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?


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

Friday - May 10, 2013

From: Flushing, MI
Region: Midwest
Topic: Trees
Title: Fertilizing a Mature Mountain Ash
Answered by: Anne Van Nest


What kind of fertilizer should I use on a mountain ash tree that is 25 years old (or more)?


Congratulations on having a mountain ash that has reached a good mature age. Often mountain ash (Sorbus sp.) are short lived due to insects or diseases. The Yardener.com website has a good information sheet on caring for mountain ash that has good tips. Under fertilizing they say "Mountain ashes are not heavy feeders. They can survive nicely on minimal nutrition. However, it is a good idea to feed mountain ashes in the yard once a year. In the spring sprinkle a handful or two of a fertilizer on the soil under the tree out as far as the reach of its branches (the drip line). The rain will soak it in.” They also have information about fertilizing trees.

The International Society of Arboriculture (ISA) has a good information sheet for mature tree care on their website. They offer many preventative care suggestions and discuss mulching, pruning and fertilizer application.

The Michigan State University has diagnostic services and have posted an information sheet on fertilizing trees and shrubs on their website.


From the Image Gallery

American mountain ash
Sorbus americana

American mountain ash
Sorbus americana

More Trees Questions

Growing pecan and fruit trees near Canyon Lake, Texas
July 07, 2014 - I just bought a property on the north side of Canyon Lake in the Hill Country of Texas. Most of the trees around are cedar, and a few live oak. I know I have seen beautiful Pecan trees as well as seve...
view the full question and answer

Red oak leaves have a swelling along the veins
June 17, 2015 - I have red oaks in my back yard, approx 30 or more have a disease that are wilting the leaves. Looking at the back of the leaf there is swelling along the spines. I've gone to one nursery in town ...
view the full question and answer

Encouraging branch growth of live oak trees in Austin
February 10, 2009 - I recently had an elm tree cut down that was crowding out 2 live oak trees in my front yard. The oaks have no branches on the sides that were next to the elm. The elm stump is still there. I need to ...
view the full question and answer

Native Texas Hill Country nitrogen-fixing plants
June 07, 2006 - Please help me find a listing of native (TX Hill Country) nitrogen-fixing plants.
view the full question and answer

Alder native to Central Indiana
May 30, 2006 - I am trying to find out whether there exists a plant named Alnus rugosa. I bought a plant recently that said Speckled Alder, Alnus serrulata (rugosa), but have been unable to determine if this is a c...
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.
© 2015 Lady Bird Johnson Wildflower Center