Rhys, you are referring to saving seeds by moon position, which is fine and has happened for centuries if not millennia, bit it is not biodynamics. That developed after Rudolf Steiner’s 1924 lectures at Koberwitz, where moon phases were a minor part of his wide-ranging recommendations. I know of biodynamic farmers who barely use a moon calendar, concentrating on good husbandry.
The seeds I saved last summer and sowed in early February all had a 100% germination rate and came through within 4 days!
Alicante, Shirley, Tigerella, Maskotka are doing quite incredibly well so far, the Black Cherry is pretty good too. The Riesentraubes are slower but look very healthy,
In 2015, there are actually two windows – the weekend 15/16 August and Friday/Saturday 11/12 September…..