In Delaware a lease automatically rolls to a month to month lease if no renewal is signed and 60 day notice is required to vacate (or to give notice to move)  If you prefer to have it vacant in the summer then give her notice to move and not leave it to chance. 

If you were trying to remove this tenant from your property, would you:Give 30 days notice that you're not renewing his lease next month and ask him to leave? 

I would plan to sell this property when the tenant is no longer ready to renew.

Last time I spoke with him he wanted to be sure I was staying another year when my lease renews in July and promised to only raise rent $25, which he held true to.

That being said, I'd rather delay for a "sure-fire" method (lease non-renewal), rather than do something reckless in a way they could defeat or push back in court, if it came to that. 

Clearly state whether there is an Option to renew. 3.

Common fees will include a set-up fee, a leasing fee for each turnover or a lease renewal fee, marking up maintenance, retaining late fees, and more.

We are now having to involve the tenant as her lease is coming up and if we can't get the balance paid up to date then we are going to have to give her a 60 day non renewal letter. 

While the easy explanation is that you have a superior property, from the appraiser and bank's POV, I could see them arguing that you will not be able to renew at that rate, and since your loan is outstanding longer than this lease term, they should not underwrite entirely to an above market lease rate.  

I know insurance in the foothills with timber etc and threat of wildfire has gone up all through the west.. but we are in Lake Oswego which is an urban environment.. when I got a renewal.. my insurance went from under 2k a year to over 6k a year..