Rent Shop Volunteer Join

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

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

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

Queen Palm Fertilization in Arizona
March 06, 2012 - I placed standard Miracle Grow in a root feeder device and inserted into the ground around all of my Queen Palms. Why have they taken a turn for the worse (furled tips on all new branches) Can you ov...
view the full question and answer

Problems with non-native navel orange
October 03, 2008 - Hello Green Guru, Question: Why hasn't Navel Orange Tree grown or sprouted new branches? It's 3 years old and is about 5 feet tall and has remained this size. It hasn't grown at all. It only ha...
view the full question and answer

Shade tolerant plants for privacy from Larchmont NY
April 19, 2014 - Love your site! We have a 4'x4'x50' stone wall, full sun, with a planting bed 30"H by 24"D. We're looking for privacy, so a hedge with pruning is needed. We have looked at Ilex Crenata (8'),...
view the full question and answer

Non-native bulbine damaged by freeze
March 15, 2010 - Our Texas bulbine were hit hard this year. The tops are dead, not sure if any roots are still alive. Should we trim them back to the dirt; if roots are still alive, will they emerge again via root s...
view the full question and answer

Changing color of non-native crape myrtles
August 02, 2008 - How do you change the color of a bloom on a crape myrtle tree?
view the full question and answer

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