Ask Mr. Smarty Plants

There is no doubt that snakes will be seeking shade in this torrid summer.  There will always be the shade cast by your house itself.  You might try to make certain that there are alternative sources of shade available at some reasonable distance from the house, such as a grove of trees or shrubs.  Hopefully, rattlesnakes will will find this more attractive than your shade. 

In your own garden the best protection from snakes is to have few hiding places for them.  Make sure that rocks, logs, rotten stumps, lumber piles, and other places of cover are cleaned up. Keep the native grasses that you are planting mowed fairly close to the ground. Fill any cracks in the house foundation that could permit snakes to enter.  Since snakes often come to an area in search of prey, eliminating rodent populations, especially ground squirrels, meadow voles, deer mice, rats, and house mice, is an important step in making the habitat less attractive for snakes. Rattlesnakes cannot dig burrows but frequently use those dug by rodents. After controlling the rodents, fill in all burrows with soil or sod and pack down firmly.

Most experts claim that plants do not themselves attract or deter snakes.  But they may attract rodents or other favored snake prey.  So you should consider whether any of your plants might be in that category, e.g., if they produce edible fruit or nuts that fall to the ground.  Mr. Smarty Plants suggests that you choose foundation plants that have relatively small leaves and few leaves near the base.  This will minimize the shade they cast and remove cover, which snakes seek as much as shade.  Some small trees that should do well in Mason and cast light shade include Cercis canadensis var. texensis (Texas redbud),Chilopsis linearis (Desert willow), Callicarpa americana (American beautyberry), Parkinsonia aculeata (Retama), Rhus lanceolata (Prairie flameleaf sumac) and Styphnolobium affine (Eve�s necklace). Shrubs having a base largely free of leaves are Morella cerifera (Wax myrtle), Eysenhardtia texana (Texas kidneywood), Ilex vomitoria (Yaupon) and Rhus virens (Evergreen sumac).  Wax myrtle, yaupon, and evergreen sumac are fully evergreen. 

Rattlesnakes are not climbers, so you should consider vines.  Campsis radicans (Trumpet creeper), Clematis texensis (Scarlet clematis), Lonicera sempervirens (Coral honeysuckle), Passiflora incarnata (Purple passionflower) and Bignonia capreolata (Crossvine) should thrive in your location.  Only Crossvine is evergreen.  Smaller plants largely open at their base include Asclepias tuberosa (Butterflyweed), Chrysactinia mexicana (Damianita), Helianthus maximiliani (Maximilian sunflower), Ipomopsis rubra (Standing cypress), Liatris mucronata (Cusp blazing star), Lobelia cardinalis (Cardinal flower), Penstemon triflorus (Hill country penstemon), Ratibida columnifera (Mexican hat) and Salvia farinacea (Mealy blue sage).  Careful placement and a minimum of ongoing care should give you a relatively cover-free, sunny border not preferred by snakes.

Images of some of my recommendations are shown below.