I have always potted-up my large-flowered begonia plug plants in those trays of module cells - 15 to a tray. I know that a few always bite the dust but this year there is quite a variation in size. Some have grown well for this time of year, but some are still quite small. This year I used John Innes No. 2 and earlier on gave them a feed with dilute Tomorite as a little boost. Why does this happen?
Leftover chicken, veggie rice with fridge gravel clear out stuff and some hm spicy beans I found in the freezer when I was looking for something else. Basically a mix and match of things that needed to be eaten and it went together surprisingly well
As a precaution just sow a couple more seeds to grow on. My last sowings of cucumber will be in early June and they will still produce a good crop later in the year (as good as earlier spring sown seed). These are grown under glass but I guess there would be no difference if grown outside assuming they were of the right variety.
Over winter I tried a mixture of Marmite, Plain Flour and Sugar mixed with warm water in beer type home made traps. They caught hundreds of slugs especially the little black underground ones that you don't see during the day. No reason to think dried yeast won't work. The mixture does start to ferment after a few days especially in warmer weather.