I agree with Aaron the amount of increase is high in light of failing to raise rents in prior years. You should make a decision like the Lord of those two lands that you are and then notify the tenant's of their respective increases in writing as required by law.
Do not start with any "preludes" as you did here. The tenants should not be subjected to your guilty heart. It's frankly laughable that you're on a real estate investment forum asking for advice on raising the rents on your investment real estate, yet money isn't "driving" you or this entire inquiry.
I agree that good tenants are valuable in their own right and you should price the properties accordingly. But be firm, no backdoor outs like if one of the tenants disagrees and just make it a standard thing that you're going to increase rents 2.5-5% a year until you're 10% or so below what you're seeing in the market. I'd never take the two tenants you describe to full market rent - well that's probably a lie, but I'm unabashedly driven by money.