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

Thursday - December 13, 2007

From: Evansville, IN
Region: Midwest
Topic: Shrubs, Trees
Title: Rhododendrons Hydrangeas in Indiana
Answered by: Candace Fountoulakis

QUESTION:

I live in very southern Indiana. Our home faces west and at the front of our home I have planted three rhododendrons. The furthest south is growing well the two to the north not so well. All three have bloomed only once,(the second year) with only a few blooms each. They have been there about 5 years. Large trees filter the late afternoon sun. Also, I have planted three hydrangeas on the north side of the house within 2 feet of the foundation, also in afternoon shade. A huge chestnut tree filters much of the sun and a big old grainery that sits on the north side of the house blocks most of the sun. I have not provided acid due to the acidity of oak leaves and I assume chestnut leaves. Can you help me with these two beautiful plants. I am not opposed to moving them if need be but need recommended species for the areas that they are located in now.

ANSWER:

Rhododendrons and hydrangeas both require light, well-drained soils but don't appreciate drying out. They also need an acidic soil, with a pH of 5.5 being ideal. A soil test of the areas where your shrubs are planted will determine if the plants will ever thrive. Amending soil whose pH is not low enough to suit these types of plants is not a reasonable long-term solution. A loose but deep mulch with no other competition from plants other than the trees would also help these shrubs. The foundation can add to alkalinity problems as well as cause iron chlorosis. The soil test would also indicate this if samples were taken from that area. I don't know what effect the grainery would have other than to cast shade or perhaps indicate compacted soil in the area that would inhibit root growth.

If your soil tests determine that the pH is not in the range that these shrubs prefer, I would suggest some similar blooming native shrubs that would do well and bloom in the conditions you describe. I have attached links to these plants so that you can see how beautiful these native shrubs could be.

Hydrangea arborescens (wild hydrangea) (PHOTO BELOW) Cornus racemosa (gray dogwood)

Cornus sericea (redosier dogwood) Itea virginica (Virginia sweetspire)

Viburnum dentatum (southern arrowwood) Viburnum opulus (European cranberrybush)

 

From the Image Gallery


Wild hydrangea
Hydrangea arborescens

More Trees Questions

Identification of tree or shrub in Massachusetts
May 16, 2013 - Good morning, We are in Zone 5 and have a tree/shrub I cannot identify in the backyard of our new home. Tall (6')and growing, green stems,and when the stems are broken the branches smell of lemon o...
view the full question and answer

Note on pond over oak roots from Round Rock TX
December 23, 2012 - Thanks very much to Barbara for answering my question about the live oaks - covering parts of their root systems with a pond. Your answer inspired discussion, and we changed our pond plan and moved th...
view the full question and answer

Drought-Tolerant Trees for South-Central Texas
February 09, 2010 - I would like to replace two Golden Rain Trees with native ornamentals. They should be highly drought tolerant and should not exceed 25 feet in height. They will need to be tough since they will get ...
view the full question and answer

Trees for Parker, Colorado that will not harm horses
March 21, 2009 - we are searching for trees that will grow well in Parker Colorado and not be poisonous to our horses
view the full question and answer

Theory for live oak shoots from Austin
August 25, 2011 - More on preventing suckers from coming up around live oaks in Austin. I too have been puzzled - why some live oaks have shoots, and not others. Posting here says different varieties have suckers. ...
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