I sent the info on watering via e-mail a moment ago. Now regarding the other parts of your question. Pinching flowers is not needed. They will drop their own blooms but if you like you can remove any dried remnants that are left on the plant. Humus is decomposed organic matter and is good for plants but doesn't have the nutrient content concentration of a fertilizer such as Miracle Gro. Fibrous rooted begonias are annuals while tuberous rooted begonias are perennials. Don't worry about "stupid" questions. Gardening is a life long learning process and we welcome your questions!
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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