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?


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
Not Yet Rated

Tuesday - August 12, 2008

From: Washington, DC
Region: Mid-Atlantic
Topic: Watering
Title: Self-watering planters
Answered by: Barbara Medford


I'm a big proponent of the EarthBox (tm) phenomenon - that is, so-called "self-watering" or sub-irrigation planters where a separate but connected reservoir underneath the soil in the planter is filled and the plant draws its moisture upward from there. You don't water the plant, you water the reservoir. My question is this - many websites seem to suggest that a plant cannot be overwatered through this method because the plant "takes what it needs and that's it." It seems more realistic to me that, unless the planter is in full sun for the majority of the day, the plant will not use that much water, the soil will become overly wet, and the roots will rot. Shouldn't an indoor sub-irrigated planter be allowed to dry out somewhat before being replenished? Thanks in advance!


Since we had never even heard of this product, we went to some of the websites on it. We couldn't pass any kind of judgment on something we had never personally used. However, just from the instructions, it seems to be an awfully complicated way to grow a plant. Our impression was that it was mostly being utilized as a means to produce vegetables. The Lady Bird Johnson Wildflower Center is committed to the use of plants native to North America and to the area in which they are being grown. Very few vegetables are native to North America and those that are have been so extensively hybridized that they really don't fall into our area of expertise. It seems a number of the users are from the U.K., where perhaps they don't have enough sunlight or warm weather to grow things in the dirt.

To attempt to answer your question about whether the roots are safe from drowning in the planter, we would imagine they are. Probably the system works just fine; the company would have difficulty continuing to sell them if the plants in them croaked. Really, our own problem with the concept is that it kind of takes the fun out of gardening. To many gardeners, present company included, gardening is something you DO, not something you get produce from. It seems like a lot of trouble and expense to grow things that can be purchased at the grocery store. Pottering around among the plants, deadheading, sprinkling, pulling up the odd weed, and having a chat with the recalcitrant members of your plant family would all be replaced by plastic, fertilizer strips, netting and screens. It is not the policy of Mr. Smarty Plants to weigh in for or against commercial products; decisions on this should be left to the individual.

We did find some websites on the product that you may want to look at; mostly they are from the company itself, but one, Dave's Garden forum on The Scoop on Earth Box, has some comments from people who have used them. One from the company is Welcome to Earth Box.


More Watering Questions

Watering a Chinquapin Oak in Austin, TX
June 22, 2014 - I have a question about watering. I planted a Chinquapin Oak about 7 months ago and it's about 8 feet tall and doing well. I water it weekly on a slow drip for about an hour. I expect that my job is ...
view the full question and answer

Native plants for sandy soil and not much water
April 14, 2008 - I am planning a new garden at home and would like to grow native plants that can handle sandy soil and don't need much water. I do not water my gardens.I would prefer plants that can have more than o...
view the full question and answer

Why are the leaves on my Laurel hedge turning brown in Everett, WA?
February 22, 2010 - Our laurel hedge seems to have brown leaves on the top of the bush. We haven't had a freezing winter so we are trying to figure out why some of the leaves are brown.
view the full question and answer

Hollies not retaining leaves in Tulsa
August 10, 2008 - I have Little Red Hollies that have lost their leaves, some areas being bald. They are also not full - you can see through them. These were planted in this condition Spring of '08 and have been wat...
view the full question and answer

Powdery mildew hits Rock Rose in Round Rock Texas
May 05, 2011 - My beautiful Rock Roses have gotten spots of white fuzzy "fur" on their leaves in the past month. This is not something they have ever had before and I'm worried its some kind of disease. Is it so...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center