Vine
Yellow Morning Glory
Merremia aurea · Convolvulaceae (morning glory family)
Also called: Yuca Vine, Yuca, Golden Morning Glory, Distimake aureus
Yellow Morning Glory (Merremia aurea) is a very low-water vine well suited to Tucson and the low desert. It thrives in full sun, with a fast growth rate.
Yellow Morning Glory at a glance
- Water use
- Very Low (established)
- Sun
- Full sun (tolerates part shade); flowers best in full sun.
- Mature size
- 15-20 ft H x 10-15 ft W (twining vine from a large tuberous root; can add 20 ft of growth in a season)
- Growth rate
- Fast
- Bloom
- Brilliant clear yellow, 2-inch funnel-shaped (morning-glory) flowers, Summer through fall (warm season, often spurred by monsoon)
- Cold hardiness
- Top frost-tender; the tuberous root is hardy into the low 20s°F (USDA zone 9-11). Freezes to the ground in a Tucson winter and resprouts vigorously in spring.
- Soil
- Well-drained desert soils; very tolerant of sandy, rocky, and alkaline ground. The tuber needs deep, well-drained soil.
- Native range
- Baja California and adjacent Sonora, Mexico (Sonoran Desert region of Mexico, not Arizona)
- Best used as
- Fast warm-season screen for trellises, arbors, and fences, Xeriscape and low-water color, Summer shade cover
- Wildlife
- Bright flowers attract bees and other pollinators.
- Toxicity
- As with many morning-glory relatives, seeds and plant parts are best considered mildly toxic if ingested; not intended for consumption. Keep seeds away from children and pets.
How to grow Yellow Morning Glory in Tucson & the low desert
Watering
Extremely drought-tolerant once established; deep, infrequent watering (every 1-2 weeks in peak summer) keeps it lush and blooming. Overwatering can rot the tuber.
Fertilizer & nutrients
Minimal needs; thrives without supplemental fertilizer in native soil. A light spring feeding can boost growth but is not required.
Pruning & care
Cut frost-killed top growth to the ground in late winter; it regrows readily. Thin and direct the rampant twining stems on a sturdy trellis or arbor during the growing season.
Notes
A Baja California endemic well adapted to Tucson's low desert; reliably perennial from its tuberous root despite winter freezes. Now reclassified by some authorities as Distimake aureus. Grows extremely fast and provides quick warm-season cover.
Sources: Arizona-Sonora Desert Museum plant care sheet (Yellow Morning Glory Vine / Yuca); Desert-Tropicals (Merremia aurea); University of Arizona / regional Master Gardener references; Wikipedia (Distimake aureus) for accepted taxonomy