An adjustable hand trowel comprising a handle, a blade-neck assembly comprising a blade and a neck, and an adjustable fastener system is disclosed herein. The adjustable fastener system provides a secure method of fastening the blade-neck assembly to the handle wherein the adjustable hand trowel is able to withstand forces typically exerted when using a trowel for digging and wherein the user may readily dig in confined spaces. The disclosed adjustable hand trowel further allows a user to adjust the relative position of the blade and handle using an adjustable fastener system that may be operated using one hand. The adjustable hand trowel may thereby allow the user to dig in an ergonomic and efficient manner in applications that would otherwise be unsuitable for ergonomic and efficient digging.