long term investment: bonds v. stocks

So the interest rates are up. Let's say toward the end of the year the bonds would fetch 6%. I would be tempted to buy a bunch of long term bonds at this rate. The question is: if I hold bonds, do I need to show the realized interest every year or only when I sell them?

I am asking because I am in a pretty high tax bracket right now and want to postpone as much of realized income as possible to the point when I am retired.