Right. You might want to harvest some parts of your plant before others. I spent this summer growing veggies, and to be honest, cannabis is that same, just different. With veggies, there are peppers or tomatoes that will ripen before other ones. So you pick the ripe ones first. You let the others grow a bit longer. Cannabis is the same way. The ones closest to the lights, will most likely mature to your liking first, check the trichs. So harvest those. Let the others grow a bit longer, week or so. Then if they look ripe, harvest them. There is no rule or law that says that you have to harvest the whole plant at once. Snip your top cola's first, if they are ready first, let the buds on the stem grow a bit longer, then take them. At least that is what my growing experience with veg's has shown me. All plants are the same. Just different strains, kinds, etc.