Fertilizing Spring Blooming Summer Dormant Bulbs
Judy Glattstein (Fri, 15 Apr 2016 06:42:53 PDT)

My favorite technique is to use a liquid fertilizer at half strength in
three applications - if I am organized (rare occurrence) that would be
pre-bloom but well leafed out, post bloom, and three to four weeks after
the flowers fade but before leaves yellow.

I like Jack's Classic Blossom Booster, which has a 10-30-20 analysis.

It is absorbed through the leaves as well as taken up by roots so I mix
and just slosh over the plants using a watering can. Very good when
lifting, dividing, and replanting bulbs still in leaf.

Judy in New Jersey on a nice sunny day