How to Grow Texas Mountain Laurel

Dermatophyllum secundiflorum

The intoxicating fragrance of Texas mountain laurel is enough to cause drivers to slam on the brakes or dog walkers to abruptly stop short, giving poor Fido whiplash.

A close up vertical picture of the purple flowers of the Texas mountain laurel shrub with a black butterfly on the flowers in bright sunshine on a soft focus background. To the center and bottom of the frame is green and white text.

Famed TV chef Emeril Lagasse used to lament the non-invention of “smell-o-vision.” I wish for “smell-o-website” so I could share with you the heavenly scent produced by the pretty purple flowers of these shrubs.

Even better, this is one of those plants that disperses its aroma several feet; I can smell my neighbors’ plant’s blooms from across the street.

Some compare the scent to grape Kool-Aid, soda, or gum, but the fragrance is deeper, richer, and more floral than the artificial aroma of processed food.

Read on to learn more!

What Is Texas Mountain Laurel?

Texas mountain laurel’s glossy, dark green leaves are evergreen and leathery. The large clusters – as long as 6 inches – of showy flowers appear in early spring, and sadly, bloom for just a few weeks before withering and taking their scent away.

A close up of the bright purple flowers of the Dermatophyllum secundiflorum shrub, the blooms contrasting with the dark green leaves in light sunshine.

Though these slow-growing plants can be kept pruned to a shrub size, most often they are allowed to mature into small treelike forms 10 feet wide and 15 feet high, multi- or single-trunked.

Older specimens in their natural habitat can reach 30 to 50 feet tall at maturity.

But the breathtaking bouquet is just one of the charms of this Texas native, which is hardy to USDA Hardiness Zone 7b.

This plant has several common-name aliases, including coral bean, hot bean, mescal bean, mescal bean sophora, frigolito, frijollito, frijolillo, coral bean, big-drunk bean, and colorin.

Some of these are reflective of the plant’s native territory, which in addition to central, southern, and western Texas, also includes New Mexico and northern Mexico.

A vertical picture of a Texas mountain laurel shrub growing up the side of a building in bright sunshine. In the background is a large white building with a dome roof in soft focus with blue sky.

But, Texas being Texas, we had to stamp it with our own name, of course.

Previously known interchangeably as Sophora secundiflora and Calia secundiflora, recent phylogenetic studies have led to the reclassification of certain members of the Sophora genus into Dermatophyllum – a taxonomic synonym for Calia.

You will still see Texas mountain laurel referred to as S. secundiflora or C. secundiflora in some places.

Lovely as they are, the flowers of Texas mountain laurel are toxic to humans and animals, as are the plant’s seed pods and leaves. The seeds – called mescal beans – are a pretty orange-red color and are sometimes used as necklace beads.

Cultivation and History

A quick note: those of us here in Texas understand there’s another plant that calls itself “mountain laurel.” Nevertheless, our laurel is unrelated to Kalmia latifolia, a member of the heather family, Ericaceae, whereas ours is in the pea family, Fabaceae.

A close up of the pink and white flowers of the Kalmia latifolia bush on a soft focus background.
Kalmia latifolia, a member of the heather family is also called “mountain laurel.”

Toxic mescal beans were used ritually by indigenous peoples of the Central and Southern plains tribes for their psychoactive properties. Evidence of their use can be found in numerous archaeological sites in Texas and Mexico, and shows that these cultures also used the colorful seeds decoratively.

The mescal beans contain a number of poisonous quinolizidine alkaloids, including cystine, a narcotic alkaloid with a similar molecular structure to that of nicotine.

However, in spite of the name, they do not contain the hallucinogenic alkaloid mescaline, found in the peyote cactus. Nor should they be confused with the alcoholic beverage mezcal, which is made from the agave plant.

Propagation

These plants grow slowly, so if you’re looking for an immediate statement in the landscape, you might consider purchasing a well-established specimen in a large container from a local nursery.

A close up of a purple flower of the Texas mountain laurel shrub with green foliage surrounding it on a soft focus green background.

Texas mountain laurel does not propagate well from cuttings.

However, if you’re patient, you can grow a Texas mountain laurel from seed.

From Seed

Seeds that fall from the plant can take years to germinate, as they have extremely hard shells. But a few tricks may provide faster results, if you’d like to grow some seedlings for transplant into the garden.

A close up of a dried seed pod of the Texas mountain laurel plant, cracked open showing the bright red seeds within, on a soft focus background.

If you’re collecting seeds, pick the pods when they’re still mostly green but just starting to turn gray. The seeds will be pale pink and their shells will be relatively soft.

Sow these in gallon-sized containers with holes in the bottom filled with well-draining potting mix. Water often.

Alternatively, you can direct sow in the garden. Bury the seed about 1/2 inch deep.

And be patient.

If someone hands you some hard, older pods, soak them in water to make it easier to break them apart and get at the seeds. With both donated and purchased seeds, chances are they’re more mature. You’ll have to scarify them before planting, as they have extremely hard shells.

As you would with morning glories, scratch them up with a knife, for example, or use sandpaper.

A close up of the hard seed pods of the Texas mountain laurel bush surrounded by foliage in bright sunshine with the blue sky in soft focus in the background.

You can try soaking the seeds in warm water for 2-3 days, changing the water regularly to keep it tepid. This approach appears to work best if you first make a small cut in the tough outer shell.

However you plant your seeds, water them daily for the first couple of months, then about once a week for another year.

From Seedlings or Transplants

When transplanting into the ground, mix some extra calcium into the soil at the planting site to help plants get established.

Dig a hole slightly bigger than the root ball, then carefully place the root ball into the hole, and backfill with planting site soil.

Mature Texas mountain laurels have a deep root system, and they do not transplant well once established.

How to Grow

Texas mountain laurel prefers alkaline, well-drained rocky soils, including those that contain limestone. They’ll do well in clay, loam, and sand, and will tolerate being planted in or near turf.

A Texas mountain laurel shrub growing in the garden with bright purple flowers contrasting with the green foliage in light sunshine on a soft focus background.

Choose a planting site in an area that gets full sun. D. secundiflorum will also tolerate light shade for part of the day.

Once established, these drought-tolerant shrubs require little to no irrigation.

They also do perfectly well with no fertilization, but in areas with very poor soil you can add a small amount of a balanced fertilizer such as NPK 10-10-10 in springtime.

Growing Tips

  • Plant in a sunny spot
  • Soil should be alkaline and well-draining
  • Water regularly for the first year

Pruning

There is no actual need to prune Texas mountain laurel. But if you want to change its form, say, into more of a traditional tree shape, or into a more compact bush, you can do so.

A vertical close up picture of a Dermatophyllum secundiflorum shrub with light purple flowers contrasting with the bright green surrounding foliage.

Keep in mind that the blossoms only appear on year-old wood. So while you might be tempted to prune during winter dormancy, this might result in less abundant blooms.

An alternative pruning time is in the summer, after it has finished flowering. When the brutal heat strikes, like many of us, these plants will go dormant.

Prune no more than one-third of the plant at a time. First prune out any deadwood. Then cut out thin, spindly branches. There’s no need to use pruning paint.

To encourage height, prune out lower branches and leave just one, two, or three trunks. For a more shrub-like appearance, trim the upper branches.

Where to Buy

If you’re looking for live plants, consider these from Amazon. You’ll get two newly sprouted plants.

Texas Mountain Laurel Newly Sprouted Plants via Amazon

If you’d like to start with seeds, you can get packets of five seeds via Amazon.

Managing Pests and Disease

Let’s start with the good news. Deer leave this one alone, so nothing to worry about there.

The bad news is that this plant is plagued by Uresiphita reversalis, aka genista caterpillar or sephora worm.

A Texas mountain laurel bush, with purple flowers and bright green foliage in bright sunshine in a city park with the buildings in soft focus in the background.

This yellow-bodied immature moth can strip the leaves off a Texas mountain laurel in no time flat, though the foliage almost always grows back and the plant suffers no permanent damage.

The caterpillars form loose webbing on the plants they’re decimating.

Control these one-inch-long snackers with Bacillus thuringiensis.

Best Uses

Texas mountain laurel makes a lovely specimen tree or shrub, which is primarily how I see them grown in Austin.

A Texas mountain laurel bush pruned to a tree-shape, planted in an urban area surrounded by buildings and other small shrubs in bright sunshine.

You can also create a tall screen with these, by planting several in a row and letting them bush out.

Quick Reference Growing Guide

Plant Type: Shrub Flower / Foliage Color: Purple; dark green
Native To: Texas, New Mexico, Mexico Maintenance: Low
Hardiness (USDA Zone): 7b-11 Tolerance: Rocky soil, drought
Bloom Time / Season: Late winter, early spring Soil Type: Poor to average
Exposure: Full sun to partial shade Soil pH: Above 7.2 (alkaline)
Spacing: 10 feet Soil Drainage: Well-draining
Planting Depth: Seeds: 1/2 inch; transplant: same depth as root ball Water Needs: Minimal
Height: 15 feet Uses: Specimin or screen
Spread: 10 feet Family: Fabaceae
Growth Rate: Slow Genus: Dermatophyllum
Attracts: Butterflies, bees Species: secundiflorum
Pests & Diseases: Uresiphita reversalis

A Rose of a Different Name

Gardeners looking for a tough evergreen tree or shrub that perfumes the air each spring with a floral scent that stops traffic should consider Texas mountain laurel.

A close up of a Texas mountain laurel shrub with purple flowers and developing seed pods in light sunshine, fading to soft focus in the background.

Lousy soil? No rain for weeks? Hungry deer? No problem. D. secundiflorum takes it all and comes out smelling like a… glass of grape Kool-Aid?

Have you grown Texas mountain laurel? Share your tips and thoughts in the comments section.

If you’d like to learn more about growing other shrubs, check out these articles:

© Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Originally published on January 23, 2020. Last updated: March 9, 2020 at 17:16 pm. Product photo via Amazon. Uncredited photos: Shutterstock.

About Gretchen Heber

A former garden editor for a daily newspaper in Austin, Texas, Gretchen Heber goes through entirely too many pruners and garden gloves in a year’s time. She’s never met a succulent she didn’t like and gets really irritated every 3-4 years when Austin actually has a freeze cold enough to kill them. To Gretchen, nothing is more rewarding than a quick dash to the garden to pluck herbs to season the evening meal. And it’s definitely time for a happy dance when she’s able to beat the squirrels to the peaches, figs, or loquats.

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