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 Compost and Mulch Questions

Will recycled tire mulch harm butterfly larvae?
December 05, 2012 - I discovered orange butterfly larva in the hardwood mulch under my Turk's Cap. Will it harm the larva if I switch over to recycled tire mulch?
view the full question and answer

Native plants to provide nitrogen for compost in Houston
March 27, 2010 - I leave my clippings on the lawn so I don't have enough 'green' for my compost. I'd like to plant an unobtrusive area with some native that I can mow on a monthly basis. The area is in partial...
view the full question and answer

Transplanting honeysuckle bush in Illinois
April 18, 2009 - Want to transplant 3 honeysuckle shrubs 10 to 12' tall this month, although not the best time. Please advise.
view the full question and answer

Plants to grow under elm tree in Amarillo TX
May 01, 2014 - I have a large elm tree and I can't get seem to get anything to grow under it. I was wondering if there are any shade-loving groundcovers that you would recommend (have tried English Ivy, hostas, an...
view the full question and answer

Flowering vine for trellis behind fountain in Anaheim Hills CA
June 05, 2010 - We are looking for a flowering vine to plant on a trellis surrounding a water fountain. The fountain splashes leaving the soil constantly wet. We have tried numerous vines, but they all die due to t...
view the full question and answer

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