I planted a much smaller garden last year in my dirt (with a small bit of the rotted leaves), and managed a mediocre harvest with the exception of this tomato plant that I did not sow.
This year, as a means of experimentation, I kept the garden very small (shown below). I planted a few beans, 4 watermelons, and about 8 tomatoes, all in nothing but the rotted leaves. All but one tomato are in buckets (also below), the other in the garden.
|My small garden, about 2' x 10'. You can just see the watermelons between the beans.|
|My bucket tomatoes.|
The garden area, however, is not growing as expected, but I think I know why: 1) the layer of leaves is not very deep, which may be hindering root growth; 2) I did not use any row cover for the watermelons as in years past. Watermelons like heat, and I do not think they are getting enough in this weird cold May weather; 3) the leaves by themselves do not hold water very well if at all, unlike mulch. In the buckets, it seems to have compacted a bit and holds the water good (doesn't hurt that the buckets have no holes in the bottom either). Again, the shallow layer of leaves may contribute to this as well.
So that is my garden as it stands now. Will report back when the tomatoes begin to flower.