Ask Mr. Smarty Plants

We are assuming you are writing to us from England. When we searched the Internet on "Surbiton,"  about the best clue we got was that it was a suburb of London. So, the first thing we have to tell you is that the Lady Bird Johnson Wildflower Center is devoted to the growth, propagation and protection of plants native not only to North America but to the areas in which those plants grow natively. So there is no way we can recommend plants to you, because all we have in our database are native to North America.

However, we can give you some general help with your soggy area. We have been asked before if there were plants that would soak up water or prevent water from getting into an area. The answer is, plants all need water, but they can only take up so much, and they certainly won't block water. However, long fibrous roots on some plants will help the soil slow down that water, and help to filter out pollutants before it goes rushing off to be in the water supply. You will need plants that can withstand having wet feet during wet and rainy periods, but also that will continue to do all right when it is not so wet.

There is a technique called "Rain Gardens," and we are going to send you some previous Mr. Smarty Plants answers and some references to information on planning a rain garden.

First, here is a portion from an answer concerning a similar situation in Washington, DC which also has some good links to other sites on the same subject.

"The situation you are describing is very similar to a rain garden or bioswale which is a created area much like you already have.  It is used to facilitate the infiltration of stormwater runoff, decreasing erosion and pollution.

You will find some very useful information about rain gardens here on the Landscape for Life website.  There are links to other sites with more information and plant suggestions.  Although none of them are specifically for the DC area, there are many native plants with broad ranges, so there will be plenty of choices for you.  You will find the plant lists posted on the Brooklyn Botanic Garden website particularly helpful."

Then, a portion of another Mr. Smarty Plants answer that has a number of valuable links to solving your problem. Remember, these are all websites originating in the United States, and many reference only plants native to North America, but we think you can take some of the suggestions and apply them to your problem.

"We have a How-To-Article Water Gardening that will give you some ideas on how to treat this area, but that is not exactly what you want. What you want is a wetland or a rain garden, with plants that can both withstand dry weather as well as having their feet in standing water for a short period. 

The best reference source we found was from the Wisconsin Department of Natural Resources Rain Gardens, a How-To Manual for Homeowners. It is fairly lengthy, and probably involves more than you actually need or want to do for your problem area, but it has good explanations of why a rain garden is important to water and soil conservation and quality of our water supply, while giving you an attractive, useful area in your yard.

And, finally, this website Native Rain Gardens makes our point about native plants."