When I first plant I use 6-12-12. After the tops start growing I go with all nitrogen. I've got some 46-0-0 i used this year. But I go light with that stuff. But spread a little every 2-3 weeks until the bulbs stop swelling. The info on DixonDales site explains the fertilize part really well. This is the first year I have fertilized and watered like they are suppose to be. Seeing good results so far.