One way to conserve water is to use plants that don’t need a drink that often.

For our sister publication, Greenhouse Management, staff compiled trial garden results, and trial garden managers from across the U.S. submitted what performed best in their region in a number of categories. We’ve only listed here the best drought-tolerant perennial, best heat-tolerant annual, and best heat-tolerant perennial. For all the results, visit The 2021 results will be available later this year.

Best Heat-Tolerant Annuals

Midwest: Bracteantha Granvia Gold (Suntory Flowers), Plantpeddler

The best bracteantha in the market. Large, long-lasting flowers on top of lush, dark-green foliage. There is also a new Pink in the series.

Midwest: Lantana Bandana Gold (Syngenta Flowers), Raker-Roberta’s Trial Gardens

All the lantanas did well this summer. The Bandana series always performs and this one was full and robust all summer long.

Southeast: Helianthus SunBelievable Golden Girl (Danziger), Young’s Plant Farm

This helianthus just got bigger and better during the summer heat. Features a shrub-like growth habit that is absolutely full of bright, yellow sunflowers. Golden Girl was a showstopper in our summer garden.

Best Heat-Tolerant Perennials

Southeast: Penstemon ‘Dakota Verde’ (Terra Nova Nurseries), North Carolina State University

Glossy, green leaves provide long-term interest. Flowers are a lavender/pink color; the showy dark seed heads that form after bloom are attractive. Can use both the flower and seed heads for cuts. Pollinators like these plants, which is a bonus!

Midwest: Echinacea Sombrero Rosada (Darwin Perennials), Raker-Roberta’s Trial Gardens

The Sombreros always look good. This one’s Pinkish Rose color stood out in our trial.

Midwest: Kniphofia PYROMANIA ‘Backdraft’, (Proven Winners), Walter’s Gardens

The six colors of Kniphofia in the PYROMANIA Collection are tropical-looking perennials but are hardy to zone 5b. ‘Backdraft’ has wide flower spikes that start out an intense reddish orange and open to a peachy yellow for a two-tone color effect. All members of the collection have excellent re-bloom until late into the season and grass-like, textural foliage.

Best Drought-Tolerant Perennials

Southeast: Veronica ‘Venture Blue’ (Terra Nova Nurseries), North Carolina State University

Compact, low-growing plants that are covered in dark blue flowers. Continuous flowering spikes on sturdy upright stems. Low maintenance, easy to grow and no deadheading needed. Handles the heat well.

Midwest: Digitalis Camelot Lavender (Syngenta Flowers), Raker-Roberta’s Trial Gardens

First year planting. Still flowering into October. Series typically performs well.

Midwest: Perovskia ‘Sage Advice’ (Proven Winners), Walter’s Gardens

This perennial is perfect for hot, dry climates, but performs well in a wide variety of environments. ‘Sage Advice’ has rich, lavender purple flowers that are a darker shade than other Perovskia to date. Compared to ‘Denim ‘n Lace,’ this variety has darker flowers and calyces, broad (vs. dissected) foliage, and is slightly taller.

Best Drought-Tolerant Annuals

Southeast: Celosia ‘Bikaver Red’ (HEM Genetics), Young’s Plant Farm

Celosia is a great drought-tolerant plant. ‘Bikaver Red’ is an easy to grow celosia that just gets better as the summer goes on. Bright red flowers on a deep red foliage plant — really stands out in the garden

Southeast: Gaillardia ‘Heat It Up Yellow’ (Proven Winners), North Carolina State University

Compact, uniform mounds covered in clear, bright yellow flowers. Continuous bloomer with no deadheading necessary. Great low maintenance plant. Pollinators like it, too!

Midwest: Lantana Havana Sunset (Dümmen Orange), Plantpeddler

Was very impressed with the growth habit of this lantana along with the flower power during the hot, dry July we had. Came in color early, stayed in color all season, and never lost its color. The pink and yellow blossoms stood out among the rest of the lantana in the beds.