It’s usually legal to grow Datura at home. Just be aware of the high risk of poisoning to pets and small children. Sometimes just handling the plant is enough to cause toxic effects. 
 Arnett, A. M. (1995). Jimson Weed (Datura stramonium) Poisoning. Clinical Toxicology Review, 18(3), 1-6.
Atropine, scopolamine, and hyoscyamine/daturine (the l-enantiomer of atropine) are the primary active constituents in all Datura species. As tropane alkaloids, they’re structurally related—each have a seven-membered tropane ring with an N-methylated nitrogen bridge, and a propionic acid chain substituted at R2 with an aromatic phenyl ring and R3 with a hydroxyl group OH-. The tropane ring and acid chain are connected at R3 and R1 via an oxygen atom. 
Treating an atropine or scopolamine overdose usually involves swallowing activated charcoal to delay the absorption of the alkaloids, as well as injecting physostigmine intravenously. Physostigmine is effectively an antidote to Datura, crossing the blood-brain barrier and agonizing the affected muscarinic acetylcholine receptors. Unfortunately, its activity is relatively short-lived and not suitable for people with heart problems.  
 Furey, M. L., Drevets, W. C. (2006). Antidepressant Efficacy of the Antimuscarinic Drug Scopolamine: A Randomized, Placebo-Controlled Clinical Trial. Archives of General Psychiatry, 63(10), 1121-1129.
In traditional cultures, a great deal of experience with and detailed knowledge of datura was critical to minimize harm.   Many fatal incidents result from modern users ingesting datura. For example, in the 1990s and 2000s, the United States media contained stories of adolescents and young adults dying or becoming seriously ill from intentionally ingesting datura.   There are also several reports in the medical literature of deaths from D. stramonium and D. ferox intoxication.    Children are especially vulnerable to atropine poisoning and their prognosis is likely to be fatal.  
There can be a 5:1 potency variation between plants and a given plant’s toxicity depends on its age, where it is growing, and the local weather conditions. This variation makes datura exceptionally hazardous as a drug and there is no way for the common man to accurately measure the dosage of any given plant. Datura has been used for centuries in some cultures as a poison because of the presence of these substances.  
The safest way to prevent overdose is to grind the dried plant matter into an extremely fine and even powder so that the active chemicals within them are distributed evenly across itself. From here, one can slowly work their way up in extremely small increments until the correct dose for that particular plant is found.
Datura has been reported to cause psychosis and delirium at a significantly higher rate than other hallucinogens like LSD, ketamine, or DMT. There are a large number of experience reports online which describe states of psychotic delirium, amnesia, and other serious consequences after abusing the drug. In many cases, it has resulted in hospitalization and death.
In some parts of Europe and India, datura has been a popular poison for suicide and murder. From 1950 to 1965, the State Chemical Laboratories in Agra, India investigated 2,778 deaths caused by ingesting datura.   
Datura (also known as devil’s trumpet, moonflower, jimsonweed, devil’s weed, hell’s bells, thorn-apple, and many others) is a genus of nine species of poisonous flowering plants belonging to the family Solanaceae. Daturas are known as powerful and dangerous deliriants, used for shamanic and medical purposes, as well as poisons. They contain the potent anticholinergic substances scopolamine, hyoscyamine, and atropine primarily in their seeds and flowers. 
Anecdotal reports which describe the effects of this compound within our experience index include:
Simmat, G., Robert, R., Gil, R., and Lefevre, J. P. [Attempted suicide by ingestion of Datura stramonium seeds]. Presse Med. 10-29-1983;12(38):2399. View abstract.
Spina, S. P. and Taddei, A. Teenagers with Jimson weed (Datura stramonium) poisoning. CJEM. 2007;9(6):467-468. View abstract.
Fretz, R., Schmid, D., Brueller, W., Girsch, L., Pichler, A. M., Riediger, K., Safer, M., and Allerberger, F. Food poisoning due to Jimson weed mimicking Bacillus cereus food intoxication in Austria, 2006. Int J Infect.Dis. 2007;11(6):557-558. View abstract.
Diker, D., Markovitz, D., Rothman, M., and Sendovski, U. Coma as a presenting sign of Datura stramonium seed tea poisoning. Eur J Intern.Med. 2007;18(4):336-338. View abstract.
Rissech, Payret M. and Garcia, Tornel S. [Datura stramonium poisoning]. Med.Clin.(Barc.) 11-25-1979;73(9):397. View abstract.
Alebiowu, G., Femi-Oyewo, M. N., Elujoba, A. A., and Ojo, O. S. Toxicity studies on Datura metel L. with reference to official stramonium. J Herb.Pharmacother. 2007;7(1):1-12. View abstract.
Germond-Burquier, V., Narring, F., and Broers, B. [Intentional datura stramonium intoxication and circumstances of use in two adolescents]. Presse Med. 2008;37(6 Pt 1):982-985. View abstract.