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

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 Herbs/Forbs Questions

Small, flowering, evergreen plants for hillside in Austin.
October 27, 2007 - I have a steep, dry hillside measuring approximately 4 feet high by six feet wide. I want to plant low growing, evergreen, flowering plants across the bed that will flower as long as possible, and thr...
view the full question and answer

General information on native Fendlers sandwort (Arenaria fendeleri)
December 19, 2005 - I am trying to locate any general information on Fendler's Sandwort. Any help will be greatly appreciated.
view the full question and answer

Non-native daylilies for steep hill in Manassas VA
April 25, 2013 - Would like to plant steep hill w perennial flowering plants like daylily. The daylily farm said this would work great but not sure if we should lay landscaping fabric and poke through holes to plant ...
view the full question and answer

Native Texas Plants for a Terrarium
October 08, 2014 - I have a 55-gallon aquarium that I would like to make into a terrarium. Are there any Texas native plants that would do well in the limited artificial light of the tank? The plants should be of varyin...
view the full question and answer

Pruning for Spring
January 21, 2007 - When should I cut back (and how far should I cut back) the following plants in order to promote growth in the spring: Salvia gregii, Salvia leucantha, Ruellia (Mexican petunia), Plumbago, Sku...
view the full question and answer

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