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
2 ratings

Sunday - May 18, 2008

From: Kerrville, TX
Region: Southwest
Topic: Compost and Mulch, Diseases and Disorders, Planting, Herbs/Forbs
Title: Chlorosis in tropical milkweed and asclepias tuberosa
Answered by: Barbara Medford

QUESTION:

I planted both tropical milkweed and asclepias tuberosa. Both are chlorotic and the native milkweed has brown upturned leaves. Could it possibly be too much water? Or what?

ANSWER:

Asclepias curassavica, or Tropical Milkweed, is a native of South America and therefore does not appear in our Native Plant Database. However, here is a Floridata website on it for reference. Asclepias tuberosa (butterfly milkweed) is a native and you can click on the link and read the information on it in our database.

Chlorosis is a yellowing of leaf tissue due to a lack of chlorophyll. Possible causes of chlorosis include poor drainage, damaged roots, compacted roots, high alkalinity, and nutrient deficiencies in the plant. Nutrient deficiencies may occur because there is an insufficient amount in the soil or because the nutrients are unavailable due to a high pH (alkaline soil). Or the nutrients may not be absorbed due to injured roots or poor root growth.

The Asclepias genus usually does not require a great deal of water, but if the soil is not draining well, the roots will be inhibited from picking up the trace elements in the soil, especially iron, and that will result in the plants becoming chlorotic. The major cause of chlorosis is a deficiency of one of the essential micronutrients such as iron or manganese. This deficiency occurs not because the nutrients are lacking in the soil but because they are unavailable due to a high-pH soil. At these higher soil pH levels (6.5 and above) many trees and shrubs are incapable of taking up adequate amounts of iron or manganese. This part of Central Texas has a lot of alkaline soil; however, some compost mixed into the soil or used as a top dressing often will address the problem, providing better drainage, reducing the alkalinity and improving the texture of the soil and permitting access to the trace elements needed.

 

More Planting Questions

Rock under space for Bigtooth Maple in San Antonio
May 20, 2013 - I just got a 10 gallon Bigtooth Maple in Medina TX for my home outside loop 1604 in San Antonio. I hit rock about 7 inches in when trying to plant it..I am entertaining the idea for a raised bed to le...
view the full question and answer

Planting Texas Mountain Laurel seeds in Horse Shoe Bay,TX
July 09, 2012 - I have harvested Texas Mountain Laurel pods and extracted the seeds from the pods. The seeds are characteristic red/orange/maroon. When is the best time and best method to introduce seeds into pots? ...
view the full question and answer

Best time to plant Habiturf in Austin
February 20, 2012 - When is the best time to plant Habiturf seeds?
view the full question and answer

Transplanting and Pruning Callicarpa
August 21, 2014 - I saw the previous question about Callicarpa from the guy in Texas and I have two questions based on the response. In SW Vermont, is late fall still the best time to transplant my Callicarpas? Also, i...
view the full question and answer

Propagation of rain, oxblood, and copper lily bulbs
November 30, 2012 - I have Rain Lily, Oxblood Lily, and Copper Lily bulbs out of the ground, that are putting out some green growth. I would like to plant them soon. Is it okay to plant now and in December, or do I hav...
view the full question and answer

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