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

Tuesday - July 12, 2011

From: Southampton, NJ
Region: Mid-Atlantic
Topic: Pruning, Shrubs
Title: Pruning smooth azalea in NJ
Answered by: Anne Bossart

QUESTION:

I have a Smooth Azalea growing in my woods. It was verified by the Master Gardeners of Burlington County New Jersey. It's 12 feet tall and lanky. Can it be trimmed in hopes of thickening up? If so, any tips on trimming it?

ANSWER:

What a great find!  I am sure the Master gardeners can give you pruning advice as well, but yes, with careful pruning you should be able to sculpt your shrub and thicken it to a degree.

Rhododendron arborescens (Smooth azalea) is a deciduous azalea which means that it can tolerate (and in the north, require) more sun than its evergreen relations.  If it is not flowering well, its lankiness could be as a result of not enough light.  You don't mention how thick your woods are.

If you decide to prune it, there are two things you must remember: never cut back more than one third of the plant in a growing season, and pruning stimulates growth.  The one third rule means that you can cut back all the branches one third or you can prune one third of the branches to the ground.  The pruning stimulates growth rule means that wherever you cut, that is where new growth will appear.  That is why you sometimes see shrubs that have been sheared to a globe or square shape that are green only on the surface of the plant and have crazy shoots sticking out all over.

So examine your plant carefully and before you make each cut, try to picture how the plant will look without that branch and also realize that exactly where you cut it is where the new growth will appear.

Check out this video on YouTube and watch a demonstration of rejuvenation pruning on some large deciduous azaleas.  That is; one year they cut back one thrid of the branches to the ground and new branches grew from ground level, the second they cut another third and the final year they cut out the last third.  This makes the plant seem juvenile again.  Note that the plants they are demonstrating on are growing in an open, sunny area.

I would also recommend David Joyce's book: Pruning and Training Plants.  It is a great reference for doing all sorts of pruning and it has diagrams.  I am a big believer that a picture is worth a thousand words so it will likely be more helpful than my description.

 

From the Image Gallery


Smooth azalea
Rhododendron arborescens

Smooth azalea
Rhododendron arborescens

Smooth azalea
Rhododendron arborescens

More Shrubs Questions

Natural location of Ceanothus impressus in California
May 21, 2006 - Where is Ceanothus impressus 'victoria' native? I need as specific as you can. Thanks much.
view the full question and answer

Poverty plant overgrown in Austin
June 06, 2012 - We have a poverty plant that is too big for its space in our yard. We like it and want to keep it. Can it be transplanted easily? What about pruning it.
view the full question and answer

Wound from non-native date palm thorn Naples FL
November 12, 2012 - Was trimming my pygmy date palm when a frond fell and a thorn pierced my rubber gloves and stuck me in the web of skin between my thumb and forefinger. Did not see a broken thorn but area where struc...
view the full question and answer

Specimen evergreen for sun in Central Texas
August 28, 2010 - I'm soliciting suggestions for a specimen plant for a new garden we're building. It will be planted in a 3' square raised (18") Limestone bed. It will be full sun, Western exposure, and relative...
view the full question and answer

Need shrubs to replace Mountain Laurel beside above ground pool in San Antonio, TX.
August 08, 2012 - We are getting rid of a Mountain Laurel because it is 5 ft. away from my above ground pool I want to plant at the base of the pool about 20 inches away some nice evergreen. Do you have any suggestio...
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
© 2014 Lady Bird Johnson Wildflower Center