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

Friday - June 10, 2011

From: White Oak, TX
Region: Southwest
Topic: Non-Natives
Title: Problems with non-native althea in White Oak TX
Answered by: Barbara Medford

QUESTION:

I have an althea bush that is 2 years old. I have never had a problem with it before but this year only half of it has leaved out and is blooming. The other half has some very small leaves and very small blooms but will not bloom or continue to leaf out. I tried putting some fertilizer on it to help the problem and discovered that ants had made a home in that side of the bush actually in the branches and the roots. Is there any way that I can save it?

ANSWER:

Hibiscus syriacus, Rose of Sharon, formerly referred to as Althaea syriacus, is native to India and China and therefore falls out of our realm of expertise. The Lady Bird Johnson Wildflower Center is committed to the growth, protection and propagation of plants native not only to North America but to the areas in which those plants grow natively. We realize you probably bought the plant locally, but the fact that a plant is sold locally does not mean that is native there or even, in some cases, will survive at all.

There are a number of problems that this plant can have, including leaf spots, cankers, rust, aphids and spider mites. Putting fertilizer on an already stressed plant is never a good idea-the fertilizer pushes the plant to put on new growth when it is just struggling to survive. Also, the fertilizer will encourage  production of leaves, at the expense of blooms. Using a high-nitrogen fertilizer, such as a lawn fertilizer, will only discourage blooms.

We don't believe the ants are your primary problem. Please read this previous Mr. Smarty Plants question involving ants, which turned out to be an aphid problem. An excerpt from that answer:

Ants are farmers and very fond of aphids, but not to eat. They will protect or fiercely defend aphids so they can harvest the "honeydew," exuded by the aphids. That honeydew is a major food source for the ants. On outdoor (and sometimes indoor) plants, ants protect and care for honeydew-producing insects such as aphids, soft scales, whiteflies, and mealybugs, increasing damage from these pests.

What to do about it? Since your plant is non-native to North America we have no information on it in our Native Plant Database. If you eliminate the aphids, the ants will move on to somewhere else they can practice their honeydew farming.   We recommend a good hard spray of water onto the affected plants, which knocks aphids and their eggs off and they can't get back up. The next thing you can do is try to keep the aphids from wintering over in your garden. See this aricle on Controlling Aphids in Your Garden.

If you don't find indications of aphids on your plant, search on the Internet for the other problems that Hibiscus syriacus is known to have and are listed above.

 

 
 

More Non-Natives Questions

Natural fibers for lashing bamboo in weaving
May 07, 2008 - I live in Austin and am looking for plants I can use for weaving fibers, e.g. lashing bamboo for a small project. What plants and parts do you recommend? What resources do you recommend for informatio...
view the full question and answer

Plants for a nursing home resident from LaQuinta CA
July 26, 2013 - I take care of an elderly woman with dementia. She is in a nursing home and she's always LOVES flowers and plants. Do you have any suggestions for potted outdoor blooming plants for the summer in...
view the full question and answer

Non-native vines poisonous from Bakersfield CA
May 17, 2013 - Are pink bower vines and stars and stripes mandevilla toxic to dogs?
view the full question and answer

Why are there gnats in my houseplants?
July 22, 2009 - I have flying brown gnats in my house plants. Can you tell me why?
view the full question and answer

Clearing out non-native Himalayan blackberry
January 25, 2009 - Can you recommend a way to clear an area of Himalayan blackberry? We have cut the canes back but wish to eliminate them completely so that we can replant that area with native plants attractive to wil...
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