Intercropping involves growing an additional crop in the spaces available between the main vegetable crop. This could be a fast-growing crop, such as radishes, grown at the same time as a slow-growing crop, such as parsnips. This means that the radishes can grow and make use of the available space, but are harvested before the parsnips need the additional room. Other examples include planting a deep-rooted crop with a shallow-rooted crop, or planting a tall crop with a shorter crop that requires partial shade.

This technique allows the vegetable gardener to produce a greater yield on a given plot, by making use of space that would otherwise be wasted with a single crop. Intercropping can also encourage biodiversity, by providing a habitat for a variety of soil organisms and insects that would not be present in a single crop environment.

However, careful planning is required, taking into account the soil, climate, crops and varieties, so that crops do not compete with each other for space, nutrients, water or sunlight.