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Thorncrest Agave
Agave lophantha · Asparagaceae (Agavoideae; formerly Agavaceae)
Also called: Quadricolor Agave, Quadricolor Century Plant, Goldteeth Agave
Thorncrest Agave (Agave lophantha) is a low-water accent well suited to Tucson and the low desert. It thrives in full sun to part shade, with a moderate growth rate. Expect greenish-yellow blooms spring to summer.
Thorncrest Agave at a glance
- Water use
- Low (established)
- Sun
- Full sun to part shade; the 'Quadricolor' cultivar shows best color in full to filtered sun but appreciates afternoon shade in the hottest exposures.
- Mature size
- 1.5-2 ft H x 1.5-2 ft W (single rosette; clumps wider over time); flower stalk to 8-12 ft
- Growth rate
- Moderate
- Bloom
- Greenish-yellow, Spring to summer; monocarpic - the individual rosette dies after flowering, but it suckers freely so the clump persists.
- Cold hardiness
- Hardy to about 10-15 F; USDA zones 8-11. Cold-hardy in Tucson.
- Soil
- Well-drained soil; tolerant of rocky, sandy, and native desert soils. Needs good drainage.
- Native range
- Northeastern Mexico into the lower Rio Grande Valley of southern Texas. Not native to the Sonoran Desert/Arizona.
- Best used as
- Accent / focal point (especially the variegated 'Quadricolor'), Container plant, Rock and cactus gardens, Mass plantings and borders, Colorful contrast in desert designs
- Wildlife
- Flowers attract bees, hummingbirds, and other pollinators.
- Toxicity
- Sap is irritating (saponins/oxalates) and can cause contact dermatitis; sharp marginal teeth and terminal spine can puncture. Keep away from walkways and play areas.
How to grow Thorncrest Agave in Tucson & the low desert
Watering
Drought tolerant once established; water every 2-3 weeks in summer for best appearance, less in spring/fall, none in winter. Avoid overwatering.
Fertilizer & nutrients
Generally not needed. A light spring feeding can enhance growth and color on container or young plants; avoid excess nitrogen.
Pruning & care
Remove dead outer leaves and the spent flower stalk; thin out excess pups to manage the clump. Wear heavy gloves and eye protection - the leaves have sharp marginal teeth and a stiff terminal spine.
Notes
Narrow, upright, mid-green leaves with a prominent pale central stripe ('keel') and conspicuous marginal teeth. The widely grown cultivar 'Quadricolor' has four-color variegation - green center, yellow margins, with reddish teeth and red tones in cold/stress - and is the form most often sold under the name. The older name Agave univittata is sometimes applied; A. lophantha is the commonly used accepted name in the trade. Suckers to form colonies.
Sources: AMWUA 'Landscape Plants for the Arizona Desert'; University of Arizona Cooperative Extension; Arizona-Sonora Desert Museum; Tohono Chul / Tucson Botanical Gardens plant references