Tip growth in walled cells is regulated by a spatially confined yielding of the cell wall under the effect of the turgor pressure. This mechanism is displayed by a variety of cell types such as fungal hyphae, pollen tubes and root hairs. The common feature of these cells is their ability to invade a substrate or matrix. Here we review the cellular and biomechanical underpinnings of tip growth compared to growth in other walled cells. The physical challenges associated with an invasive life style are assessed and explained.