Explore Plants

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
    
 

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

Brown leaves on Burr Oak from Dripping Springs TX
October 05, 2013 - We have recently planted a 15 gal. burr oak in an correct hole with great soil and plenty of watering in. We have noticed some brown leaves. Should we be worried?
view the full question and answer

Problem with baldcypress tree
May 27, 2011 - Two of my three 20 year old Bald Cypress trees appear to have leafed out but are now brown in parts of the tree. The brown area is at the tops of the trees which are probably 40 ft. high. They were...
view the full question and answer

Elimination of live oak adventitious sprouts in San Angelo TX
July 28, 2009 - Live oak sprouts. The main tree was removed several years ago and we still have the sprouts coming up in the yard. How do we stop this?
view the full question and answer

Looking for yellow bottlebrush (Callistemon sp.) and native substitutes
February 14, 2008 - I have been looking for years for a yellow bottle bush. It is identical to the red but is yellow. there are several varieties, but the one i want is just like the red one in appearance. I live in Flor...
view the full question and answer

Growing Magnolia trees in Palm Desert, CA.
October 02, 2012 - Will magnolia trees grow in the Palm Desert/Indio, CA area?
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.