Yes, will gaura survive winter is a clear yes in USDA zones 5b through 10. You need good drainage and a small bit of crown cover. Wet soil kills more plants than cold air. Pick a cold hardy cultivar for the harshest zones.
I lost two Whirling Butterflies plants one cold winter to wet clay near my downspout. The same cultivar in a gravelly bed just 15 feet (4.5 m) away came back fine. The cold was the same in both spots. The water was not. That single winter taught me more than any book.
Gaura winter hardiness is real but it has a cost. The taproot sits deep in your soil through the cold months. Frozen soil locks moisture in place around the crown. If your soil is heavy or wet, the root rots from the inside out. Cold air on its own does little harm.
The key concept is simple. Gaura dies from cold wet feet, not from cold air. You can grow gaura at negative 15°F (-26°C) in zone 5b on well drained ground. You cannot grow it at 20°F (-7°C) in zone 8 with soggy clay. Drainage trumps the zone every time.
Sources do not all agree on the zone range, which shows how much cultivar choice matters. Wisconsin Extension lists zones 5b to 9a. NC State lists 5a to 9b. TTU pegs the range at 6 to 10. Pick your cultivar to match your local winter.
Gaura cold tolerance drops as soil moisture goes up through the winter. Your goal is to keep the crown dry from November through March. Skip all fall watering after September 15 in cold zones. Let the natural rain handle the soil moisture from that point on.
I now check my drainage every fall before the first frost arrives. I run my hand into the soil 6 inches (15 cm) down near each plant. If it feels soggy, I add a 2 inch (5 cm) layer of pea gravel around the crown. This small step has saved many plants over the years.
Gaura hardiness zones can be pushed by one full zone with smart gaura winter protection. Pile 2 to 3 inches (5 to 8 cm) of straw or shredded leaves over the crown after the first hard frost. Do not mulch before frost or you trap warm wet air. That can rot the crown.
Lift your potted gaura into an unheated garage if you live below zone 6. Plants in pots freeze faster than those in the ground. Aim to keep the root zone above 20°F (-7°C) all winter. Move pots back outside once nighttime lows stay above freezing in spring.
Skip your fall pruning if you live in a cold zone. Standing stems trap snow that acts as insulation. Cut stems back to 6 inches (15 cm) in early spring once new growth shows at the base. Your gaura will return strong year after year with this small bit of care.
Read the full article: Gaura Plant Growing Guide
