My sister lives in Houston and wants to plant some screening shrubs or something to add a little privacy to the perimeter of her backyard. I know a lot of the normal choices around here (arborvitae, viburnum, holly, Rose of Sharon, etc...), but I'm not familiar with what can tolerate the extreme heat they get down there. To add to it, the area she wants to plant is in full sun. I started to do some Googling, but thought I would ask the pros here. She doesn't care if it is evergreen or deciduous. I don't think she is looking for a shaped hedge - probably something more low maintenance. She would prefer to stay away from real pricey species. Any suggestions?

Usually, the easiest place to start is to head for the local nursery. They tend to have species that will tolerate the climate for any location, and the folks in a privately owned, smaller nursery are more knowledgeable.

If Houston's having the same weather as the rest of Texas, drought-tolerant would probably be a big plus. Maybe large cacti?

I mentioned just going to a nursery for her, but she has no idea what she is looking for or who to trust. She doesn't have much of a green thumb (trying to pay me to come down and plant them!), but she isn't opposed to watering or setting up additional drip zones for them.

Excellent resource. Sending her that and to look for Zone 9A.

Has she considered ornamental and native grasses. I have started growing them. There is another web site that has an ornamental grass forum and a lot of folks in TX and OK participate on it. They grow a lot of native grasses that survive in their drought and heat.

Ditto here, but same as BPGreen. My Zebra and maiden grasses wouldn't be happy in TX, I don't think.

Miscanthus would not be a good choice there because it does like water. Have a look at Panicum Switchgrasses ('Dallas Blues', etc.), Little Bluestem ('the blues'), Prairie Dropseed, Mexican Feather grass, Muhlenbergia (Lindheimer's Muhly, etc.). There are many more than this that would grow well in TX.

Around here from the coast to the Inland Empire (HOT), these two are very popular plants. Once established, they are both drought tolerant. I have a privet which I do not take care of much so it is thick but not very tall. It flowers in the spring. My neighbor has oleander which he does not water much and they are approx 15ft tall and doing well. They flower late spring, summer and fall.

Oleander

Privet

I love oleander but remember that all parts of the plant are toxic...very, very toxic. White oleander is not my idea of a fun way to go.