Puya alpestris — Sapphire Tower — is a terrestrial bromeliad native to the dry, rocky slopes of the Chilean Andes, where it forms a dense rosette of stiff, silvery-green leaves lined with hooked, recurved spines strong enough to snag wool and skin alike. After roughly seven to ten years of vegetative growth, a rosette sends up a towering flower spike studded with metallic turquoise flowers and bright orange anthers — one of the most striking flower colors in cultivation — and that rosette then dies back, though the surrounding clump carries on.
It needs the same fast, gritty drainage most cacti demand: sandy or gravelly soil, full sun, and water only once the soil has dried out completely. Established plants tolerate brief dips to around 20°F but resent wet, cold winters more than cold air itself, so in zones below 9a it belongs in a large container that can move under cover for the coldest months. Handle it with heavy gloves — the recurved spines are sharp enough to draw blood and can lock onto clothing.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.