En Español

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

Wednesday - August 06, 2008

From: Wichita Falls, TX
Region: Southwest
Topic: Non-Natives, Pests, Edible Plants
Title: White spots on Hibiscus leaves
Answered by: Barbara Medford

QUESTION:

My hibiscus trees have white spots or splotches on the leaves. What is it and what can I do to get rid of it? Also, the birds are eating my tomatoes faster than i can grow them. I've used the owl & snake tricks which work about a week & then they're back eating again. What do you suggest?

ANSWER:

Again, we have to figure out what plant we are talking about. There are literally hundreds of plants typically referred to as "hibiscus", some annual, some perennial. There are some native hibiscus and many that are non-native, but all belong to the mallow family, so hopefully even if we pick the wrong one to discuss, the same advice will apply. Since you refer to hibiscus "trees" we believe that what you have is a Hibiscus syriacus, native to Asia, and often called Rose of Sharon. There are other mallows called Rose of Sharon, as well, adding to the confusion. A synonym to the current name is Althea syriacus, and lots of people have what they call altheas.

Since the Hibiscus syriacus is non-native to North America, we have no information on it in our Native Plant Database. At the Lady Bird Johnson Wildflower Center, we urge the use of plants native to the area in which they are being used, because they are already adapted to the environmental conditions there and thus will require less fertilizer, water and maintenance. However, we have done some research and will try to answer your questions on the leaf spot. This USDA Forest Service website on Rose of Sharon will give you general information on care for the plant as well as pests and diseases. It is hardy in Zones 5 to 8, and Wichita Falls is in Zone 8, according to the USDA Zone Hardiness Map.

Aphids may cover leaves with sticky honeydew. Over-fertilizing increases aphid infestation. However, we believe what you are asking about is bacterial leaf spot; the only treatment we found for that was to pick off and destroy the infected leaves. Don't leave fallen leaves or blooms on the ground as they may harbor the bacteria.

Now, on to your tomato question. Once more, we are talking non-native plant. Most food plants are either non-native to North America or so intensively hybridized that they bear little resemblance to the original form. Tomato, Solanum lycopersicum, is a member of the Solaneaceae or Nightshade family, closely related to tobacco, chili peppers, potao and eggplant. It is native to Central and South America from Mexico to Argentina. With reference to keeping birds out of them, if we could devise a fool-proof method to keep all the little beasties that love tomatoes, too, off of them we would be zillionaires. See this excellent Texas A&M Horticulture site on Tomato Questions. One which addresses your question is quoted below:

"Tomatoes should be supported. Whether you cage or stake them is personal preference. Regardless of the method, plants with foliage and fruit supported off the ground will produce more than unsupported plants. Caging has several advantages. It involves less work than staking. Once the cage is placed over the plant there is no further manipulation of the plant - - no pruning, no tying. The fruit are simply harvested as they ripen. In many areas, staking and pruning of the plant to a single or multiple stem results in sunburn when the developing fruit is exposed to excessive sunlight. Other advantages of caging over staking include protection of fruit from bird damage by more vigorous foliage cover and less fruit rot. Caged tomato vines produce more fruit of a smaller size, but staked and tied plants produce less fruit which mature earlier yet are larger."

 

More Non-Natives Questions

Problems with non-native weeping willow in Villanova PA
July 03, 2009 - My weeping willow (6 years old,80+ft tall),up until this year used to be full and healthy. Last year I trimmed the lower portion of the trunk by cutting off the low hanging branches, but this year so ...
view the full question and answer

Bulb identification
December 10, 2009 - My pinecone ginger (Zingiber zerumbet), my white ginger (Hedychium coronarium) and my cana lilly roots were all accidently put in the same box and now I can't tell which is which. Is there some sort ...
view the full question and answer

Black fungus on non-native ixora from Palm Beach Gardens FL
January 29, 2011 - We have 7-8 ixora plants that are side by side and all have developed a black fungus or substance on them. The substance is not only on the plant, but has spread to the wall they are adjacent to. Ca...
view the full question and answer

Care for non-native indoor plants
October 20, 2007 - My cousin in Pa. asked me to see how to care for 2 plants in the winter. The first is a Voo Doo Lily and the second is a Bengal Tiger plant. If you would please help I would be able to pass it along...
view the full question and answer

Identification of Cryptomeria japonica for homeowners association
May 09, 2007 - Good morning. We are wondering if Cryptomeria japonica trees can fit under the term "pine like". We used the term pine like when asking for our home owners associations approval and we put in a Cr...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center