Applying a lawn starter fertilizer is vital to provide the seedling with the nutrients needed to germinate and grow. Also, it increases the number of grass seedlings that will survive in the future. However, many lawn owners are unsure whether to fertilize or overseed first. Fertilizing your lawn a few days before or after overseeding is essential to feed your new grass seed. You can implement either of the tactics if you want a lush lawn. Besides, you can spread the grass seed and apply a starter fertilizer simultaneously to boost the growth.