How Big Should My Tomato Seedlings Be Before Transplanting?
Tomato seedlings should be approximately 6 to 8 inches tall with a stem diameter of 1/4 to 1/2 inch before transplanting. At this size, they will have a well-established root system and sturdy stems to tolerate the stress of being transplanted. It is important not to transplant seedlings too early as they may not have enough strength to survive outdoors and can be easily damaged or killed.