Permission to enter yard?

[Karen S.]

I have a fourplex and the 2 downstairs units have their own small yards. One of the tenants asked if I could have a big tree in their yard chopped down because she thinks there may be a wasp nest. I hired a gardener to come and remove the tree and peeked next door at the yard and it was covered with tall weeds so I asked them to go and pull out all the weeds and spray weed killer. The tenant found out that all the weeds were pulled and that I did not give him notice about anyone entering his yard. This was in the end of June and on Oct 8, he called the Police Dept to file a report that his garden tools were stolen and he said that I purposely had someone come in to take his things to harass him. Should I have gotten his permission to enter the backyard?