While weeding the mule garden this week, I discovered an unintentional polyculture.  I had pulled out all the seed potatoes from my fall potato experiment because they weren't sprouting --- or so I thought.  It turns out that one potato was overlooked, and it popped up between the leaves of a watermelon I'd planted at the end of the bed.

Meanwhile, my primary purpose for the bed was to plant fall carrots.  I seeded three different beds with carrots this summer, but very few seedlings came up in two of the beds.  However, in my polyculture bed, the watermelon took off and ran across the carrot area, shading the soil and retaining enough moisture for the seeds to sprout.  All three vegetables seem to be growing quite happily together so far, though I recently moved the watermelon tendrils aside to give the baby carrots room to grow.

In the interest of full disclosure, I have to admit that the carrot seeds in the other beds may have had shoddy germination rates because they were a different variety than those sown in the polyculture bed.  I usually have very good luck with Jung's Sweetness hybrid carrots, but the pack this year seems to have been a dud --- germination was low in our spring carrot bed too.  Next year, I might change my loyalties to one of the seed companies recommended by Steve Solomon.