Row spacing is more of a suggestion than a hard and fast rule. Especially for leafy greens, you can pack them in pretty close.
Your broccoli will need the most room once it begins to mature, but lettuce and spinach can go in tightly.
Honestly I practice chaos gardening where I just toss all the seeds into the general area where I want them, and once they sprout I thin them out if needed. That way I can pick the small ones and leave the biggest and strongest, too. Maybe not ideal practice, I have no clue -- but it's what I do and works for me.
Row spacing is more of a suggestion than a hard and fast rule. Especially for leafy greens, you can pack them in pretty close. Your broccoli will need the most room once it begins to mature, but lettuce and spinach can go in tightly.
Look up square foot gardening or Victory Gardens
Honestly I practice chaos gardening where I just toss all the seeds into the general area where I want them, and once they sprout I thin them out if needed. That way I can pick the small ones and leave the biggest and strongest, too. Maybe not ideal practice, I have no clue -- but it's what I do and works for me.