Our first vegetable bed was a 12-by-24 monument to overreach. Everything we got wrong:
Too big, too soon
A 4-by-8 bed done well will teach you more than a 12-by-24 done badly. Half of our first bed went to weeds in July because we could not keep up.
We bought “good soil”
A whole truckload of “premium garden mix” that was mostly sawdust and broken dreams. We should have built it ourselves and waited a season. We know that now.
We planted what we wanted
Not what we would actually cook. Six kinds of squash. We hate squash by August. Two kinds of beans we never finished picking. The eggplants did nothing. The tomatoes did everything.
Year two is one small bed, six things, all stuff we eat. So far, perfect.

