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Datura are herbaceous annuals and short-lived perennials in the tomato family (Solanaceae) with a confused taxonomy and disputed origin because of their extensive naturalization through temperate and tropical regions world-wide. Of the eight or nine species in the genus Datura, many naturally exhibit extreme variability in foliar and floral characteristics and many are very similar in appearance. Depending on the conditions a plant is growing under, the size of the plant, leaves and flowers can range from very large to very small – which has led to many “new species” being described that are later found to be simply variations that developed in different locations due to the conditions.

The greatest diversity of species occurs in Central America and Mexico, these plants were used culturally both in the New World and in Asia as sacred plants for many millennia (at least 3,000 years). All Datura plants contain a number of alkaloids, especially in the seeds and flowers, that are toxic, narcotic and hallucinogenic. The toxicity depends on the age of the plant and growing conditions, with serious illness or death a possibility from ingestion.
D. inoxia has a more upright habit with a regular branching pattern and can get up to 5 feet tall. The gray-green to dark green alternate leaves up to 10 inches long and 4 inches wide have a lobed or toothed margin. The coarse-textured foliage is foul smelling when handled and the sap can cause a skin rash in sensitive individuals.

Datura plants are shrubby and spreading with leaves that vary in color from medium green to gray-green and with entire to lobed or toothed margins.
The flowers exude a pleasant honeysuckle-like scent, especially at night, which attracts night-flying sphinx moths which are their primary pollinators. The flowers may also be visited by honey bees and other insects. Plants bloom continuously from summer until frost.

Flowers are followed by rounded fruits that are walnut-sized capsules with sharp and spiky spines at maturity. The capsules split open when ripe to release the numerous flattened tan or brown seeds that are similar in appearance to stout tomato seeds. Unless the seed capsules are removed before maturity, the plants tend to self-seed and can become invasive. Seeds remain viable for years.

The large, coarse foliage of datura contrasts well with many other plants with fine or medium texture.
Daturas tend to be large, sprawling plants with a coarse texture, so they are best suited as specimen or background plants in mixed or annual plantings. If possible, place them where the fragrance of the dramatic flowers may be enjoyed. Those with white flowers are a natural choice for the moon garden as they are most fragrant in the evening. The bold foliage contrasts well with short ornamental grasses and annuals with fine or medium foliage and lots of flowers.

Grow datura in full sun and well-drained soil (it will grow in partial shade, but will be leggier and have fewer flowers). It is drought tolerant once established and thrives in almost any type of soil, but the plants are most impressive when grown in humus-rich loam with regular moisture.

Datura grows quickly and needs plenty of room.
They need plenty of room and will quickly grow to fill an area of several feet once the weather gets hot so place them accordingly. They may be grow from seed sown outdoors after the last frost or started indoors 6-8 weeks before the average date of last frost and planted outdoors after all threat of frost has passed (and after acclimating the young plants to outdoor conditions).

Datura grows quickly from seed, often in dense groups when self-sown, producing narrow cotyledons and then rounded leaves.
Although they can be grown in large containers, they are generally best grown in the ground because of their size. They rarely need pruning, although stems can be cut back to shape the plants. Staking may be necessary for some plants. They have almost no pest problems, but may be infested with whiteflies, mealybugs and spider mites.

© Susan Mahr, University of Wisconsin – Madison