Ask Mr. Smarty Plants

We are unfamiliar with that type of septic system, and did a little research on it-learn something every day. At first, we thought you had an aerobic exercise area in your yard. Since we did not know anything about this, an article from damnseptictank.com Aerobic Septic System  helped us to understand what you are dealing with.

This article from InspectAPedia.com Guide to Planting Trees or Shrubs Over or Near Septic System Components has a lot of information on planting trees and shrubs over septic fields (don't) or distances from those fields to plant trees (you don't have that much space).

Beyond that information, about all we can tell you is what we have told others who wanted to know what they could plant over septic systems and let you go from there. These are all Mr. Smarty Plants answers to previous questions and some have more links for information. These involve different areas of the country and different plants but all are applicable to your question. Unfortunately, a couple of these reference the Ford County, Kansas Septic System Information website, which is no longer active. Darn shame, because it was a very good source of information.

June 28, 2010 Planting over septic tank in California

September 2, 2009 Native flowers from Door County WI

March 10, 2009 Replacement for black walnut near septic tank

February 4, 2009 Native plants for septic system in Massachusetts

January 25, 2009 Plants that will not clog lateral lines with roots from Bulverde, TX

April 10, 2008 Native plants for septic field from Austin, TX

From the above answers, we hope you have inhaled the information that, especially in a small space, woody plants are not a good idea. In terms of the tropical plants you are asking about that won't freeze and are heat tolerant, most tropicals are non-native to North America. The Lady Bird Johnson Wildflower Center is all about the growth, protection and propagation of plants native not only to North America but to the area in which those plants are being grown. Plants native to your area in South Texas should already be acclimated to the sort of temperatures you normally have. Even in Houston, there have been bad freezes and there will be again, but a native plant that has millennia of experience in infrequent bad freezes has a better chance of surviving.

From our Recommended Species section, here are a couple of plant lists that might apply in your situation:

Gulf Prairies and Marshes

Great Small Trees for Houston

From that same Recommended Species section, you can click on either South Texas or East Texas on the map, and then search for specific plants for your area by General Appearance or Habit, such as herbaceous blooming plants, grasses, vines, etc. Following each plant link on each of these lists will take you to our webpage on that plant and help you learn how large it may get, what light requirements it has, when it blooms, etc.