When the chill comes in Autumn many bulbs planted at this time appreciate the coldness to wake them from dormancy and encourage them to sprout in spring.
Many different variates are available but common ones are :
Always select the largest bulbs as these will produce the largest flowers. Smaller bulbs are generally younger bulbs and produce smaller flowers.
Bulbs should be buried in a hole approximately 2-3 times the hight of the bulb and spaced at least twice the width of itself for an attractive clumped look. Always place the shoot towards the top and the root at the bottom. Be gentle when replacing the soil and avoid treading in, as this may damage the bulbs.