Host an Event Volunteer Join Tickets

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?

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
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


Smooth hydrangea
Hydrangea arborescens

More Shrubs Questions

Blue rug juniper native to New Hampshire
March 29, 2009 - Is the blue rug juniper native to New Hampshire? I'm considering it for ground cover near lake in zip 03872.
view the full question and answer

Problems with evergreen sumac in San Antonio
May 03, 2012 - I planted 5 5-gallon (approximately 2 feet tall) evergreen sumac in early January. Since that time they have sprouted out new shoot with new leaves several times - every time the leaves have wilted a...
view the full question and answer

Floristic Quality Assessment program in Texas?
January 19, 2009 - Do you have knowledge of a Floristic Quality Assessment program for Texas such as the ones used in Indiana and Illinois?
view the full question and answer

Can animals eat bottlebrush buckeye without being poisoned?
June 13, 2013 - Can deer, bear and wild turkey and squirrels eat the nuts and leaves from the bottlebrush buckeye shrub without being posioned by it.
view the full question and answer

Plants for full-sun landscape
November 20, 2007 - I live in a very rocky area just outside of Fort Worth, TX. It's taken me all spring, summer & now I'm going into the fall, to landscape just 30 feet in front of my house. The front of the house get...
view the full question and answer

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