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
5 ratings

Monday - April 21, 2008

From: Atlantic Beach, NY
Region: Northeast
Topic: Soils
Title: Plants for acid soils and coffee grounds for the soil
Answered by: Barbara Medford

QUESTION:

Please tell me what plants & flowers need acid soil and are coffee grains good to make soil acid?

ANSWER:

Once upon a time, people took their used coffee grounds outside to a shady spot and buried them. This encouraged earthworms to show up, because the grounds help to hold moisture in the dirt. Sadly, the people doing this were not doing it for the good earthworms can do for gardens, but for bait! That same principle does hold true, however, when you are preparing potting soil and need some acidity in it. Everybody knows coffee is acidic, and your stomach will remind you of that if you drink too much. So, you recycle the leftover grounds from your morning cuppa into an acid-producing, moisture-holding additive to potting soil. Plants that need an acidic soil to do well are rhododendrons (including azaleas), blueberries and blackberries, hydrangeas and many types of evergreens and conifers. Most other plants, including vegetables and fruits, need a neutral to slightly alkaline soil. Some gardeners who are growing acid-loving plants suggest using the coffee grounds as a side dressing to the plants in the ground.

 

More Soils Questions

Need suggestions for planting trees in poor soils in Austin, TX
February 27, 2015 - Due to the clay soils and poor drainage in East Austin, what ornamental trees do you normally suggest?
view the full question and answer

Malpighia glabra for Austin
October 14, 2010 - Dear Mr. Smarty Pants, I am planting native Malpighia in a raised bed that was specially prepared for growing roses (soil and amendments). This bed has been left fallow for several years. Do I need t...
view the full question and answer

Soils for spiderwort from Round Rock TX
August 08, 2013 - We have spiderworts growing naturally in our backyard. We put a large circle around them them with limestone rock (as our beds have) to make their own bed as they clumped in one area. What kind of s...
view the full question and answer

Using Horse Manure for the Garden
July 07, 2016 - Can you use horse manure for decomposed matter for your flower beds, etc.?
view the full question and answer

Fireplace ash as soil amendment in Maine
September 28, 2011 - It seems that the custom where we summer in Maine is to dispose of wood ash from the fireplace on the plants around the outside of the house. I think this is not a good idea. What is your opinion? I w...
view the full question and answer

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