how many times do you have to spray with soap and pepper and when is the proper time,spring? while flowering?

I assume you are trying to get rid of insects. I would suggest you spray whenever you see the insects. I would use liquid hot sauce, but, you don’t have to use hot sauce. Mix a couple tablespoons of powdered hot mustard with a quart of water. Mix in a cup of mouthwash (Listerine) to make your spray especially nasty. I’ve even heard that adding a can of beer also chases the bugs away.

I’ve never used this spray for flowering trees, but have used in on my lawn and it does no harm to the grass.