Creating areas of special interest through grading the flat Houston landscape

What is grading?
By definition, the grade of the Houston landscape is the elevation or slope of the land. When we say “grading in landscaping,” we are adjusting that elevation by sloping one place to another.

How important is grading in residential landscape design?
It is one of the most important elements of landscape design, although few people who actually enjoy a Houston landscape from a ground-level, experiential perspective.

Water runoff is one of the main functions. Drainage is always a real challenging because over 90% of the Houston landscape is completely flat. Everywhere we build something, we have to contend with getting excess water away from sensitive plants and outdoor architectural structures.

How difficult is changing a grade?
A grade is at once both deceptive and critical to everything, and it works much differently in a yard than it does in the surface area beneath the foundation of a house. For a house, you need a flat plane upon which to build a stable foundation. In a yard, you need a certain level of slope and elevation.

However, saying this is one thing, doing it is another. You cannot simply go behind a home and change the elevation of the entire yard because you will harm or kill trees. Special zones of interest have to be mapped out in the landscape master plan, then graded according to intended use and desired aesthetic form.

What are some examples of what you mean by grading for intended use or desired aesthetic form?
You may have to raise the grade. You want to break up different rooms at different elevations.

How do you do this in landscape that already has been developed to a great extent with pools, outdoor buildings, and pre-existing gardens?
In one Houston landscape project we did, the pool was graded down, and the patio was left high. In effect, we were using the original grade of the pool and enhancing it, rather than forcing a new grade that might have damaged surrounding hardscapes, garden designs, and trees.

This enabled us to not only do some much-needed remodeling on the pool, but it also resulted in a better focal point for gatherings. People seated or standing around the patio could now overlook the pool.

Another project involved creating an area of interest around an outdoor room. What we did here was raise the grade in the rest of back yard, so you had to step down into the back yard to feel an emotional sense of special space. Without this shift, it would not have that feeling of interest.

This was also done in a very subtle way. The grade drop was only about 16 inches. Rather than having 2 8 inch steps, we made 4 four inch steps down the walkway. Four gives you a real sense of lowering elevation, which on a Houston landscape is just enough to create a real sense of emotion and interest.

How do you do this in the front yard?
You may grade the land up and leave the driveway at a lower elevation to partially obscure vehicles that are parked in front of the home.

How do you do this in the back yard?
Pool patios need good drainage without visible slope. We have to pitch the patio all in one direction toward the garden, but we have to mask the slope so people do not feel it when they walk over the patio, nor do they notice it when standing on its surface.