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

Sophora seeds to give away
April 13, 2016 - When we moved to TX years ago we bought a mountain laurel so we could have the beautiful purple flowers and were disappointed when the flowers every year were white (with a few purple ones here and th...
view the full question and answer

Leaves turning yellow on Banana Shrub in Eutaw. AL
July 28, 2013 - We have a very large (about 12' tall), very old (probably planted in the early 1900s) Banana Shrub in our front yard. It was very healthy until last year when its leaves began turning yellow and fal...
view the full question and answer

Perennial summer blooming plant for Livonia, MI
May 22, 2009 - I want to find a plant that I can cut back in the fall, will come back in the spring, flower throughout the summer, be a medium size plant, no taller than 48", about 36" in diameter. It would get f...
view the full question and answer

Getting a senna to fill out from Irvine CA
May 30, 2013 - I have a Senna of some kind, started from a seed by a friend. I got it as a small,six in high) seedling. After two years it is now blooming beautifully, but is a single thin stem 4 feet tall with ve...
view the full question and answer

Evergreen shrubs for privacy in Merced County California
September 11, 2009 - Mr. Smarty, A main road will be moving closer to our home in the next two years. A chain link fence will be put in but we would like to start planting now for privacy. We would appreciate any ide...
view the full question and answer

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