I split the tunnel in two. One side has tomatoes, cucs, aubergines,peppers. The other, early potatoes, carrots, mizuna, mispoona,radish rocket, mustard greens lettuce,spring onions, early french beans,early cabbage, calabrese.
Tomatoes and peppers are sometimes still cropping at winter solstice. As soon as I take the toms out I prep one bed for early potatoes.In late feb the potatoes go in under thick fleece. I know this doesn't sound like good practice in terms of rotation but my theory is that the potatoes are done by the end of May, so the bed has had the nightshade family in for only one full year. I have four beds so potatoes only get grown once every four years in the same bed. Each bed has a break for a full year from tomatoes . I have been doing this for six years now and haven't seen any problems.
Once the spuds are done, I sow carrots(really struggle to grow carrots outside here because of clay soil and carrot fly) and early french dwarf beans successionally.When these are done, (about now), I sow over wintering salads. They will come out when it is time to plant the tomatoes again. So yes, triple cropping is definitely doable.
I try to keep the soil in good health,feeding with good compost as a mulch, and try to manitain a degree of rotation. And keep experimenting!
