is it boxing day to sow onion seeds or just sets?

[bluemoon]

It is supposed to be Boxing Day, but I love that day, it always seems to be the one where you can feel the true spirit of Christmas once all the mercenary gift giving is over, but the family are still around. Number one son's birthday is the 28th, these days it means his mates start descending around lunchtime in readiness for their big night out (well they've got to have some excuse, it's a long time between Christmas Eve and New Year's Eve) Anyway I tend to use the dire urgency of sowing the onions as an excuse to escape to the greenhouse for an hour. I think the reasoning behind it is that onions are day length sensitive, so you sow them as soon as the days start to grow longer.

[Matt.]

For onions, 29th or 31st

Whats wrong with the 30th? Is this a bad lunar day? I remember my old book had these every now and again due to the moon aligning with something...

Also can you dry sow the seed early and then water on the day you really want to sow. I.e. Sow the seeds in dry compost at the weekend (when I have time) but only water mid week when the lunar time is right? Do you think you'll still get the same effect?