Chaste trees, also known as Vitex, are stunning, low-maintenance, summer-blooming shrubby trees that attract pollinators. They grow quickly and produce dense, upright flower spikes, which sometimes reach up to 12 inches long from late spring to fall. Their flowers are mostly violet-blue but can also be purple, pink, or white. Both the flowers and leaves carry a unique spicy fragrance.
Types of Chaste Tree
Several popular chaste tree cultivars are available, each with unique characteristics:
Abbeville Blue – Reaches 6 feet tall with a similar spread, featuring deep blue flowers on impressive 12- to 18-inch spikes.
Alba – A large variety growing up to 15 feet tall and 20 feet wide, producing elegant white flowers.
Shoal Creek – Grows to 15 feet tall with purple-blue blooms and excellent resistance to fungal spots.
Blue Puffball – A compact shrub, only 3 feet tall, covered in delicate blue flowers.
Rosa Ann – A 15-foot variety with heavily scented pink flowers.
How to Grow Chaste Tree From Seed
You can collect or purchase chaste tree seeds from dried fruits from a garden center. Since seedlings often sprout naturally from fallen fruit, remove them to prevent unwanted spreading.
Extract the seeds and press them into moist potting soil to grow from seed. Place the container or seed tray in direct sunlight. Chaste tree seeds need full sun and consistently moist soil to germinate. With proper care, seedlings will emerge in about two weeks.
Once they reach a few inches tall and frost has passed, transplant them into the ground. If you are starting seeds indoors, begin about a month before the last expected frost.
Potting and Repotting Chaste Trees
If your chaste tree outgrows its container, repotting will give the roots more room to spread. Select a pot eight inches wider than the root ball, allowing for two to three years of growth before the subsequent transplant. Make sure the container has enough drainage holes to avoid waterlogging. Use a well-draining potting mix blended with perlite to promote healthy root development.
Pruning
If you don’t prune your chaste tree, it can develop into a sprawling, vase-shaped shrub, sometimes reaching over 20 feet tall and wide. However, it can also be trained as a small tree by pruning away competing shoots to establish a single trunk.
Winter pruning helps maintain an attractive shape and manage size, as chaste trees tolerate heavy pruning well. Deadhead spent flowers to encourage continuous blooming, though this can be tedious for larger shrubs. Regular deadheading often leads to a second bloom about six weeks after the first.
Chaste trees are often cut back to the ground before winter in colder climates. Since they flower on new wood, they will reliably regrow into a 3- to 5-foot shrub each year, even with aggressive pruning.
How To Care For Chaste Tree
Chaste trees are a striking addition to any landscape. Use them as a single specimen on a lawn, line them along a driveway or property border, or grow them as patio trees with smaller plants beneath. They’re easy to grow but require regular pruning to prevent them from becoming invasive.
These trees thrive in full sun. In colder areas, they may die back to the ground in winter but will regrow and bloom the following summer. Chaste trees are a magnet for pollinators, especially bumblebees, which often linger on the flowers overnight.
Light
Chaste trees thrive in full sun, requiring at least six hours of direct sunlight daily. While they can tolerate partial shade, they won’t produce as many blooms in lower light conditions.
Soil
Chaste trees prefer slightly acidic to neutral, well-draining soil. They thrive in dry, nutrient-poor conditions rather than overly rich or moist environments. They are highly adaptable and grow well in sandy or rocky regions. Once established, they become drought-tolerant.
Water
Water deeply when first establishing a chaste tree to help the roots take hold. Once mature, it becomes highly drought-tolerant and rarely needs additional watering. Avoid using organic mulch or overly rich soil, as excess moisture retention can lead to root issues.
Temperature and Humidity
Chaste trees handle high heat well and withstand temperatures as low as -9°F. They thrive in arid climates, with humidity rarely posing a problem. Strong winds aren’t a significant concern.
Fertilizer
Avoid using organic material, as it holds too much moisture. Applying a slow-release, general-purpose fertilizer every year or two helps maintain a healthy shrub. Don’t over-fertilize, as it can cause excessive foliage growth.
Common Pests & Plant Diseases
Chaste trees are generally pest-resistant, but occasional infestations of thrips, aphids, whiteflies, or scales can occur. To control them, spray the tree with a hose in the morning or use insecticidal soap. Avoid leaving foliage wet, as excess moisture can lead to fungal issues like root rot and leaf spots.
