How deep to plant peacock orchids

[Bert]

I bought some peacock orchid 'bulbs' (pseudobulb may be the correct term). The very brief instructions with them said they should be planted 15 cm deep. Years ago I heard on a TV gardening programme that bulbs should be planted about three times their height below the surface. (I never knew whether that meant to the top of the bulb or to the bottom of the bulb.) Anyway, these orchid things are quite small, less than 2 cm high, so 15 cm seems more like burying them than planting them. Any advice?

[Hawkwalk]

10cm deep and 15cm apart. A couple of cm either side will not make much difference.