When creating new garden space via sheet mulching it is always advised to wait at least a few months for the bed to start decomposing before planting into it. However, each year we find ourselves wanting to plant more space than we have prepared. We inevitably decide to do some more sheet mulching, knowing that we can plant right into it with the old stand-by- winter squash. It is a bit of a pain to cut through freshly laid cardboard, but winter squash seems to do just fine. We have chosen to use them as pioneer plants in fresh beds because they are large transplants which need a lot of space, therefore you are making less holes than other fine seeded types of plants. Winter squash also likes a lot of fertility, and grows quickly to cover and smother the area. We rarely have to weed a winter squash planting in fresh sheet mulch. The good leaf cover helps to discourage weed growth and by the following year the beds are in pretty good shape for other crops. Some years we have planted garlic right after the winter squash.
This year we used winter squash in 3 different types of new beds: swales dug by hand then planted, cardboarded and mulched, a fresh sheet mulch, and a terrace that was newly finished. More details about the swale planting can be found here on a previous post. This is what it looked like in August. The white blooms are from daikon radish gone to seed. It was seeded into the swales along with various types of clover to cover the ground, add nitrogen, and in the case of radish to make water penetration easier.
For two years now we have also tried planting sweet potatoes into fresh sheet mulch, and the results haven’t been half bad. As far north as we are near the top of Vermont, we don’t expect to get a lot from a warm loving crop like sweet potatoes- especially without using black plastic to warm the soil. We were pleasantly surprised both years by how many sweet potatoes we got, though not enormous, even with all that mulch that most people say keeps the soil cold. They also have the spreading vines that smother and cover a new area. Next year we won’t put pumpkins next to sweet potatoes though- a little too much smothering and covering of each other went on.