Gnomes live outside year-round, so a little care keeps them looking good for years instead of fading after one season.
Resin and plastic gnomes hold up well but can fade in strong sun — a UV-protectant spray (available at most hardware stores) slows this down significantly.
Ceramic and terracotta gnomes are more fragile in freezing climates, since trapped moisture can crack them. Bringing these indoors or into a shed over winter is worth the extra step.
Painted gnomes benefit from a clear sealant coat, which protects the paint from rain and sun without changing the look.
A quick rinse with a garden hose every few weeks also keeps dirt and algae from building up, especially in shadier, damp corners of the yard.