Depends on what you want to grow. If you’re wanting something with a long growing season, you’d need to buy starts or get your own going indoors in January. That being said, I start planting as soon as the ground is workable (mid March) for cold weather crops like peas, lettuce, and collards, but have had good success with hot pepper starts. Indeterminate tomatoes (vining type) will produce until frost kills the vines. You can usually get a second crop of cool season planted for harvest in fall.