We like growing vegetables, but we also enjoy decorative plants. So our garden has always been a bit eclectic. You’ll rarely see a long straight row of identical plants. It makes cultivating a bit more tedious, but we like the results.
There are additional benefits to intermingling plants, beyond the purely aesthetic: soil volume is used more efficiently by combining shallow-rooting with deep-rooting plants; beneficial properties of one plant (e.g. alliums discourage some pests) can help others; minimizing exposed soil reduces weeds, improves soil structure, and retains water.
This year we were a little more adventurous and have definitely seen some successes: barley grass sown in between newly planted perennials protects the soil until the new plants are established; clover provides a living mulch in our little stand of corn, while also being a nitrogen fixer; wormwood and other herbs deter pests or attract beneficial insects. Of course there are missteps along the way: cabbages planted in the garlic patch were ravaged by slugs – presumably because they were the only tasty thing in a desert of alliums; and clover undersown in the potato patch did not survive hilling.
The results have been mostly encouraging though, so we’ll be doing more experiments with other plant combinations.