Rent Shop Volunteer Join

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
Not Yet Rated

Tuesday - June 18, 2013

From: Magnolia, TX
Region: Southwest
Topic: Pruning, Shrubs
Title: Pruning Ageratina havenensis from Magnolia TX
Answered by: Barbara Medford

QUESTION:

I planted a Eupatorium havanense last year here in the last sandy finger of the piney woods; it gets full sun in a well-drained raised bed, where it flowered well. I pruned it fairly close, and it came through the mild winter without any extra watering. It has been putting out blooms, one or two branches at a time, since late February. Should I be pruning back the branches that have bloomed so as to guarantee enough new growth for it to bloom all over in the autumn, or should I be glad it bloomed at all?

ANSWER:

This plant appears in our Native Plant Database as Ageratina havanensis (Havana snakeroot); Eupatorium havanensis is an older name, now considered a synonym.  As you can see from this USDA Plant Profile Map, it grows somewhat west of Montgomery County, and we are not sure the soils would be similar. However, if you are growing it, it must be okay there.

From our webpage on this plant:

"White mistflower provides late summer and early fall color. Blooms best and appears bushier if severely cut back each winter."

That keeps you from deciding whether to cut back the present blooms in hopes of more blooms later. It should continue to provide color until early Fall and then can be pruned back hard in November to January. Perhaps the extra blooming is the result of more rain and lusher soils in your part of the state.

 

From the Image Gallery


Shrubby boneset
Ageratina havanensis

Shrubby boneset
Ageratina havanensis

Shrubby boneset
Ageratina havanensis

More Shrubs Questions

Evergreen thorny bush for California
May 01, 2010 - I need to find an evergreen thorny type bush, shrub or tree that will grow with about 3-4 hours of morning sun only. Prefer CA native, inland/semi coastal. Purpose: To provide a deterrent for "tag...
view the full question and answer

Need suggestions for landscaping along a creek in Lenoir, NC
July 25, 2011 - I live in Lenoir, NC and would like to landscape my creek bank that is about 90 feet long and is 200 feet from my house. I thought about evergeen bushes maybe rhododendron; some grasses; a few trees ...
view the full question and answer

Do female possumhaws require male to bloom?
January 02, 2009 - Do female possumhaws require a male nearby to bloom? I've read that about yaupon hollies, but not possumhaws specifically. Thanks.
view the full question and answer

Deer Resistant Roses and Fruit Trees in NC
April 20, 2015 - Hello, I am planning a house on Lake Gaston in North Carolina (to be built) and will need to establish a new garden on the cleared lot. I would like to focus on native plants, but I love a cutting ga...
view the full question and answer

Why is cedar pollen so heavy this year?
January 08, 2011 - Dear Mr Smarty, Is this year a heavier than normal year for cedar pollen?? If so why?
view the full question and answer

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