How to Grow and Care for Chaste Tree

Chaste tree, also commonly called chasteberry, vitex, or lilac chastetree, is a shrub or small tree that bears clusters of purple flowers in the summer. This plant prefers warm temperatures and needs full sunlight to thrive, though it tolerates most soils. Many cultivars of chaste tree are available, offering a range of bloom colors.

Chaste Tree Care

This is an easy-to-grow shrub that poses few challenges to a home gardener. If you avoid soil that is too wet or dense, success is nearly guaranteed. Here are the main care requirements to grow chaste tree:

• Choose a sunny spot that ideally gets at least six hours of direct sunlight.
• Prepare well-draining soil.
• Water the chaste tree initially, but once it's established, water isn't needed outside of prolonged drought.
• Fertilize ever other year or so in the spring.

Warning

Chaste tree is considered to have invasive tendencies in some southern states such as Texas, where it has been used extensively for landscaping, gradually naturalizing into surrounding areas.

Light

Chaste tree will grow well in full sun to part shade, though the best flowering occurs in full sun.

Soil

Choose a location where the water drains away instead of gathering. This shrub can handle most soil types, as long as the soil doesn't hold too much moisture. Native to Mediterranean regions, this plant prefers relatively dry soil. Sandy or rocky soils are no problem.

Water

In most regions, you will not need to water a Vitex at all once it is established. In fact, you should avoid using organic mulches, since they can hold a lot of water.

Temperature and Humidity

Vitex agnus-castus may be grown in zones 6 to 9; it is technically hardy down to about -9 degrees. But in zones 6, it often is grown more as a perennial plant rather than a shrub, where it often dies back to the ground each winter, regrowing in spring. It does equally well in the high humidity of the southeastern United States as in the arid climate of the Southwest.

Fertilizer

A chaste tree doesn't require much, if any, feeding. At most, a single application of a general-purpose balanced fertilizer every year or two will suffice. For the amount to use, follow product label instructions.

Types of Chaste Tree

Several cultivars of chaste tree are widely sold:

• V. agnus-castus ‘Abbeville Blue’: grows 6 feet tall with a similar spread; it has deep blue flowers on 12- to 18-inch spikes.
• V. agnus-castus 'Alba': white flowers; it is a large plant, growing to 15 feet with a 20-foot spread.
• V. agnus-castus 'Shoal Creek': a 15-foot-tall plant with purple-blue flowers and leaves that have good resistance to fungal spots.
• V. agnus-castus 'Blue Puffball': a great small shrub, growing only 3 feet tall with delicate blue flowers.
• V. agnus-castus 'Rosa Ann': a 15-foot plant with heavily scented pink flowers.
• V. agnus-castus 'Rosea': another pink-flowered cultivar, growing to 15 feet.

Pruning

Left unpruned, chaste tree can become a sprawling, vase-shaped shrub that sometimes grows to 20 feet or more with a spread equally as wide. It is sometimes trained as a single-trunk small tree by pruning away competing shoots to encourage a central leader.

Early pruning during winter will help keep the shrub in an attractive shape and control its size. Chaste tree tolerates heavy pruning quite well.

You can encourage continued production by deadheading, or removing, spent flowers—a task that can be a little irksome with larger shrubs. Aggressive deadheading often produces a second flush of flowers about six weeks after the first.

In colder climates, this plant is often pruned down to the ground just before winter. Because it flowers on new wood, your chaste tree will return to a 3- to 5-foot flowering shrub each year, even with this fierce pruning routine.

Propagating Chaste Tree

The easiest way to propagate a chaste tree is by rooting some branch cuttings. As you might expect with such an easy-to-grow plant, chaste tree roots quite easily:

1. In early summer, clip off a 12- to 18-inch branch tip using sharp pruners, then cut off the flowering end portion. Remove the leaves from the bottom half of the cutting.
2. Put the cutting into a vase of water, and set it in a location that receives morning sun but afternoon shade.
3. Over two months or so, the existing leaves will fall off the cuttings, but the other growth nodes will begin to bud and send out green growth.
4. When the bottom of the cutting also begins to develop hairlike roots, the cutting can be transplanted into a pot or to a garden location.

How to Grow Chaste Tree from Seed

The seeds found within the fruits will readily sprout up wherever they fall in the garden, and these volunteers can easily be transplanted into new locations. Or you can collect the seeds and plant them yourself:

1. Collect the fallen fruits and extract the seeds.
2. Choose a new sunny spot to plant, or prepare a temporary pot with well-draining soil.
3. Sow the seed about 1/8 inch deep.
4. Water initially and then leave the seed alone.
5. A winter outdoors may be required for germination, so consider attempting in fall.
6. If growing in a pot, transplant into a permanent location after germination.

Potting and Repotting Chaste Tree

Growing a smaller cultivar of chaste tree in a pot is easy. Smaller cultivars grow only 3 to 6 feet. You can keep the tree in the same pot for a few years before any repotting is necessary. Follow these simple steps:

1. Measure the root ball of the tree, then choose a container that is at least 8 inches larger in diameter than the root ball. The planter should have several drainage holes.
2. Line the planter with landscape fabric to prevent dirt from coming out of the holes.
3. Blend a good quality, well-draining potting mix with about 10 percent perlite, then pot up the plant.

Overwintering

In the landscape, chaste tree usually requires no winter protection if grown in its recognized hardiness range.

In zone 6 (and sometimes even zone 5), some gardeners grow chaste tree as a perennial plant, cutting it back to ground level each winter and allowing it to sprout back each spring. It generally will put on 3 or 4 feet of growth and reach flowering maturity each season.

Common Pests & Plant Diseases

Usually, the only problems you see on chaste tree are root rot, nematodes, and leaf spot, though these are not common. Problems usually occur when the soil is not dry enough.

Aphids, whiteflies, and scale insects may also attack, but they are usually easily controlled with horticultural soaps and oils.

This plant needs well-draining soil, and if grown in soggy conditions, it may experience fatal root rot.

How to Get Chaste Tree to Bloom

A happy chaste tree will bloom without issue, adding color and fragrance to your yard.

Bloom Months

Chaste tree normally has a long bloom season that can begin in early summer and continue into September.

What Do Chaste Tree Flowers Look and Smell Like?

Chaste tree flowers are often confused for lilacs, based on both their color and shape. The small, purple flowers form along half-foot spikes. However, the flowers do not smell like lilacs, instead emitting a spicy, peppery fragrance.

How to Encourage More Blooms

If your chaste tree fails to bloom as robustly as you expect, it's likely because the plant is not getting enough sunlight. Another hindrance is excessive fertilizer. In most soils, this plant will require no additional feeding; fertilizer sometimes reduces flowering by stimulating green growth at the expense of blossoms.

Caring for Chaste Tree After It Blooms

No particularly different care is needed for chaste trees after they bloom. Continue caring for it as you have been, though you may want to deadhead flowers throughout the blooming season.

Deadheading Chaste Tree Flowers

Deadheading chaste tree flowers is a great idea, as peak bloom periods will repeat themselves if the spent flowers are removed.

Common Problems With Chaste Tree

This is a remarkably easy plant to grow, but some homeowners become annoyed with its messiness.

The summer fruits can stain pavement or lawn furniture, and the prolific self-seeding requires constant plucking of volunteer plants to keep them from spreading. In fact, some gardeners eventually remove the plant altogether due to this aggressive behavior.

From: thespruce