My tenant is leaving soon cause it’s the end of the lease and she didn’t renew.

That prevents a tenant from getting too far behind and limits the amount of effort I need to put into a renewal. 

Also when your lease is up for renewal , expect it not to be renewed , or a rent increase probably $400 a month 

If that is the case, does your lease say that if a tenant holds over the lease renews on a month to month basis until notice of termination is given by either party, and you have properly given such notice?

You can give notice that you don't want to renew by ?

After the 5th, a $50 later fee will be charge.Initially, we offered to renew their lease when it expired on December 31.

The seller never renewed any leases in his 30 years of ownership.

Then when the lease is up for renewal, increase the rent to market value. 

But I seem to rent quicker and get a premium on rent if I market from early spring to mid summer.Does anyone else experience the same seasons and do you try and make sure your leases renew during a good rental time? 

Getting started in real estate, my funds are a bit strapped with fees, renewals, memberships, etc but sales are not as expedient.