[salmonking]

hi all,last year lots of my onions went to seed,probably half.i was told I watered them too much.so this year I haven't watered them too much but noticed yesterday a seed head on 2 of them.is there anything I can do to stop the rest going?? also if I snap off the seed head/stalk will this stop it?any advice as if this carries on I wont be growing them again!thanks 

[seaside]

Some sets go to seed, some don't. Red ones, especially sturon, do it far more readily, almost 50% in some years. Most people I know don't bother with the red sets.
One should expect maybe 5% to go to seed... all plants have losses. Those onions that refuse to grow up and bulb properly at the end of the Summer are far more of a loss.

[BabbyAnn]

Onions tend to flower in the 2nd year, so when planting sets, they are still in the 1st year.  If the sets are planted too early, there is an increased risk of the weather turning cold - sharp frost, late snow.  This interrupts the growing cycle and prompts the plant to shift into the 2nd year growth which is to go to seed.  For some reason, red skinned onions such as Red Baron tend to throw flower heads more readily than white skinned ones.

Another reason for onions to throw up flower heads is down to stress ... lack of water during the growing season is one of them.  Plants will go to seed as a preservation measure - during a drought, the plant will die but at least it will have set seed for the next generation when conditions are likely to be better.  Unless the bed floods during excessive rain/watering, then watering onions by and large should be fine when they are actively growing.  The stage when the plants are bulbing up but before they naturally die back is when you should stop watering completely (and hope we have dry late summer weather) - if the soil becomes wet at this point, the bulbs continue to take on water but don't always make for good storing onions.

If you snap off the flower head, it won't stop the process and it is unlikely the bulb will form properly.  This will affect storage.  So the best thing you can do is lift them up first and use right away, leaving the others to bulb up properly.