The fertility of the ground makes very little difference to the flowering performance of the bulb in the first season after planting.
A good bulb will always, barring accidents, produce a good flower. But to ensure that it goes on producing good flowers in subsequent years, it must produce good leaves, and to do this, it appreciates a bit of help from the ground. Peat, leaf-mould or compost, worked well in before planting, will encourage good roots, the basis of all good plants, and a sprinkle of bone-meal at planting time and immediately after flowering will provide all w food needed.
The manner in which bulbs multiply means that even under tic best conditions, some, left undisturbed in any clump, will emit flower in any given year. This is because they will not be big enough; and there are two distinct reasons for this. Firstly, the new young bulbs, called daughter bulbs, that form naturally around the older bulbs, known as mother bulbs, take more than one year to reach flowering size; and there are bound to be some daughter bulbs. Secondly, if bulbs are overcrowded, as they surely will be in time if not moved, there will not be enough food to keep them all doing well. Some are bound to suffer.
The difference can be detected, with a keen eye, in the vigor of the clump. If it is healthy and spreading, daughter bulbs are being made, and until they are overcrowding each other, they are best left to their own devices. If the clump is not expanding, and the flowers are progressively smaller every year, as well as fewer in number, it is generally from overcrowding and resultant starvation.
In this case, they are best dug up in July or August, and separated. If they are going back in the same place, once the soil is replenished, the biggest bulbs can be replanted. The smaller ones can be planted in a spot where immediate flowering is not important.
