Absolutely nothing - but be civil. Smile politely, excuse yourself and get about your business. If her sons say "that's how she is" then they know she ain't changing.
How old is she? Set in her ways - as they say? Maybe, she's just alittle jealous that her sons are still at home and not off on their own! Whatever, unless she's paying you as a psychiatrist, it's not your problem to solve. Just always be civil but excuse yourself and get away from her.

thank you for that advice.i tried that already and she seems to find me whenever i'm outside. if i just go into my house she says that I'm avoiding her hence I killed her plants.just sick of telling her that i haven't done that and to tell me to "get out" i think that's just wrong.how do i bother her when i work everyday from 8-5pm? just want her to stop accusing me of doing things. she's in her 70s..
thank you

tell her VERY FIRMLY to leave you alone.

If this behavior has only recently started, then she may need to be evaluated for mental or physical problems. She sounds ill to me. If she's been that way for the 3 years and she ain't changing.

Have you tried buying her another plant like the one you "murdered"?

Just appologize for everything she accuses.
You politely win everytime she wins.

Sounds like she's either angry over things you can't help her with or she's got some mental problems, perhaps dementia. It sounds like a bad situation. mrsd 1957 has a point...maybe she's bitter that her sons are still living at home and so she is projecting her anger at you. Unfortunately all you can do is try to get away from her when she's ranting. Tough spot...

It sure does sound like early stages of dementia. In that case, nothing you say or do will make any difference, and it's best not to argue or debate with someone with that condition. Just remind yourself that she likely can't control it, and it's not your fault.

I was going to say this does sound like the beginnings of dementia. A friend of mine had a problem with a neighbor that escalated to the point where she (neighbor), was calling the police to say that my friend was trying to kill her, and was breaking into her home regularly; was coming out of the television, etc. I cannot tell you how much of a wreck my friend was over this. She was afraid to go outside as the neighbor would scream when she saw her. She was almost stalking my friend; watching out the window and waiting for her.
Eventually, my friend moved out of the house she shared with another roommate and moved home with her parents for a while until she felt the situation had calmed down a bit.
My suggestion to you would be to keep a log of all the confrontations you have had with her; when you've spoken to her sons, dates and times. That way if she calls the police on you or accuses you of something, you have some documentation of what has been happening.
If you have another run in with her, I think I might pay a visit to the police to let them know what is happening and what your concerns are. I would think it would be better to be the first one to let the police know there is a potential problem, rather than wait for her to accuse you of something. That is the problem my friend had. She let things go for months, preferring to just ignore the neighbor when she accosted her outside. When the neighbor began complaining to the cops, the first few visits the cops made my friend feel they were taking the side of the crazy neighbor. Eventually, the cops came to realize the lady was developing dementia, and were sympathetic to my friend. But having the cops show up at my friends door for all types of crazy complaints did take it's toll on my friend. Best to be safe and prepared.
Good luck

thank you for all the advices..
I had another discussion with her son and he had apologized for her behaviors.he will talk to her regarding this matter. hopefully that will ease up some of the tension between us. well....i was thinking about talking to cops about this but i'm not sure what they can do about it....right now all i can say is she think i killed her plant...not so sure what the cops are going to think..thanks again

DO NOT take this personally. I know that sounds crazy but my mother-in-law was bipolar and believed everyone was out to get her(even me). Nothing you can say or do will change anything if she has a mental illness or dementia.
I agree with the smile politely and go about your business. You can try "killing with kindness" but no guarantees there.
The police can not do a lot for her or for you for that matter.
Try to stay positive and polite and know she is the one with the problem not you. Believe me I know it isn't easy but at least you don't have to share Christmas with her.