Agave ovatifolia aka Whales Tongue Agave

Agave ovatifolia is an evergreen succulent from Nuevo León, Mexico. It belongs to the asparagus family, Asparagaceae. Its common names include whale's tongue agave and oval-leaved agave. It grows in dry shrubland and on mountain sites. Wild plants occur at 3,940–6,890 feet [1,200–2,100 metres]. The plant forms a broad, rounded rosette with a flattened top. Most plants grow alone rather than forming clumps.

Garden plants reach about 3–5 feet [1–1.5 metres] tall. Their spread can reach 5–8 feet [1.5–2.5 metres]. LLIFLE reports plants reaching 6.6 feet [2 metres] tall with ample water. Broad, egg-shaped leaves give the plant its name. Their pale blue-green surface can look almost white. Each leaf has a deep groove along its upper face. Small, hooked teeth line the edges of each leaf. A sharp, dark spine ends each leaf. Plants seldom form offsets, though LLIFLE records rare exceptions.

Yellow-green flowers appear in summer, with records spanning June through August. The plant flowers once after many years, then dies. Sources differ on the height of the flower stalk. RHS gives 5–6.6 feet [1.5–2 metres]. LLIFLE gives 10–15 feet [3–4.5 metres]. Side branches carry dense groups of flowers on the stalk. Missouri Botanical Garden lists birds, hummingbirds, and butterflies among its visitors. RHS gives a maturity period of ten to twenty years.

Grow it in full sun and soil that drains freely. LLIFLE also reports good growth in light, filtered shade. It accepts chalk, loam, or sand across a broad pH range. Established outdoor plants cope with drought and dry, rocky soil. Extra water can increase growth and final size. Let the soil dry well between waterings. Keep container plants safe from excess winter wet. RHS rates it H3; Missouri Botanical Garden lists USDA zones 7–11. LLIFLE reports survival near 10°F [−12°C], with dry conditions improving cold tolerance. Long cold spells near 18°F [−8°C] may damage leaves.

Its bold shape suits rock gardens, gravel beds, and dry gardens. It also serves as a focal plant in patio pots. Care needs are low, and it needs no pruning. Sow seed in early spring to raise new plants. Scale insects may attack, but sources report few serious health problems. Handle it with gloves and other protective clothing. The plant can irritate skin, and its spines are sharp. Dogs and cats may suffer harm if they eat it.