By Johnhoward
United Kingdom 
I planted garlic and onion sets in November last year for the first time. As the stems have started to wilt they have just been pulled up and are currently laying on the earth waiting for the skins to harden.
The onions were ok (for a beginner), most bulbs about 2 to 3 inches in diameter.
The garlic is another story, of about 25 plants, only a handful have grown to a usable size, most are about 1/2" wide and have just not developed. About 25% of the bulbs have a white powdery coating that I think is mould, some of these bulbs collapse when squeezed.
Where did I go wrong?
What should do better this year?
Are the remaining onions and garlic safe to eat?
What can I plant/should avoid planting in this bed now? I have lots of beetroot and sweetcorn that need a final position, are these ok to plant here?
Many thanks from a rookie!
12 Jun, 2014
Answers
This sounds like onion white rot have a look at the rhs site. I would not grow any leeks, garlic or onions on that patch for a while.
http://www.rhs.org.uk/advice/profile?PID=226
13 Jun, 2014
I can't answer your questions but I can sympathise with you. For the last 3 years I too have set onion sets and garlic, but whlle the onions have been good the garlic has always been disappointing and I've given up on it this year.
I suggest you try shallot sets - they have always done well for me and if you set, say 20, you'll get many more back. Plenty to eat and enough to set the following year.
12 Jun, 2014