BUT... not organised as I should be.

But it is useful to keep in mind that tenants are people to, and you can save yourself a lot of headache by just treating them as human beings instead of unwanted squatters in your property.

Now if they pay even more when they stay, now that could improve NOI, but I don't see it happening ...Rochelle:Steve is even more cynical than I at times ;-)   If you simply set aside a piece of the property and allow the tenants to garden there, there is no real cost to you and the goodwill could keep tenants longer term.An alternative is to see if there is a urban gardening business/co-op/organisation in your area who would {preferably} rent the plot from you (auxiliary income) or come in and work it for free (an organisation) ... with either approach you could make involvement of your tenants who wish to garden a condition of any arrangement.This may be a nice perk for 10% of your tenants, but do not let it distract you from the main job to get done.

See what they recommend they do and stress that this is not a landlord tenant situation, it is an unwanted guest in a private residence not leaving the property.

Prep all materials in advance and if you are well organised it should only take a few hours. 

We have several student accommodations and the prime lease-up windows are late February - April (for those who are very organised and looking for a lease starting in May or September) and June - July (for those who are less organised, or were accepted in to a programme last minute).

I have done this with a volunteer organisation, which is where I learned the process.  

Then, eventually, it goes to a mandatory mediation session, where you could tell them you didn't feel it would be right to put an all female household potentially at risk with an unwanted male roommate.  

Try to do this with very short notice so she won't have time to clean up, or shoo an unwanted live-in boyfriend, etc.

You should probably fix it as fast as you can as a broken window could be a point for unwanted entry.