En Español

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

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
1 rating

Thursday - July 01, 2010

From: Springfield, IL
Region: Midwest
Topic: Compost and Mulch, Soils
Title: What is composted mulch from Springfield IL
Answered by: Barbara Medford


I love the look of hard wood mulch. It is my understanding that this wood mulch that is so readily available in bulk and bags is not "composted mulch". I have been told that this type of mulch pulls iron away from my plants causing them to look yellow. What exactly is composted mulch? Is there such a thing as composted wood mulch? I want the look that wood mulch adds to my trees and perennial beds. Thank you for your time.


We agree, the look of shredded hardwood mulch is very attractive. It is of greatest benefit in that it protects the roots of your plants from heat and cold. When you put it into your garden, it will begin to decompose "in place" and become an enriching amendment to the soil. This is why you usually need to replenish mulch about once a year or so.

We can remember some discussion a few years ago about mulches pulling nutrients from the soil, but I think that was referring to chipped wood from tree trimmers. It is slow to decompose and does need some help from the material in the soil. We have personally nurtured a compost pile of mostly fallen oak leaves, of which we had a lot, adding water and cottonseed meal for nitrogen and stirring the pile for oxidation. It took at least a year to achieve the level of composting we liked, but we certainly used it as mulch. If you don't have the room or the inclination for a compost pile, you would be better to use the composted mulch you can purchase. However, we have also put 2 to 3 inches of commercial shredded hardwood bark on gardens with good soil and not felt any need to supplement the nutrients. 

This is one of those things that is as much personal taste in gardening as anything else. Read these two articles and form your own opinion. 

Agresource Using Compost as Mulch to Increase Soil Nutrient Level, Microbacterial Activity and Plant Growth. 

Bear Path Farm Compost as Mulch


More Soils Questions

Blooms on Desert Willow withering quickly in Rockwall TX
July 15, 2010 - Why do the blooms on my Desert Willow dry up and wither away in one or two days?
view the full question and answer

Seeding the banks of a large pond
October 18, 2011 - I have a 2 acre surface pond that is mostly a hard clay bank all around. The water level is way down and I will begin filling it very soon. I need to somehow being affordable, plant something or thing...
view the full question and answer

Stress on Goldenball leadtrees from Austin
June 07, 2014 - I know of two separate instances where young Goldenball Lead Trees (leucena retusa) have shown symptoms of defoliation and a bleeding of white sap from sores that have developed on the bark. The first...
view the full question and answer

Growing rabitteye blueberries in Phenix City AL
January 18, 2013 - What type soil is needed to grow rabbiteye blueberries?
view the full question and answer

Failure of highbush blueberry plant to produce in New Hampshire
July 25, 2008 - One of my highbush blueberry plants completely stopped producing. What can I do to revive it?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center