Contact Us Host an Event Volunteer Join

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
2 ratings

Saturday - October 03, 2015

From: Austin, TX
Region: Southwest
Topic: Non-Natives, Herbs/Forbs
Title: How to Deal with Leggy Artemisia 'Silver Mound'
Answered by: Anne Van Nest

QUESTION:

I have two Artemisia (I think 'Silver Mound') in full sun in West Austin. They have been happily growing there for the past 10 or so years. Both were hard-hit by last winter's cold weather and did not recover well this summer. I did give them a hard prune in early spring (which I have done probably bi-annually to these plants) and neither grew vigorously this spring and summer. Both are leggy, and neither leafed out at the base and interior of the plant. The weather this year was weird - a particularly cold winter with the first hard freeze in October and an unusually wet spring followed by a very dry summer. Is there anything I can do to re-invigorate these plants? Do Artemisia have a lifespan, or will they grow forever?

ANSWER:

Artemisia, like many other perennials do have a general lifespan and will become less vigorous as each year passes. You will also notice that the plant will get woodier as it ages. It is important to divide many perennials every 3-4 years so they keep producing vigorous new shoots. With Artemisia, take a sharp spade and slice through the clump removing the older center portions. Keep the younger, more vigorous parts of the plant from the outer perimeter of the clump.

Julie Ryan in her book "Perennial Gardens for Texas" says that 'Silver Mound' (a cultivar of non-native A. schmidtiana) is very fine-leaved and creates soft mounds of misty, cloud-like foliage. It is not usually invasive. Seldom over a foot in height, it makes an excellent border or rock garden plant. The middle of the clump tends to die out, but well-drained soil, allowing ample room for each plant, and trimming plants back before they bloom help prevent this.
Artemisia are not set back by the heat of late summer except in high humidity: the combination makes them prone to rot.  She also writes that it likes well-drained soil and does better in poor, sandy soils than rich ones.

So, for next year, prune them somewhat hard again in the early spring and perhaps divide them and replant the more vigorous sections at that time too.

 

 

More Non-Natives Questions

Lifespan of non-native weeping cherry tree
September 17, 2008 - What is the lifespan of a weeping cherry tree? Thanks.
view the full question and answer

Growing kudzu in Las Vegas NV
April 18, 2013 - Hi Mr. Smarty Plants, I have a question about a known invasive species that I know you advise against, but I feel my situation may be different enough that it's worth asking about. Yes, I'm talk...
view the full question and answer

Non-native, invasive, poisonous Chinese yam
October 16, 2005 - I found a vine in my yard [central Indiana] which I believe is Dioscorea oppositiflora and I wanted first to confirm my identification and second to find out about edibility [especially of the airborn...
view the full question and answer

Saving non-native sempervivum from accidental weed killer application from Nashville TN
June 15, 2012 - How to save a 'Live Forever' plant that had weed killer put on it by mistake.
view the full question and answer

Problem with non-native Houttuynia cordata (chameleon)
January 30, 2012 - I have a Houttuynia cordata chameleon plant in a clay pot. My zone is 9b and my yard is partial sun. Up until January, it was thriving. Now, it is dead. I think the cold killed it. I kept it moist at ...
view the full question and answer

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