You'll want those flourescents at 4-6 inches from the soil. I assume they are 4 foot since your box is 4 feet long. Spinach prefers it cooler than the herbs. You can set them out quicker. The herbs (other than parseley) can't go out until no frost date. Good Luck ~tom

I was bored and wanted to experiment so I began some lettuce under a really cheap shop light in the basement. Well I have to tell you it worked out great! I have been able to eat a small salad 3-4 times a week. See my blog below for pictures. Kim

Here is a link that might be useful: my blog

You may find it difficult to germinate spinach seeds indoors, especially if you are warming the soil. I've had much better success sowing spinach outside, even if the soil is cold. Most veggie seed will germinate faster with warmer temps, but spinach is not one. It prefers cool conditions to germinate. I'm thinking 55-60F is ideal. Just something to think about.