The some of the information below is from the Houston Chronicle, June 2, 2009 “Houston’s favorite summer blooming perennials”. These are just a few of the many perennials that are easy to grow in the Orange County, Texas area.
1.Butterfly weed, perennial, flower, Asclepias tuberosa
Butterfly Weed
Height: 3 feet
Flower color: Orange, red, yellow, multicolor
Light requirements: Full sun to part sun
Soil: Light with good drainage
Bloom season: March to October
Ideal planting time: Spring or fall
Cold tolerance: Root hardy and will regrow in spring
Hard to kill: Yes
Special attributes: Attracts butterflies, Texas native
2.Texas sage, perennial, flower, Salvia coccinea
Texas Sage
Height: 2-4 feet
Flower color: Pink, red, white
Light requirements: Sun to bright shade
Soil: Organic with good drainage
Bloom season: April to frost
Ideal planting time: Fall
Cold tolerance: Root hardy and will regrow in spring
Hard to kill: Yes
Special attributes: Attracts hummingbirds, texas native
Uses: Mixed border, shade garden, Deer resistant
3.Summer phlox, perennial, flower, Phlox paniculata 
Height: 2-4 feet
Flower color: Pink, magenta, white, multicolor
Light requirements: Full sun to part sun
Soil: Organic with good drainage
Bloom season: May to October
Ideal planting time: Fall or early spring
Cold tolerance: Root hardy and will regrow in spring
Special attributes: Attracts butterflies
Uses: Mass plantings, mixed border
4.Agastache, anise hyssop, perennial, flower, Agastache foeniculum
Anise Hyssop
Height: 2 to3 feet
Width: 2 feet
Flower color: Lilac
Light requirements: Sun
Soil: Organic with good drainage
Bloom season: Summer
Ideal planting time: Fall
Cold tolerance: Root hardy and will regrow in spring if top damaged
Special attributes: Attracts butterflies, attracts hummingbirds
Uses: Mixed border
5.Mexican oregano, perennial, flower, Poliomintha bustamenta
Mexican Oregano
Height: 3-4 feet
Light requirements: Full sun to part sun
Soil: Can grow in most soils with good drainage
Bloom season: May to September
Ideal planting time: Fall
Cold tolerance: Root hardy and will regrow in spring
Hard to kill: Yes
Special attributes: Attracts butterflies, disease resistant
Uses: Container, mixed border
Australian Violet
6.Australian violet, perennial, groundcover, Viola hederacea
Height: 4-6 inches
Growth rate: Fast
Flower color: Purple, white
Light requirements: Part sun to bright shade
Soil: Organic, moist
Bloom season: Spring to frost
Ideal planting time: Spring to fall
Cold tolerance: Root hardy and will regrow in spring if winter damaged
Special attributes: Disease resistant
7.Rangoon creeper, perennial, vine, Quisqualis indica
Rangoon Creeper Vine
Height: To 30 feet
Flower color: Pink, red, cream
Light requirements: Sun
Soil: Organic
Bloom season: Summer to fall
Ideal planting time: Fall to spring
Cold tolerance: Root hardy and will regrow in spring
Hard to kill: Yes
8. Purple heart, wandering jew, perennial, groundcover, Tradescantia pallida ‘Purple Heart’
Purple Heart Wandering Jew
Height: 12 to 18 inches
Width: 12 to 18 inches
Growth rate: Fast
Flower color: Lavender, purple
Light requirements: Sun to bright shade
Soil: Tolerates most well-draining soils
Bloom season: Spring to fall
Ideal planting time: Spring
Cold tolerance: Root hardy and will regrow in spring if top damaged in winter
Hard to kill: Yes
Special attributes: Disease resistant, drought tolerant
9.Bouncing bet, perennial, flower, Saponaria officinalis
Bouncing Bet
Height: 1-2 feet
Flower color: Pink
Light requirements: Full sun to part sun
Soil: Can grow in most soils with good drainage
Bloom season: May to August
Ideal planting time: Fall or early spring
Cold tolerance: Root hardy and will regrow in spring
Hard to kill: Yes
Special attributes: Drought tolerant
Uses: Groundcover
10.Butterfly vine, perennial, vine,
Butterfly Vine ‘Mascagnia macroptera’
Height: 12 to 18 feet
Flower color: Yellow
Light requirements: Early sun or part sun
Soil: Organic with good drainage
Bloom season: May to frost
Ideal planting time: Spring or fall
Cold tolerance: Root hardy and will regrow in spring