Angel's Trumpet (Brugmansia)

Athena writes~ My tree [angel trumpet tree (brug.)] is in a pot where it gets only a few hours of sun each morning. It produces flowers, but lately the leaves have been turning slightly yellow. Does it need a larger pot or more sun?

A. Angel's trumpet, Brugmansia, features blooms dangling like great trumpets or bells from the large shrubs and range from 7 to 14 inches long, depending on the species. Brugmansia may be grown in containers or in the garden, in a fertile, moist, but well-drained soil. Grow in full or part sun. The plant may grow as tall as 15 feet, especially following a mild winter.

I suspect that your plant may need on or both of these:
more sunlight, as 2-3 hours is insufficient
more nitrogen, as the yellowing foliage could be deficient in this necessary element.

The flowers begin to appear in spring, continue in fewer numbers in the summer, but pick up again in the cooler fall months. Apply a balanced [20-20-20 is good] fertilizer monthly during the growing season. Plants should be heavily mulched for the winter. Plant tops will freeze, but new growth from the roots usually appears each spring.

Container-grown plants moved indoors for the winter may bloom during those months. You can propagate brugmansia from cuttings. Take 5-inch-long cuttings from half-ripened wood in the fall, and root in a good potting soil. Eight to 10 cuttings fit nicely in a gallon pot.

Use a balanced, slow-release fertilizer but use a high-phosphorus fertilizer on those plants that are reluctant bloomers. Use a high-nitrogen fertilizer to green up your yellowing plant.

Assistance from the Houston Chronicle

Angel's Trumpet (Datura)

Q. Please can you give me any information on Angel's Trumpet, especially how and when to take cuttings and also whether or not they can be put outside.

A. Angel's trumpet [Datura, probably Brugmansia] is a tropical plant, so cannot take any frost. I do not know where you live, but since you are asking whether they can be put out, I would say, yes, during the spring after your frost date and then removed to the indoors in the fall. They need a hot to warm climate, sunny sheltered site with well-drained, light, fertile soil.

They demand a lot of water and bloom readily in yellow, white or apricot-pink, as fragrant pendent trumpets.

The method of propagation is by seed. Harvest it, allow to dry well and undisturbed, nick the outer shell, soak overnight in water and sow in a flat or tray. When hardy and strong, transplant to a large pot or garden bed.

You could try taking cuttings of 6-8" long, remove the lower leaves, stick 2" deep into moist vermiculite and perlite. Keep shaded until they show signs of growth. I have not done this method, but if you take young, healthy growth, in June or July, you may have success.

Mara writes~
I have an angel's trumpet tree. It has a lot of yellow leaves. It does get flowers, but they only last a few days. You mentioned in an answer to "Athenia" about an angel's trumpet...use a slow released fertilizer, but a high phosphorus fertilizer and a high nitrogen fertilizer to green up yellow plant. What brands, and what proportions. I live in Boca Raton, Florida.

There are so many high Nitrogen fertilizers available. It is best to check the products at your local nursery or garden center. Read the label and ask the assistants for advice. It will be lower priced than buying online since you avoid the shipping and handling charges. Some well-known ones are:

Plantex 28-14-14 High Nitrogen Fertilizer or 24-8-16 Foliage Fertilizer, Liquid Fenc SPEEDY-GRO, AGGRAND 4-3-3 Liquid Natural Organic Fertilizer (less desirable since the concentration will need to be increased), Rapid-Gro, Miracle-Gro. Look for a high first number in the set of three. These are used to green up the plants, shrubs and vines. To increase flowering after the foliage is green, consider using biweekly 15-30-15 High Phosphate fertilizer.