Watering needs for bulbs vary a bit, depending on the bulbs and the climate. It's important to be aware that proper watering is useless without the right kind of soil. Bulbs are very sensitive to rot, and watering them too much or growing them in the wrong soil type can cause the bulbs to die. Thus, it's a good idea to get bulbs started right from the start.
When planting bulbs, which is usually done in the late fall, the bulbs should be placed in loose, well-drained soil. Well drained soil will prevent the bulbs from getting soggy, thus discouraging rot and making it more likely that the bulbs will last until spring. The bulbs should be watered in after planting, and the soil should be kept moist for a few weeks while they root. Once winter starts to set in, people should stop watering bulbs. In part, this is because winter weather will take care of their water needs, but it's also because the bulbs are dormant, and have no real need for water.
Once bulbs start to emerge in the spring, people should hold off on watering bulbs until buds for flowers start to appear. Then, watering should be kept up to keep the soil moist, but not wet, throughout the flowering period. To extend flowering, people can pinch off blooms as they start to fade. Once the bulbs are done flowering, watering should be ceased again to allow the bulbs to go dormant. After dormancy, bulbs can be divided and replanted to start the cycle all over again. Not all bulbs need to be divided each year.
When watering bulbs, it is a good idea to use a system which will avoid splashing the flowers with water, because they can rot quickly. Drip irrigation or similar systems can be used to provide bulbs with water without damaging the flowers or drowning them. People may find that automated systems which respond to moisture levels in the soil can be useful for watering bulbs if they have large gardens, or they can check the soil by hand to see when the bulbs need to be watered.
Even when people follow these recommendations for watering bulbs, they can still experience problems. Sometimes pockets of dense soil trap water, and bulbs in these areas may get waterlogged. Animals underground such as gophers also greatly enjoy bulbs, and may eat them before they have a chance to come up in the spring. One way around this problem is to bury planters underground and place bulbs in them; the planter will be invisible from the surface, but it will keep garden pests out so that the bulbs stay safe.