Batten Blooms
PL. —Mirabilis longifloraBotanical illustration — drop image
Mirabilis longiflora

Angel's Trumpets

SpringSummerFall
7a–10bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Peak bloom
Peak bloom
In bloom
Background

Mirabilis longiflora is a tuberous perennial native to the Chihuahuan Desert region of the southwestern United States and northern Mexico. Its common name refers to the exceptionally long, white, trumpet-shaped flowers—often exceeding 5 inches in tube length—that open in the late afternoon and remain open through the night. It handles heat and dry conditions better than most ornamentals and is unrelated to Brugmansia, which shares the same common name.

The plant grows from a fleshy taproot and dies back after frost, re-emerging reliably in zones 7 and warmer. In zone 7, a dry winter mulch over the root zone improves survival. Seeds are large and germinate readily in warm soil when direct sown. Below zone 7, treat as an annual or dig and store the root crown after first frost in slightly damp peat in a cool, frost-free location.

The flowers are shaped specifically for hawk moth pollination: the long tube excludes most insects and concentrates the nectar for sphingid moths. Fragrance intensifies after dark and is strongest in the hours around midnight, making placement near evening seating or a patio the most effective use of this plant.

Good companions
ZinniaCosmosGarden PhloxEnglish Lavender
Care guide
SunFull sun to part shade
WaterLow
SoilWell-drained, dry to moderate
Spacing18–24 in
Height24–48 in
Zone7a – 10b
Native RegionAZ, NM, TX
Direct sow
Seasonal tasks
spring
cutPinch stem tips when plants reach 10–12 inches to encourage branching and more vigorous growth.
sowStart seeds indoors in individual deep pots 6 weeks before last frost; soak seeds in water overnight before sowing to improve germination.
sowTransplant seedlings or direct sow large seeds outdoors once all frost risk has passed and soil temperature is above 60°F.
summer
watchCheck foliage for aphid colonies during warm dry stretches; treat with a strong water spray or insecticidal soap.
watchMonitor for powdery mildew if plants are crowded or airflow is poor; remove affected leaves and improve spacing.
fall
cutAfter first killing frost, cut all top growth to the ground. In zones 7–8, mulch heavily over the root zone to protect the taproot through winter.
watchIn zones below 7, dig the root crown after first frost, let dry for a day, and store in barely damp peat in a cool, frost-free space until spring.
Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Root rot

Symptoms

Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.

Treatment

Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.

Damping Off

Symptoms

Seedlings collapse at the soil line with thin, water-soaked stems; seeds may fail to emerge or rot before sprouting.

Treatment

Sow in well-draining mix, avoid overwatering, and ensure good airflow. Remove affected seedlings and let the surface dry between waterings.