Contact Us Host an Event 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
1 rating

Monday - July 25, 2011

From: Mohnton, PA
Region: Mid-Atlantic
Topic: Pruning
Title: Cutting back perennials in PA
Answered by: Anne Bossart

QUESTION:

Can you pinch back echinacea in the spring to produce a shorter plant? I have some that get too tall and fall over.

ANSWER:

Yes you can, but not this year.

There are a number of late-summer/fall blooming perennials that can be cut back by half in late spring/early summer.  As a result, they will be shorter and sturdier (less likely to need staking or fall over).  They will also be bushier and more floriferous.

I have had a similar problem in one of my perennial beds and tried it this year on:

Aconitum delphiniifolium (Larkspur-leaf monkshood)

Monarda didyma (Scarlet beebalm)

Phlox paniculata (Fall phlox)

So far, so good ... the monarda is blooming on schedule at a shorter height than usual and the other two seem to be budding.  I am in zone 5 and did it late in May ... you will want to do it a little earlier than that.

Besides these three and your Echinacea purpurea (Eastern purple coneflower), you can also give the same treatment to:

Eupatoriadelphus maculatus (Joe-pye weed)

Physostegia virginiana (Fall obedient plant)

Symphyotrichum oblongifolium (Aromatic aster)

and the tall sedum varieties.

 

From the Image Gallery


Larkspurleaf monkshood
Aconitum delphiniifolium

Scarlet beebalm
Monarda didyma

Fall phlox
Phlox paniculata

Eastern purple coneflower
Echinacea purpurea

Spotted joe-pye weed
Eutrochium maculatum

Fall obedient plant
Physostegia virginiana ssp. praemorsa

Aromatic aster
Symphyotrichum oblongifolium

More Pruning Questions

Non-blooming Tecoma stans in Fredericksburg, TX
June 30, 2008 - We have an esperanza plant purchased last year from Walmart and planted outside before winter. It flowered excellently last year. Just before winter we cut it back to about a foot. So far this summer ...
view the full question and answer

Pruning guidance for Carolina buckthorn from Houston
October 23, 2012 - I have a Carolina Buckthorn in my back patio that I planted in fall 2001. The summer of 2003 the roofers dropped something off the back and broke the top 10-12 inches off. I have tried to train the la...
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

How to Care for a Yucca after Blooming
September 13, 2014 - We just moved into our home and there was an existing yucca plant in the yard and it had bloomed. There was some kind of vine growing in and around it. We tried to clean out the vine but I noticed a l...
view the full question and answer

Flowers for days on end in California
March 30, 2012 - What are some plants or flowers that I can grow "all-year" in California?
view the full question and answer

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