Why prune leaves at all?

Sprouts will first form at the bottom of the plant and continue forming upwards toward the top for several weeks. Brussels sprouts are ready to harvest when the tiny heads are firm, green, and 1 to 2 inches in diameter. Remove sprouts by twisting them gently until they break away from the plant.

As you remove the lower sprouts, it would be best to also remove any yellowing leaves; so the plant does not spend any energy in that area of the plant. As the Brussels Sprouts continue to grow upward, it will be producing more leaves and sprouts. The plant will withstand frosts and can be harvested until a hard freeze strikes. We have found that the best-quality sprouts are the ones produced during sunny days with light frosts in the night hours. As winter is approaching, you can trick the sprouts into maturing all at once by cutting off the top of the plant about 3 weeks before you want to harvest. In the production area of commercial growing of Brussels Sprouts, this trick is what they use to get their products to the market. One full-sized, healthy plant can bear between 2 to 3 pounds of sprouts. They will come quickly at first but as the weather gets colder the production will slow down. Full-grown sprouts will keep well on the plant as the weather gets colder, making them a great winter harvest item for gardeners in the South when they are planted in the fall. In cold climates, gardeners will often bury Brussels sprouts plants up to their tops in hay or leaves in late fall, then go pull off the little sprouts as needed during the winter. You can store fresh unwashed sprouts in plastic bags in the refrigerator. Fresh sprouts taste best, so limit refrigeration to a day or two.

I harvest the sprouts from the bottom up when needed. I may only pick 6 -10 sprouts from each plant at a time. (I like them smaller, about the size of small superball) As I pick each sprout, I remove the leaf where it was attached. Some say to lop off the top at some point to force the sprouts to mature faster or at the same time (not sure about this exactly). I've never done this, as I just let it keep on growing up as I pick the lower sprouts. As of right now, my spouts plants look like giant lollipops growing out of my garden! lol. Best of luck with your plants.

This is what I'm talking about

http://urbanext.illinois.edu/veggies/brusselssprouts1.html

"Some gardeners believe that the sprouts develop better if the lowermost six to eight leaves are removed from the sides of the stalk as the sprouts develop. Two or three additional leaves can be removed each week, but several of the largest, healthiest, fully expanded upper leaves should always be left intact on top to continue feeding the plant"

The way I look at it is the plant knows what it needs. It produces leaves to make food from photosynthesis. If the plant has no use for the leaf it will cast it off. If the leaf is green, it's working and benefiting the plant.

Removing leaves can only reduce the plant's energy so I don't see the point. I don't think removing a few leaves really harms the plant in any noticeable way, I just don't see the purpose or what benefit it would provide.

I have never removed any leaves from mine and I have never had any good sprouts. This year I remove some leaves.