas) - an alternative to Barberry? Does such a plant exist?
view the full question and answer

Planting time for non-natives in Irving TX
February 07, 2012 - Have dwarf nandinas and two lorapetalums that I want to transplant. Can I do it now February 6th 2012?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.