I am a landlord with a 'skip' who owes for June and also dumping belongings on my property as well as not cleaning before they left. I understand I can go to small claims court and I am certain I'd win judgement, but there are no guarantees that a collection agency thereafter will collect what is owed. Can I have their wages garnished?

Yes

I am a landlord with a 'skip' who owes for June and also dumping belongings on my property as well as not cleaning before they left. I understand I can go to small claims court and I am certain I'd win judgement, but there are no guarantees that a collection agency thereafter will collect what is owed. Can I have their wages garnished?

You have to take it to court first... and win.. then you have to get a writ of garnishment from a court based on that judgement.

Its up to you to find their bank accounts and jobs to have them garnish it however.

This is a reason why you get references and job info before you rent.

But, as noted, if you win, you can use garnishment to collect if you can find where they work.