En EspaŅol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Wednesday - March 18, 2009

From: Newburgh, NY
Region: Northeast
Topic: Pruning, Seasonal Tasks, Herbs/Forbs
Title: Cutting back achillea in New York
Answered by: Barbara Medford

QUESTION:

Last summer I planted three gorgeous hearty achillea with flat, yellow tops, about 3 feet high or more each, in my sunny garden. But after they were done flowering, I left those very pretty brown stems and heads right where they were. It's still cold up here in upstate New York. Should I cut them back and if so, how far?

ANSWER:

You can certainly cut back the perennial Achillea millefolium (common yarrow) in the fall or early spring. It was a good idea to leave the stalks and heads where they could add some interest to the winter garden. Care of most herbaceous perennials suggests cutting back the stalk after it dies back, and cleaning up the area around the plants to prevent mold, insects overwintering and disease. We like to leave about a 6-inch stalk when we trim back perennials to mark their place so, when the first leaves start coming up from the roots, you will not think it's a weed and pull it out. The yarrow in our Image Gallery are all white, but we found this Magnolia Gardens website with a picture of the "Moonshine" cultivar in yellow. 

 

From the Image Gallery


Common yarrow
Achillea millefolium

Common yarrow
Achillea millefolium

More Pruning Questions

Failure to bloom of Texas Mountain Laurel
April 15, 2008 - My +/- 4 yr old Tx. Mountain Laurel, has never bloomed. It is in full sun. I sometimes (minimal) fertilize it. I've pretty much planted it and let it grow. Its been pruned back last year when som...
view the full question and answer

Pruning of Hamelia patens, Firebush
June 23, 2006 - I have a Hamelia Patens (Fire Bush) it says it will grow to 12 feet high and 5-6 feet across. Can I keep pruning it to about 5 feet without damaging the shrub?
view the full question and answer

Spring care for Garrya ovata from Pflugerville, TX
February 24, 2014 - Hello again, Mr. S-P, I planted a Mexican silktassel in April 2012 (purchased at the WFC). It has done well, but the leaves are bronzed and splotchy from this winter's freezes. All the stems are...
view the full question and answer

Cutting back perennials in PA
July 25, 2011 - Can you pinch back echinacea in the spring to produce a shorter plant? I have some that get too tall and fall over.
view the full question and answer

Tree removal from Austin
November 18, 2013 - Unfortunately we need to cut down a Spanish oak (11" diameter, over 50 feet tall) that is leaning against our upper story deck (if it falls, the roof, deck, and steel supports may be crushed). A lim...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2015 Lady Bird Johnson Wildflower Center