When should I fertilize my lawn in Michigan, considering the region’s unique climatic conditions and varying soil types? Are there specific benefits to timing the fertilization process precisely around the onset of spring? How do temperature fluctuations, moisture levels, and grass types influence the optimal timing for this crucial lawn care practice? As I contemplate the nuances of lawn maintenance, should I also take into account the stages of grass growth and potential weed competition? Moreover, is it advisable to conduct a soil test prior to application to ascertain nutrient deficiencies and tailor my fertilization approach accordingly? Are there particular fertilizers recommended for the Michigan climate that could enhance the vitality of my grass as it emerges from winter dormancy? Ultimately, what are the specific indicators I should observe to determine the most suitable moment for fertilizing my lawn, ensuring a lush and vibrant landscape throughout the growing season?