She talked to you about pink snakes strangling invisible cows and also has tried to strangle the landlord? Eeeyikes. You be careful around her.
Edgar - people often assume such stuff in old people is dementia or some other pretty untreatable thing.
However - she MIGHT be suffering from something like a psychotic illness, or a very severe depression (which can sometimes lead to psychotic symptoms - though she sounds more hypermanic than depressed!) - or something physical which might respond to treatment - like reduced oxygen flow to her brain.
Are you in a position to suggest a proper psychiatric/geriatrician assessment? To family - or via apartment manager?
Molasses on some of the plants?