Bulbs which fail to produce flowers are often referred to as blind bulbs and there are several reason why this may occur.  Severe attack by various bulb pests and diseases can result in the bulb being unable to produce flowers.  It is also possible for flowering to be halted due to cold weather or an inadequate amount of light.

The major cause for blind bulbs is that the bulbs are not large enough to produce flowers and therefore it is important to look for good sized bulbs at the time of purchase.  For the same reason it is essential then when bulbs have flowered in the garden you do not immediately cut back foliage but allow at least six weeks from flowers fading.  Once bulbs have flowered it is a good idea to apply a general purpose liquid feed, such as Nutri Plant Feed so that the bulbs build up energy for the following year to produce next years blooms.

If you plant undersized bulbs they will flower eventually but it may take a couple of years for them to get up to size.  If a clump of bulbs in your garden that has flowered in previous years does not flower when expected it is a good idea to lift the bulbs when they would normally be planted, divide and replant, congestion may be the cause.

Indoor bulbs should be treated in the same way, they need to be fed and watered so that the bulb builds up reserves and then 6-8 week after flowering slowly dried off, in preparation for the following year.  Flowering may also be inhibited due to dry compost or excessive heat.