What do you fertilize daffodils and hyacinths with?

The best fertilizer for daffodils and hyacinths is a mulch. The earthworms, and other decomposers, will break down the mulch and take it deeper into the soil. The more organic material in the soil the better the nutrient availablity. If you use a chemical fertilizer, you must pay attention to the ratiOS. Too much nitrogen will give you a bunch of green leaves, but reduces the number of flowers.