Bulbs are notorious for rotting, so it’s really important that you have a well-draining compost that will allow water to run through it easily.
When planting bulbs, use a thin layer of Westland Potting Grit, topped up with Westland Bulb Planting Compost.
This compost is specially formulated for both indoor and outdoor bulbs and contains added grit for free drainage, the correct balance of essential nutrients and trace elements.