Ask Mr. Smarty Plants

We will start with your ants, which is not a plant issue and, since we are not entomologists, we can't help you too much. It sounds like you have, since this is Central Texas, Fire Ants. Read this University of California Integrated Pest Management article on Fire Ants. As to the subject of plants "doing well" with ants, ants are farmers and do not eat leaves or buds on plants. What they farm is aphids, or rather the "honeydew" that aphids excrete, and the ants will fiercely defend their crops. The aphids are destructive, eating holes in leaves and laying their eggs on the underside of the leaves. Generally speaking, insecticides not only do not remove the aphid eggs nor their ant caregivers, but can kill the ladybugs which are predators of the aphids. For more information, read this Integrated Pest Management article on aphids.

As for your plant needs, we would first mention that the Lady Bird Johnson Wildflower Center is dedicated to the growth, propagation and protection of plants native not only to North America but also to the areas in which those plants grow normally. Most members of the Rose family are not native to North America, but rather to China. Cuphea hyssopifolia (Mexican heather) is native to Mexico, Guatemala and Honduras, USDA Hardiness Zones 9 to 11. Lantana urticoides (Texas lantana) (see picture below) is native to Travis County, but if you purchased your lantana at a commercial nursery or home improvement store, you are more likely to have Lantana camara (from the Missouri Botanical Garden).

Since we are not quite sure what a "companion"or "complimentary" plant is, we will tell you how we help our guests select plants for their gardens. Most gardeners start at the wrong end, they buy a plant or plants that they like, and then they want to know how to "make" them grow where they are. Our approach is to ascertain where the gardener is, and search our Native Plant Database for appropriate plants to that area. This means that the hardiness zone, the climate, the amount of rainfall and, most especially, the soils will work with the plants chosen. In Austin, we live on the Edwards Plateau. When you go to that page, be sure and read this descriptive paragraph about our area and soils:

"Edwards Plateau

The Edwards Plateau area includes 1.45 million acres known as the Granitic Central Basin in Llano and Mason Counties (Table 2). The Balcones Escarpment forms the distinct boundary of the Edwards Plateau on its eastern and southern borders and outlines what is known as the Texas Hill Country. The area is a deeply dissected, rapidly drained stony plain having broad, flat to undulating divides. The original vegetation was grassland or open savannah-type plains with tree or brushy species found along rocky slopes and stream bottoms."

Most of the Edwards Plateau contains mottled yellowish clay to clay loam surface soil which quickly turns into rocky clay or solid limestone rock layers beneath the surface. Erosion has left most of the region with very shallow soils of less than 10 inches. So, if you want your plants to do well, or even survive, here in Austin, you will be better off choosing plants that can live in that environment. To that end, let us direct you to a list of plants that are native to the Edwards Plateau. This will produce a list of 338 plants that are compatible to this region. Using the list of selections on the right-hand side of that page (you do not need to select a state, the Edwards Plateau is only in Texas) you can choose Habit (tree, shrub, etc), amount of sunlight available, soil moisture,even plant height, duration and bloom time and color. It's fun to play with this because you can make up your ideal plant, and Narrow Your Choice. You may not get a single choice, and will have to modify your requirements. When you click on a plant link, it will take you to our webpage on that plant and you can see pictures of it, learn its growing requirements and, scrolling down to the bottom of the page, click on the link to Google for even more information. These webpages all appear in our Native Plant Database, and you can select from that in the same manner, but the Edwards Plateau list will be more likely to suit your purposes.