How to Grow & Care for Angel's Trumpet (Pricklyburr)

Angel's trumpet (Datura inoxia) also goes by the common name of pricklyburr and is a perennial flower native to warm climates. In cooler climates, it's often grown as an annual. The plant has a small, shrub-like appearance, growing wider than it is tall. It features dark green, oval leaves that can reach up to 8 inches long and have a soft texture. It blooms sporadically with fragrant, upward-facing, 7-inch trumpet-shaped flowers in the summer and fall.

It is not to be confused with a plant of a different genus, Brugmansia, also called angel's trumpet, which looks very similar and is also in the same Solanaceae nightshade family. You should plant angel's trumpet in the spring after the danger of frost has passed and the ground has warmed. The plant has a relatively rapid growth rate. It is invasive in California and other parts of the world. All parts of the plant are toxic to people and animals.

Angel's Trumpet Care

Angel’s trumpet plants are fairly easy to care for. You can purchase nursery plants in the spring or start seeds indoors roughly seven weeks before your area’s projected last frost date.

Transplant young plants into the garden once spring temperatures are reliably warm. Select a planting site that gets a lot of sunlight to promote healthy growth. Space your plants a few feet apart to account for their mature size; crowded angel’s trumpets often produce fewer blooms.

Light

Angel’s trumpet grows best in full sun, meaning at least six hours of direct sunlight on most days. It can grow in partial shade, but this often will cause the plant to be leggier and produce fewer flowers. 

Soil

The plant can survive in a variety of soil types. But it prefers rich, loamy soil with sharp drainage. A neutral or slightly alkaline soil pH is best, and it can even tolerate very alkaline soil. For container plants, a loose all-purpose potting mix is generally acceptable.

Water

This flower has moderate moisture needs. During its first growing season, water daily to keep the soil evenly moist but not soggy. Standing water can lead to root rot. Mature plants have some drought tolerance but still prefer a weekly watering during spells without rainfall and during the warmest parts of the year.

Reduce watering in the winter; only water to prevent the ground from completely drying out. In the heat of summer, give it water every morning. Also, water it whenever the soil has dried out about an inch down.

Temperature and Humidity

Angel’s trumpet prefers warm temperatures. It has good heat tolerance as long as its moisture needs are met. But it’s not very cold hardy; frost and freezing temperatures can damage or kill it. Ideally, it should be kept in temperatures above 50 degrees Fahrenheit. Humidity typically isn’t an issue for the plant with proper watering.

Fertilizer

If you have rich soil, supplemental fertilization might not be necessary. But if you need to give your plant a boost, feed it in the spring with a high-nitrogen fertilizer made for flowering plants, following label instructions. Compost mixed into the soil in the spring can also be beneficial.

Follow up 4 to 6 weeks later with high-phosphorus fertilizer (NPK 5-10-5) to promote flowering. Liquid fertilizer is better than granular types since it’s easier to apply and can be diluted to prevent plant burn.

Types of Angel's Trumpet

Several Datura species also use the common name of angel’s trumpet, including: 

• Datura metel: This species is slightly more cold-tolerant than Datura inoxia but otherwise is very similar to the plant.
• Datura ferox: Also known as the long-spined thorn apple, this species sports intimidatingly large spines on its seed pods. 
• Datura stramonium: Commonly called thorn apple or jimson weed (also jimsonweed), this plant is notable for its small, prickly seed capsules, too,as well as its trumpet-shaped flowers.

Pruning

Pruning typically isn’t necessary, but you can lightly trim the plant at any point during the growing season to keep its shape neat and growth in check. Prune off dead, damaged, or diseased stems.

Propagating Angel's Trumpet

Angel's trumpet can be propagated by dividing the root, taking stem cuttings, or planting seeds. The easiest method is sowing seeds. It's a good idea to divide the plant after about three or four years before it starts to fade and its natural life cycle ends. Also, since this plant is an annual in many parts of the U.S., you can take stem or root cuttings at the end of the growing season to keep it alive for the next growing season.

To propagate via division (or root cutting):

1. You'll need a hand shovel or trowel to dig around and lift out the root ball.
2. Due to the toxicity of all parts of this plant, wear gloves during the entire process.
3. Using a sharp sterilized knife, and depending on how large it is, cut the tuberous root ball in half, thirds, or quarters on top of a flat, hard surface.
4. Transplant the root portion into a pot with drainage holes. You should fill the pot with rich, loamy soil. Make space for the root portion. If the root portion has foliage, plant it according to the natural soil line as if transplanting it to another pot. If it has no leaves, plant it about an inch deep.
5. Keep the soil moist but not soggy. Keep it warm and in a bright window until you notice growth; it can take weeks or months, depending on how warm the plant remains. Once the temperature remains steadily above 50 F outside, transplant it outdoors for the next growing season after hardening or gradually acclimating it to outdoor life.

To propagate via stem cutting:

1. You'll need gloves, sterilized scissors or hand pruners, a planting pot, and optionally, rooting hormone. The rooting hormone can help the cut-end of the stem to form roots.
2. Select a healthy 4- to 8-inch stem with leaves on it. It doesn't matter where you cut it.
3. Remove the lower leaves and keep only one or two pairs on top.
4. Optionally, dip the cut stem end in rooting hormone.
5. Plant the cut end about 1 to 2 inches deep in loamy soil or specialized cutting soil mix. Keep the soil moist, and place it in a warm window with bright but indirect light. If the windowsill is too dry, you can wrap the cutting in plastic to give it a greenhouse environment with constant ambient moisture to promote its rooting.
6. Once you notice growth (time varies based on how much warmth it gets), and the temperatures warm outdoors, harden it or gradually acclimate it to outdoor life.

How to Grow Angel's Trumpet From Seed

Angel's trumpet is easy to grow from seed. You can grow angel's trumpets inside or outside in a pot or simply spread seed on a soil bed in a sunny location.

1. Soak the seeds for 24 hours in warm or room temperature water.
2. Select a pot with drainage holes and fill it with potting mix. Press the soaked seed into the top of the soil. Do not cover it since it needs light to germinate.
   
3. Water the soil and always keep it moist but not soggy. Make sure the soil remains warm by keeping it in a warm spot, on a warming mat, or under a heat lamp.
4. It can take three to four weeks to germinate.
5. Seedlings will need about 18 hours of light a day, so place the seedling in a south- or west-facing window and supplement with six to eight hours under a grow light.
6. Once the plants have grown for six to eight weeks indoors and the temperatures have warmed up outdoors to temperatures over 50 F, acclimate or harden them: Expose plants to the outdoors for a few hours each day, gradually increasing their outside time over two weeks.
7. After hardening, transplant them outdoors to a sunny location.

Potting and Repotting Angel's Trumpet

Although they can be grown in large containers, angel's trumpets are generally best grown in the ground because of their size. Staking may be necessary for some plants. 

Overwintering

Frost outdoors for more than a day or so will kill angel's trumpet. Bring in angel's trumpet during the winter if growing it outside its USDA hardiness zone. If raising it outdoors on the edge of its growing zone, protect it during the cooler months by wrapping it in hay, burlap, or bubble wrap.

If temperatures get colder than 40 F, cut the plant down to one foot above the soil line. Dig it out from the ground, pot it, and water it once a month. Keep it at about 50 F to 60 F. It doesn't need much light. The remaining leaves will drop, but the plant should rebound once replanted outdoors in the spring.

Common Pests & Plant Diseases

Angel's trumpet usually doesn't have any significant issues with pests or diseases since it's a toxic species. However, slugs are immune to the plant's toxicity. If you spot slugs, pry them off. This plant may still get some common plant visitors, like whiteflies, mealybugs, and spider mites. Treat these issues with a natural or organic remedy as soon as you spot them. You shouldn't need any chemical insecticides.

Datura inoxia is not susceptible to plant diseases, but like any other plant, it can get root rot if it sits in soggy water. If the soil looks overly moist with yellowing leaves, it might be developing root rot. Allow the soil to dry out before watering. Check that a potted plant has ample drainage holes and consider mixing sand in its soil to improve drainage.

How to Get Angel's Trumpet to Bloom

Angel's trumpet flowers have a sweet, honeysuckle-like smell most noticeable at night. Angel's trumpets need ample sunlight to bloom. Ensure that the plant is getting at least six hours of direct sunlight. Feed it weekly with phosphorus-rich fertilizer to encourage flowering if your angel's trumpet is not blooming. For the amount to use, follow the product label instructions.

There is no need to deadhead or remove spent blooms from your angel's trumpet plant, but you can if you wish to keep the plant looking tidy and prevent it from self-seeding. Deadheading may also help stretch out the plant's overall blooming period.

Common Problems With Angel's Trumpet

Irregular or Fading Growth

Datura inoxia's natural life cycle begins to wane after three to four years, signifying that you should divide your plant. You may also notice yellowing foliage and a lack of blooms.

Yellowing, Wilting Leaves and Flower Droop

Interestingly, a plant getting too much water or not enough water reacts the same way; its leaves begin to yellow, curl, and wilt and its flowers may start drooping or falling out. Hold off watering until the soil dries out if it is wet. Conversely, if the soil is too dry, water it regularly with more frequency and more volume.

Stunted Growth or Blotches on Leaves

If you notice your plant has mottling, streaks, or blotches in a mosaic pattern on its leaves and its growth has stopped, though rare, it might be a mosaic virus. This disease is more common in other plants in the nightshade family, such as tobacco or tomatoes. It's spread by aphids that pass it to other plants, commonly in greenhouse situations. If it's a mosaic virus, the plant will need to be destroyed. Do not compost it.