Onc. sphacelatum

This orchid had 53 flower racemes, each about 1 metre (3 feet) in length with hundreds of individual flowers on each raceme. This orchid created a spectacular display. It was originally planted in a plastic bread tray, but this has long since disappeared beneath the mass of leaves and pseudobulbs. This orchid is now so large that Leo has given up any idea of repotting. Leo grows this orchid in his garden where it gets virtually full sun, watering when it rains or Leo waters the garden and fertilising when ever there is some orchid fertiliser left after fertilising the orchid houses, generally very infrequently.

Onc. sphacelatum is a native of Mexico to Costa Rica and Venezuela. It grows easily in our climate, and will grow to huge specimens such as Leos if allowed. It will tolerate full sun, although it prefers some protection in summer. About 30% shade in summer and full winter sun is ideal, however, sphacelatum will tolerate very low light levels and still flower. Watering is not critical with Onc. sphacelatum as it has large pseudobulbs to contain large reserves of food and water. It does however prefer regular watering during summer.

Fertilising is also not critical with Onc. sphacelatum. Again, regular fertilising will help its growth, but it will tolerate long periods without any fertiliser. As for potting medium, Onc. sphacelatum prefers to ramble out of whatever it is potted in. Growers generally try to pot Onc. sphacelatum in a course bark mix, but this orchid generally outgrows its container quickly and happily rambles over the edge and will grow on whatever it can find. Onc. sphacelatum will also grow happily mounted, but most growers do not grow this orchid this way as it outgrows its mount too quickly.

Onc. sphacelatum does not really suffer from pest problems. Grasshoppers can chew the leaves occasionally, but this is generally not too bad. Grasshoppers do however enjoy the flowers, so you need to watch for them when in flower. Otherwise, Onc. sphacelatum does not really suffer from any pest problems.