North America Native Plant

Tharp’s Phlox

Botanical name: Phlox drummondii tharpii

USDA symbol: PHDRT

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Phlox drummondii Hook. var. tharpii (Whitehouse) Erbe (PHDRT2)  âš˜  Phlox glabriflora (Brand) Whitehouse ssp. tharpii (Whitehouse) Wherry (PHGLT2)  âš˜  Phlox tharpii Whitehouse (PHTH3)   

Tharp’s Phlox: A Charming Texas Native Worth Discovering If you’re looking to add authentic Texas flair to your wildflower garden, Tharp’s phlox (Phlox drummondii tharpii) might just be the hidden gem you’ve been searching for. This delightful annual native offers all the charm of its more famous cousin, Drummond’s phlox, ...

Tharp’s Phlox: A Charming Texas Native Worth Discovering

If you’re looking to add authentic Texas flair to your wildflower garden, Tharp’s phlox (Phlox drummondii tharpii) might just be the hidden gem you’ve been searching for. This delightful annual native offers all the charm of its more famous cousin, Drummond’s phlox, with its own unique Texas personality.

What Makes Tharp’s Phlox Special?

Tharp’s phlox is a true Texan through and through. This annual forb is native to the Lone Star State, making it a perfect choice for gardeners who want to support local ecosystems while creating beautiful displays. As an annual, it completes its entire life cycle in one growing season, producing flowers, setting seed, and starting the cycle anew each year.

Being classified as a forb means this plant is herbaceous—it lacks the woody stems of shrubs and trees, instead growing as a soft-stemmed flowering plant that dies back each winter. This makes it an excellent choice for adding seasonal color without the long-term commitment of perennial plantings.

Where Does Tharp’s Phlox Call Home?

This special phlox variety is found exclusively in Texas, where it has adapted to local growing conditions over thousands of years. Its limited native range makes it a unique addition to authentic Texas landscapes and a meaningful choice for gardeners committed to preserving regional plant heritage.

Why Grow Tharp’s Phlox in Your Garden?

There are several compelling reasons to consider adding this native annual to your landscape:

  • Native plant benefits: Supporting local ecosystems and wildlife
  • Low maintenance: Adapted to local conditions means less fussing
  • Authentic regional character: True Texas natives add genuine local flavor
  • Annual flexibility: Easy to change up your garden design each year
  • Potential pollinator support: Like other phlox varieties, likely attractive to butterflies and beneficial insects

Growing Tharp’s Phlox Successfully

While specific growing information for this particular variety is limited, we can draw from what we know about related Texas phlox species. Here’s what will likely help your Tharp’s phlox thrive:

Ideal Growing Conditions

  • Sunlight: Full sun to partial sun
  • Soil: Well-draining soil (most Texas natives prefer good drainage)
  • Water: Moderate water needs, drought-tolerant once established
  • Climate: Adapted to Texas heat and growing conditions

Planting and Care Tips

As an annual, Tharp’s phlox will need to be replanted each year or allowed to self-seed. Spring planting after the last frost typically works best for annual phlox varieties. Since it’s adapted to Texas conditions, it should handle the state’s challenging climate better than non-native alternatives.

A Word About Availability

Here’s the honest truth: Tharp’s phlox can be challenging to find in the nursery trade. This particular variety isn’t as widely cultivated as some of its cousins, so you might need to do some detective work to locate seeds or plants. Try contacting native plant societies, specialty wildflower seed companies, or botanical gardens in Texas for potential sources.

The Bottom Line

Tharp’s phlox represents something special—a piece of authentic Texas botanical heritage that you can grow in your own backyard. While it may require some effort to locate, the reward of growing a true Texas native makes the hunt worthwhile. Plus, you’ll be doing your part to preserve and celebrate the unique plant diversity that makes Texas landscapes so distinctive.

Whether you’re creating a dedicated native plant garden or simply want to add some genuine Texas character to your landscape, Tharp’s phlox offers a meaningful way to connect with your local ecosystem while enjoying the simple pleasure of beautiful wildflowers.

Tharp’s Phlox

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Phlox L. - phlox

Species

Phlox drummondii Hook. - annual phlox

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA