How can I grow asparagus in a 4×16 feet box? I will be insulating it with leaves in the winter.
Plant Zig Zag in rows about 12 “ – 15” apart. Water heavily but do not over-water. Mulch them to conserve water and keep the weeds down and the plants on the cooler side. Cover the crowns with 2” of soil and as the ferns grow gradually fill the hole with soil, adding no more than 2” at a time.
Asparagus plants are heavy feeders so add compost every year and do not pick for two years – just sneak one or two to see how they are doing but not a full harvest. Don’t cut the stalks till they turn brown in the fall and they can be composted. At that point, you can add more compost to at least an inch thick over the bed. Add a layer of straw mulch to protect them for the winter, or a layer of thick leaves. Do not use oak leaves, as these do not break down readily. Also, do not mulch the asparagus bed till the ground is fully frozen (usually in December) and not just cold as if the ground if not fully frozen it will stay that way all winter and that happens.