From Netherland Bulb:

These onions are resistant to bolting and are very long keeping. Sets produce onions that will store all winter.

Dutch onions are much easier to grow than growing onions from seed.
Planting and Maintenance Info:

Light Requirements: Full Sun
Planting Depth: 1 Inches
Bulbs per Square Foot: 3

For best results follow planting instructions on the back of this package.