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
1 rating

Wednesday - May 02, 2007

From: Robbinsville, NJ
Region: Northeast
Topic: Pruning, Herbs/Forbs
Title: Should black-eyed susan (Rudbeckia hirta) plants be cut back
Answered by: Nan Hampton and Joe Marcus

QUESTION:

I have black-eyed susan plants that were beautiful last year and flowered for a long time. Do they need to be cut back and if so, how much?

ANSWER:

It isn't really necessary to cut back Rudbeckia hirta (blackeyed Susan); but if you will deadhead them (i.e., remove the fading flowers before they set seed), it will prolong their flowering period.

 


Rudbeckia hirta

 

 

More Pruning Questions

Replacing non-native boxwood in Austin
October 03, 2011 - I have a large maze garden, possibly boxwood, originally planted in the 1950's, in Austin, Texas. About 1/3 of it has died out, probably due to drought, heat and age. Should I attempt to replant ju...
view the full question and answer

Lack of Blooms and Low Hanging Limbs on Mountain Laurels
August 06, 2014 - My mountain laurel didn't bloom this year but has a few hard pods on it. It is 9 ft tall but very top heavy with most growth low. I need to prune it a lot at the bottom because it has branches hangi...
view the full question and answer

Yaupon sprouts from Bennettsville SC
May 29, 2013 - I have Yaupons in a flower bed and they have too many shoots to pull up, can I spray them with roundup and not kill the bush and what strength should I use?
view the full question and answer

Do yuccas die after blooming?
October 11, 2010 - We have a blue yucca which was planted 2 years ago and is just now blooming with a tower of white flowers. Will the entire plant die after blooming as the century plants do? If so, is there a way to s...
view the full question and answer

Tool for removing live oak root shoots in Gonzales TX
August 09, 2010 - I've read your answer to live oak root shoots. You said to get rid of them by going 2 to 4 inches below the surface and cutting them. What tool is best for this shoot removal? I'm getting very tir...
view the full question and answer

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