The most intensive type of vegetable gardening is generally considered to be vertical gardening. Vertical gardening involves growing plants upward on trellises, walls, or other support structures to maximize space and increase yield per square foot. This technique allows for the cultivation of a large number of plants in a small area, making it ideal for those with limited space or urban gardens. By training plants to grow vertically, gardeners can optimize sunlight exposure and airflow while also reducing the risk of pests and diseases.