From the moment the plants are actively growing, the soil should be kept moist, but never soggy. Bulbs do not need feeding before they flower. If your garden has poor soil the bulbs should be fed after blooming, when they are storing food for the following season’s growth. Feed the plants with a liquid or granular balanced fertiliser and continue to water in dry conditions until the leaves begin to die off naturally. This may take about two or three months. After flowers have finished, cut off the spent flower stems but do not cut back the foliage. If you cut off the leaves before they died down naturally, the bulb will not have the reserves to grow and flower the following season.  Some bulbs are not winter hardy, hence in cold climates those bulbs should be lifted and stored to be used the next season. The bulbs can be stored in a paper bag. You should store them in a dark, cool and dry place that is well ventilated. Make sure that the temperature is constant. Periodic inspections should be made and any bulbs showing signs of mildew or rotting removed. Shaking the bulbs in a plastic sack with a little fungicide is a good measure  of prevention. All physically damaged bulbs should be discarded.

Fertilizers

When using fertilizers one of the best options is bone meal, especially for those bulbs left in the ground year round. Bone meal is a slow acting, long-lasting source of the phosphorus that bulbs need to build good root systems. Apply it at a rate of 5 to 6 pounds per 100 square feet, if you plant them in beds, and about a teaspoonful in each hole, if you are naturalizing the bulbs. Scratch the same amount into the soil around the bulbs every fall thereafter.

Another excellent fertilizer for bulbs is dry cow manure and of course compost. The best inorganic fertilizer is a general purpose one such as NPK 5-10-5, with 5% nitrogen, 10% phosphorus and 5% potassium. The higher percentage of phosphorus puts the emphasis on the development of the flower and the root system. Plants need nitrogen for healthy foliage, phosphorus for a strong flower and root system and potassium for firm stems and resistance to disease and cold. Other NPK ratios include 7-14-28 and 12-10-18 both putting more emphasis on firm growth.