Low water once established. Water deeply, then allow soil to dry thoroughly; provide occasional supplemental irrigation during prolonged Phoenix heat. Water sparingly in winter.
Assuming ‘Agave desipens’ refers to Agave decipiens (false sisal), a large, trunk-forming agave native to Florida with long green leaves, toothed margins, and sharp terminal spines.
Light: Full sun to partial shade; in Phoenix, afternoon shade helps prevent scorching, especially on young or newly planted specimens.
Water: Low water once established. Water deeply, then allow soil to dry thoroughly; provide occasional supplemental irrigation during prolonged Phoenix heat. Water sparingly in winter.
Soil: Very well-drained sandy or gravelly soil. Use a raised mound where native soil is compacted or drainage is poor.
Mature size: Approximately 6–10 feet tall and 6–8 feet wide; old, trunk-forming specimens can grow taller. Flower stalk extends well above the foliage.
Bloom: Each rosette flowers once after many years, then dies; offsets and plantlets can continue the colony. Flowering age varies with growing conditions.
Evergreen / deciduous: Evergreen.
Growth rate: Slow to moderate; faster with warmth and occasional deep watering.