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

Sunday - June 15, 2008

From: Charleston, WV
Region: Mid-Atlantic
Topic: Diseases and Disorders
Title: Decline in willow tree in West Virginia
Answered by: Barbara Medford

QUESTION:

I planted a willow tree about three years ago and it was progressing just beautifully with full leaves this spring in a nice green color. We staked it back about three weeks so it would grow straighter. This week I have noticed all of the new baby leaves are yellow in color. I cannot find anything wrong with the tree (such as bugs, holes, splits) I am so worried it is dying, is there anything I can do to help it, or can it be normal for young leaves to be yellow? I love this tree and have always wanted one since I was a child. I would love to be able to help it.

ANSWER:

First, we need to define some terms. There are 55 species of the Genus Salix, all willows, in our Native Plant Database. We are going to assume (hope) that yours is a native species, and not Salix x babylonica or weeping willow, which is a hybridized non-native, a somewhat weak, short-lived tree that is very susceptible to disease and insect damage. We found three willows that are native to West Virginia and chose Salix nigra (black willow) as our subject. It is considered a very good example of the genus, which provides erosion protection and shade, as well as sheltering wildlife. As nearly as we can determine from this USDA Plant Profile of the location of Salix nigra (black willow) in West Virginia, Kanawha County is easily in the range where the tree grows naturally.

Yellowing leaves are usually the result of chlorosis, or lack of chlorophyll, in the leaf. It does you no good to know what causes it, if you don't know how to prevent it. We will present you with some possibilities and maybe you can determine for yourself the cause and cure. Sorry, we haven't kept up with weather in West Virginia this year, but has it been flooding or at least raining a great deal in the area where your willow lives? The Genus Salix is considered to have intermediate tolerance for flooding around its roots, especially in the growing season. The water on the trunk and roots over an extended period of time can lead to yellowing of the leaves (chlorosis), defoliation, and reduced leaf size. Young trees may be more intolerant of flooding than more mature trees. How about the urban air pollution in which your tree grows? Ozone and sulfure dioxide in the air can enter the tree and inhibit leaf function, again producing chlorosis, which means it is probably not a very good "street tree." Chlorosis is also caused by inaccessibility of trace elements in the soil, especially iron, to the roots. This is sometimes caused by poor drainage, meaning too much water is around the roots, or impacted soil from foot traffic or construction.

Sadly, you can do very little about air pollution or flooding, if that proves to be the case. If the tree is in what you consider to be a poor location, it may still be small enough to consider moving it. But not in the Summer! Our favorite time for transplanting is late Fall or very early Spring, when the tree is semi-dormant. Read this article from about.com on How To Transplant for the practical how-to and techniques that are recommended. You can spend the time from now until transplanting season determining if the tree location really is the problem and, if so, where else on your property it would be in a better situation.


Salix nigra

Salix bebbiana

 


Salix discolor
 

More Diseases and Disorders Questions

Black rot at center of Agave from Clovis CA
May 12, 2013 - We have some beautiful variegated "Green & Cream" Agave plants in our cactus garden. One in particular has done quite well for several years and is the largest, about 18" tall & across, it has neve...
view the full question and answer

Sap oozing from non-native Chinese pistache in San Antonio
September 07, 2011 - I live in San Antonio, and my chinese pistache is exuding copious amounts of a sticky sap from old trim sites and from the trunk itself. The tree is about 12 years old and has been healthy up until no...
view the full question and answer

Need help diagnosing a problem with Bur Oak in Plano, TX
April 28, 2010 - I planted a bur oak 8 or 9 years ago. It has grown beautifully until this year. When opening, the leaves are very small (a couple inches) and there are lots of seeds (catkins?). I would hate to los...
view the full question and answer

Moth using Agarita as its larval food in New Braunfels, TX
March 27, 2009 - What moth uses agarita as its larval food? It is a perennial problem that can nearly defoliate the specimen and severely limit its flower production.
view the full question and answer

Watering oaks in Houston, TX.
June 07, 2011 - Our yard (Real County, TX.) has many oak trees. We never water these trees, but I wonder if you recommend watering during this extreme drought. The trees look very stressed and are covered in ball m...
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
© 2014 Lady Bird Johnson Wildflower Center