Native Plants

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Friday - May 10, 2013

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

QUESTION:

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

ANSWER:

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