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 Herbs/Forbs Questions

Nativity of Salvia coccinea (scarlet sage)
September 14, 2011 - Is Salvia coccinea native to Florida? In wikipedia they say it is native to Mexico.
view the full question and answer

Plants for North Myrtle Beach SC
June 05, 2012 - What plants will do well at North Myrtle Beach, SC that will take full sun with dry soil?
view the full question and answer

Damaged newly planted Gaura in Austin
April 16, 2010 - Hello yet again! This past Friday we attended the plant sale where we got lots of goodies to start a new bed. The plants were all planted on Sunday. All of them are doing fine, even beginning to...
view the full question and answer

Mildew in Phlox paniculata
October 13, 2008 - I planted garden phlox (phlox paniculata) in my front landscaping and it is suffering from mildew. It is wet on that side due to a down spout and it may benefit from being split. Does anyone know of...
view the full question and answer

Mexican sage bushes in Mokena IL
July 12, 2010 - I have two Mexican sage bushes; can they be planted in Illinois and survive the winter?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center