Over Winter Garlic

This year's garlic crop has over wintered well. Most of the cloves planted back in October have grown and I now have healthy looking stems that are 30cm tall. I can't say the same about my over wintered onion crop. For the second year in the row there has been very poor germination from the onion sets. I will buy some new sets in the coming weeks to fill in gaps in this year's onion bed but don't believe I will be over wintering onion sets again for some time.