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?

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

Lupines annual or perennial in Zone 4b from Austin
November 08, 2012 - Are lupines treated as perennials or annuals in Zone 4b (Northeast) if they are planted in the ground? Will other native species of lupines grow in a region they are not native to? Any recommendations...
view the full question and answer

Expanded Shale Availability in Austin Area
March 18, 2016 - Where can you find expanded shale in bulk or bag in the Austin area?
view the full question and answer

Garden instructions from Austin
June 12, 2013 - I'm a beginning gardener putting in some new landscaping in my front yard in north central Austin, TX. The yard faces almost due east, so it gets full sun until early afternoon, when the house's sha...
view the full question and answer

Disagreement with HOA on raised beds placed beneath mature oak from Tequesta FL
April 05, 2014 - I have mature 30 year old oak trees on my property and I put a raised bed under each with very good soil and I used pavers for retaining the soil about about 1.5 ft high. I planted a perennial begonia...
view the full question and answer

Potting soil mixture at Wildflower Center from Austin
August 14, 2012 - What potting soil mixture does the Wildflower Center use in its greenhouses for the native plants grown for the Austin Native Plant sales? Is the pH adjusted to match the alkaline soils in this area? ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center