Jimsom weed (Datura stramonium), beloved of the 60s hippies, is an annual plant that is native to Mexico, but has spread all over the world.  It is a member of the nightshade family which includes eggplants, peppers, tomatoes, potatoes and tobacco. 

Like other members of the nightshade family, jimsom weed is poisonous.  All parts of the plant are poisonous, so be careful when handling it.  It contains atropine, scopolamine, and hyoscyamine.  In tiny doses, they can be used to treat asthma, muscle spasms, and Parkinson’s disease.  Higher doses cause hallucinations and even coma.

Higher temperatures caused by climate change results in higher concentrations of carbon dioxide in the air which will increase the toxicity of jimsom weed.  Again, be very careful handling this plant.

Jimsom weed needs full sun.  It prefers rich, moist soil, but will grow in almost any kind of soil.  Richer soils will result in larger plants.  The plants grow 1 to 4 feet in height and 1 to 4 feet around.  Once established, the plants are drought tolerant thanks to their long tap root. 

The stems are a mix of green and purple.  The leaves, which are 6-inches in length and serrated, are arranged alternately on the stems.  They are dark green and have a stinky smell when crushed which keeps animals from eating them.  There are actually more accidental poisonings among humans than animals thanks to that smell.

The flowers are trumpet shaped, up to 4-inches long.  They are white, tinged with purple.  They open at night.  The sweet fragrance, attracts nocturnal moths, especially the Sphinx moth.  The flowers only last one night, wilting by the next morning.  Bloom time is July through September.

The seed pods, which are about the size of a ping pong ball with scary looking spikes, start out green turning brown as they mature.  Each pod has four chambers and contains 600 – 700 black, kidney shaped seeds.  Each plant can produce up to 50 seed pods. The pods mature and release their seeds 30 days after pollination.

Jimsom weed is a prolific self-seeder.  If you do not want these plants all over your yard and garden next year, remove the seed pods before they mature, turn brown and release their seeds.

Jimsom weed is easily grown from seed.  If you wish to sow the seeds directly into your garden, wait until the soil has warmed after your last frost.  The seeds will not germinate in cold soil.  Plant the seeds ¼-inch deep.  Keep the soil moist.  Germination will occur in 7 to 21 days.  Thin your seedlings to 3 feet apart.

If you want to start your seeds indoors, you can do so 6 to 8 weeks before your last frost.  Plant them ¼-inch deep in sterile seed starting mix.  Warmth is key.  Use a heat mat to keep the soil at 70°F to 80°F.  Use a mister to keep the mix moist.  Germination will occur in 7 – to 21 days.

You can move your seedlings outdoors into your garden after the soil has warmed after your last frost.  Space them 3 feet apart.