Poetry is known for saying so much with so little. In prose, we can have a tendency to let our words run on until we find the description we want, but learning to be concise can make for a much tighter novel and more effective prose. The sensory details of poetry will help you build settings and scenes with short, evocative descriptions. Symbolism is crucial to poetry and can add an extra level to your prose when you learn to use it. Foreshadowing and creating emotional states can be done through objects or precise word choices. The symbolism and brevity of poetry will teach you to do things like that.
Read it or write it, but start putting poetry into your literary arsenal. Try working with specific forms like haiku, limerick, or sonnet. The confines of a structure will hone your language skills through challenge. You'll find yourself learning new words and bending old words into symbolic usage. For one month, write a poem a day. Let them be bad, but see how it changes your writing in general.