Yes, there are plants that get you high and are legal to grow. There are many plants that are found in nature that will do just that. Do remember that this article is not endorsing any particular plant nor does it guarantee what the results of these plants will do for you and if they will actually get you high.
Datura
This plant is also known as Jimson Weed. It can grow up to two meters high and is a leafy herb. It can be identified by the large purple or white flowers and produces seed pods. It contains chemicals that are located mainly in the flowers and seed pods. These chemicals include: Atropine, Scopolamine, and Hyoscyamine.
When the flowers and pods are ingested that can cause effects that range from euphoria and hallucinations to delirium and confusion. The effects can last up to three days if ingested in large doses.
Morning Glory
The seed of this flower has a psychedelic very similar to LSD and contains lysergic acid amide (LSA). The only difference is that it only has about one tenth of the strength of the psychedelic abilities of LSD. Most of morning glory seeds that you buy to replant are coated with a substance that is designed to make you sick. You need either to find untainted seeds or extract it from the tainted seeds. The best ones are the blue or purple ones. It will produce a dream like state that can last up to fourteen hours.
Salvia Divinorum
This is a psychedelic which contains Salvinorin A and can give you a intense ten to thirty minute trip. The effects can range from an extremely intense experience to radical perspective shifting. There are many people who have tried this and do not want to try it again but if you want to try it, this can be bought legally online in most of the United States.