Groundcover
Garden verbena
Glandularia x hybrida · Verbenaceae
Also called: Verbena, Hybrid verbena, Annual verbena
Garden verbena (Glandularia x hybrida) is a low-water groundcover well suited to Tucson and the low desert.
Garden verbena at a glance
- Water use
- Low (established)
- Sun
- Full sun for best, most compact bloom; will take light afternoon shade in extreme Tucson heat. Insufficient sun produces sparse flowering and leggy, mildew-prone growth.
- Mature size
- Low spreading mat about 6-12 in. tall and 18-36 in. wide.
- Growth rate
- Fast.
- Bloom
- Wide range - purple, red, pink, white, lavender, magenta, coral, and bicolors, in flat-topped clusters., Long season in Tucson - heaviest in spring (peaks roughly Feb/Mar-June) and again in fall; may slow during the most intense midsummer heat and flush again with cooler weather and monsoon.
- Cold hardiness
- Frost-tender to root-hardy depending on cultivar; tops may be nipped below ~28-32°F. In Tucson (USDA 9a-9b) often grown as a short-lived perennial or cool-season-into-spring annual, returning after mild winters.
- Soil
- Light, well-drained soil is essential; tolerates lean, alkaline desert soils but rots in heavy, poorly drained spots. Amend caliche/clay with compost and grit.
- Native range
- Garden hybrid of South American Glandularia (formerly Verbena) species; not native. Note: several native verbenas (e.g., Goodding's verbena, Glandularia gooddingii) are Sonoran/Southwest natives, but this hybrid group is not.
- Best used as
- Groundcover and edging, Containers, hanging baskets, and window boxes, Front-of-border color, Rock and gravel gardens, Pollinator and butterfly gardens, Spilling over walls and slopes
- Wildlife
- Excellent butterfly nectar plant; also draws bees and other pollinators.
- Toxicity
- Considered low toxicity / generally non-toxic to humans and pets; a safe choice around children and animals.
How to grow Garden verbena in Tucson & the low desert
Watering
Drought tolerant once established but flowers best with regular moisture. In Tucson, water about 2x per week in summer heat and weekly in spring/fall; allow soil to dry slightly between waterings and ensure good drainage to avoid root rot and mildew. Reduce in winter.
Fertilizer & nutrients
Light feeder. Feed with a balanced or bloom-type fertilizer every 4-6 weeks during the active growing/blooming season for continuous color; avoid excess nitrogen, which favors foliage over flowers.
Pruning & care
Shear back by about one-third after each major flush of bloom to deadhead, refresh, and prevent legginess and reblooming; this keeps it dense and floriferous. Cut back hard in late winter to renew.
Notes
Formerly classified as Verbena x hybrida; now placed in Glandularia. A reliable low, spreading color plant for Tucson, best in cooler months and spring/fall when it blooms most heavily. Tends to be short-lived (1-3 years) and can decline in peak summer heat and humidity - good drainage, air circulation, and shearing after bloom prolong its life and prevent powdery mildew and spider mites.
Sources: Arizona-Sonora Desert Museum plant care sheet - Glandularia (desertmuseum.org/visit/sheets/Glagoo.pdf); AMWUA / Water Use It Wisely - Glandularia formerly Verbena (wateruseitwisely.com); Texas Tech Plant Resources - Glandularia x hybrida (depts.ttu.edu); University of Arizona / Pima County Cooperative Extension