Vitex-TheTexas Lilac (Vitex agnus-castus)

It has now been a whole month since I finished my horticulture degree at A&M.  In that time I have had three people approach me to do landscapes for them (it is interesting to me that people think all horticulturists are landscapers).  One horseman wants me to landscape his two entry gates, my family cemetery wants me to landscape their entrance and another person wants an “LSU Garden” in their yard.  While all three of these projects are very different, all three will feature a very lovely and durable plant – Vitex (Vitex agnus-castus).

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The 12″ flower spike of the Vitex are beautiful and irresistible to butterflies and hummingbirds

Vitex is a small flowering tree that is, in my opinion, one of the best ornamental trees you can own. Its long, curvy, purple-blue flower spikes have earned the vitex the nickname of “The Texas Lilac”.    In addition to its beautiful flower spikes, this little tree can take the heat, endure the drought and is resistant to most pests.  It attracts butterflies and hummingbirds and deer do not like it.  With all it has going for it, this drought resistant tree really is a perfect choice for the Texas homeowner.

Vitex are typically grown as a multi trunked tree.  The multi-trunk look is achieved through pruning.  When grown as a tree they  grow to about 15 feet.  However, some varieties can get as tall as 35 feet.   If left alone from seed, the Vitex will grow into a lovely shrub that makes a stunning hedge that can, with regular deadheading, produce those long, lovely flower spikes throughout the summer.

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My Hyperion daylilies pair nicely with a Vitex I have left in a shrub form

You can find Vitex with pink flowers, mauve flowers and white flowers.  However, most of the Vitex sold in the trade have a purple-blue colored flower that is often called lilac.  The three most common varieties sold here in Texas include Shoal Creek, Montrose and Le Compte.  My friends at Tree Town USA are about to release a new, and as of yet unnamed, dark blue flowering variety.  Look for them this fall at all of the major nurseries or your local big box.

If you want to grow your own Vitex, plant it in the fall.  Like most trees, the cooler weather of fall will allow the plant to establish itself with much less water.  You can also plant it in the winter when it is dormant.  If you miss both of those opportunities you can still plant it in early spring.  Just remember though, the longer you wait, the more effort and water it will take to fully root.

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Since all of these lovely little flowers produce seeds, Vitex can be a bit invasive

While I do love this tree, it does have a couple of small problems.  First, each of those little flowers on those 12” flower stalks will produce a little seed.  Because of this it can be a bit invasive.  This is not a huge problem for the homeowner.  The weed eater and mower can easily control all of the volunteers that sprout in the yard.  However, if planted near a creek or tank, the plant can easily escape and create enough of a problem that it is currently listed as an invasive species on the Texas Invasives website (http://www.texasinvasives.org/plant_database/detail.php?symbol=VIAG).  You can control the spread of this plant by diligently deadheading each spent flower spike before the seeds develop.   The other little problem is allergies.  If you have a sensitivity to tree pollen you may want to avoid this tree.  All of those flowers produce pollen and many people claim to be allergic to it.

vitex-flowers-4As I drive around I notice more and more Vitex in yards, commercial landscapes and along the roads and highways of our great state.  I think this is great.  Vitex is a beautiful and versatile plant that blooms throughout the summer and thrives on average annual rainfall.  It is no wonder that the Texas Highway Department has added them to their list of preferred plants.  If this plant thrives along the hot and dry roadsides and medians of our great state, imagine how well it will perform for you in your yard!

11 thoughts on “Vitex-TheTexas Lilac (Vitex agnus-castus)

  1. I love using Vitex in designs. They make a good focal plant and a good background small tree. I have not had any problem with seedlings but that might be because we have lots of birds that love to eat the seeds.

    • I have not had much of a problem with volunteers either. However, I had never thought that it might be the birds eating the seeds that were keeping the volunteers away! I was actually beginning to think i had some sort of sterile variety. Thanks for the comment!

    • You are correct on both of your observations. Birds do spread lots of seeds. All you have to do is look at all of the hackberry trees growing along fence rows. Also, the Texas Invasives website is a great place to check before planting something you don’t know about! Thanks for the comment!

  2. I’m glad you mentioned this tree as a potential allergen. Many articles neglect to include allergen information, seemingly because they don’t adequately research plants written about.

    Last fall I purchased two vitex. Having only smelled them and loaded them into the shopping cart and pickup, upon arriving home I soon realized the minor itching I had while driving home was due to handling the vitex. Not wanting to worry about contact dermatitis whenever pruning would be needed, they were immediately returned.

    • As someone that suffers from several allergies, I am always very careful when recommending plants that produce lots of pollen. Thanks for the comment.

  3. My Vitex is hardy but rangy. I have pruned it back once about 30-40% of its growth the first year to encourage bushing (it is 2 years old), but it came back more rangy that before. Any suggestions are appreciated….

    • First, is it in full sun? Some that are in partial shade have a tendency to get leggy. If it is getting enough sun you have two options. One, give it more time. It may grow more branches on the existing branches. Second, wait until it drops all of its leaves in winter and then cut all limbs to within 6″ of the ground. If you do this, there is a bout a 75% chance or greater it will come back. If it does come back it should be nice and bushy.

  4. I’ve purchased a few vitex and I want to plant near a fence. How far from the fence should I go? I want to prune them as trees and not shrubs. Thank you.

    • I have three planted about 18″ inches away from a fence. That has proven ok. The problem is I planted two of them on either side of a 5′ walkway. That 18″ was too close. Even though I trim them into a tree form, the canopy gets in the way. In fact, I was carrying 50 lbs of chicken feed this weekend and walked right into a huge spiderweb that had been built in one. So, I would say consider the canopy size when planting. The roots are not invasive so that is a problem. However, realize the canopy will be 6′ to 10′ wide in just a couple of years so I would use that as a guide to determine how far away from the fence to plant them.

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