To harvest or not to harvest?

[Fillerup]

I have tried 5 different types of weed and 4 plants are close to, or at harvest time. I wanted to know if the top cone looks ready and some buds as well, can I cut them and allow the rest to grow or will it kill the whole plant?

[AeroTX]

Don't just cut it off because it "looks ready" because there may be more growth and potency yet to come. Go to radio shack and get a 10 dollar handheld microscope and check the trichome content and color.
http://www.marijuanapassion.com/forum/showthread.php?t=1938

To answer your question, I have harvested some buds without cutting too much of the plant, and the smaller buds did continue to grow. Take a look at that link because you can get different highs and make sure that it doesn't just look ready.