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?

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
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
3 ratings

Tuesday - December 04, 2007

From: Phoenix, AZ
Region: Southwest
Topic: General Botany, Watering
Title: Effect of epsom salts and gray water on plants
Answered by: Nan Hampton

QUESTION:

We live in Phoenix where water is a precious commodity. We have decided to use as much of the gray water as we can for watering our garden, shrubs and trees. One of the suggestions we heard about was to use the water from the bathtub. We were wondering if the Epsom Salts(magnesium sulfate-MgSO4.7H2O) that we use in the bath water is harmful to the plants and/or trees?

ANSWER:

Well, unless the concentration of epsom salts in your bath water is very high, it will probably be beneficial to your plants. Both magnesium and sulfur are necessary plant nutrients. Plants need magnesium for the production of chlorophyll and, therefore, it is necessary for photosynthesis. Magnesium is also important in activating many enzymes. Sulfur is a component of some amino acids and is also a component of some enzymes. You can read more about the effect of epsom salts on plants in:

What is the effect of epsom salt on a plant? and How does epsom salt affect plant growth?

Generally, the level of each of these nutrients in soils is high enough for the plants' health. However, sometimes soil has low levels of Mg and/or S and, in that case, epsom salts are recommended as a fertilizer.

You can see recommendations from basic-info-4-organic-fertilizers.com for proportions for the application of epsom salts as a plant supplement. You can compare these proportions with the concentration of epsom salts in your bath water. If your bath water isn't more concentrated, then your plants will probably benefit from its application—not only for the moisture but for the added nutrients as well.

 

More Watering Questions

Yucca rostrata needs some help in Austin, TX.
September 16, 2013 - We planted an expensive 5-6 foot Yucca rostrata last fall. It bloomed beautifully in the spring. We installed an irrigation link to water the recently planted areas with succulents, viburnums, spart...
view the full question and answer

Water eroding corner in Austin
October 25, 2011 - I live close to the Wildflower Center. My yard slopes - as do my neighbors' yards to one corner in my yard. The result is constant moisture in one corner. The rest of the yard is caliche, rocks (m...
view the full question and answer

Texas Pistachio trees dropping leaves in Austin
June 09, 2010 - I have several Texas Pistachio that are about 13 years old. Despite good rainfall in Travis county this year, they seem to be losing most of their new leaf growth now in early June. Leaves are simpl...
view the full question and answer

Recently planted live oak tree in Boerne, TX
February 07, 2009 - My brother planted a live oak in August. It was from a nursery and had a root ball. It looks dead but I keep watering it. The trunk is about 6 inches around. The leaves died but when the winds came th...
view the full question and answer

Drought stressed wooly butterflybush in Atlanta, TX
September 24, 2011 - My butterfly bush is dead looking from the drought. Do you think there is a chance it just went dormant and will return next year. I am still putting water on it. I believe it is a white wooly butterf...
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center