Savvy gardeners have long observed that certain vegetables and herbs will grow better, or worse, when planted near certain other types of herbs and vegetables. This practice, known as companion planting, is another way to help your vegetable garden produce as much as it possibly can.
Carrots and parsnips have similar growing conditions and can be planted side by side. Because they can take up to 28 days to germinate and are slow to get started growing, carrots and parsnips are often interplanted with radishes. The fast-maturing radishes will germinate, grow, mature and be ready for harvesting by the time all of the carrots and parsnips have germinated and the seedlings are ready for thinning.
The three sisters of corn, pole beans and squash are a great example of companion planting. Plant the corn in a grid pattern. After it germinates, sow three or four seeds of pole beans in a circle around the individual corn seedlings. As the corn grows it will support the pole beans as they grow and mature. Finally, sow a pair of squash seeds at least 6 feet apart and evenly spaced in the growing bed. Their rambling vines will create a living mulch that will shade the soil, conserve moisture and check the growth of weeds.
Cucumbers and Melons
Cucumbers and melons also grow well together in the vegetable garden. They are both vines and will either scramble along the ground or climb a support structure. Cucumbers and melons prefer hot weather and shouldn't be planted until after all danger of frost has past and the soil has warmed up completely. Due to the high water content of their fruits, both cucumbers and melons require a lot of water when their fruits are developing and ripening.