ORNAMENTAL PLANTS TO AVOID IN YOUR CENTRAL TEXAS GARDEN

Fall is here and it is the best time of year to plant trees and shrubs for next year’s garden enjoyment.   We see many articles and resources about best and recommended plants to grow in our region, with emphasis on native and adaptive plants well suited to our climate and environment.  However, there is a flip side to that coin - plants to avoid for various and very good reasons.    

First of all, we should avoid the spreading of non-native invasive plants that overwhelm and threaten our local native plants.  A list of these is found in the City of Austin’s “Grow Green” book - free at any nursery or plant center in Austin.    But in addition to those recommendations of plants to avoid,  I see many other plants sold at local nurseries that can create major problems in your gardens and should be avoided.   Here’s my top 12 “no grows”.  

• Photinia fraseri - The "Red Tip Photinia does produce dramatic color on new growth but has many reasons not to use it.  It grows rapidly and ultimately into a small tree,  yet is planted like a shrub. As a member of the rose family it is subject to a fungal disease (black spot) and requires considerable pruning maintenance.  Most often,  they are planted too close to foundations and to each other for hedge effect.   This inexpensive and a widely overused plant comes with many potential problems for the homeowner.

• Artemesia vulgaris -  This species of Artemesia spreads rampantly throughout your garden from roots which can spread 5 - 10’ underground and send up new plantlets everywhere!  If even a tiny piece of root is left in the ground, a new plant will emerge.  It is extremely rampant, yet a variegated variety (Oriental Limelight) is pending a patent and it is being widely sold at nurseries.  That would be like buying variegated nutgrass for your garden!   Container grow only.

Artemesia vulgaris 'Oriental Limelight" - Beautiful but a menace in the garden

• Euonymus japonica - This plant has bold variegated color to offer along with Euonymus scale and other pests,  frequent reversion to solid green,  and short life.   It is an inexpensive plant that is overused in landscapes.  However, E. fortunei does not have the same problems as E. japonica .
• Wax Leaf Ligustrum  (Ligustrum japonica) -  The green or wax leafed ligustrum is a rapid grower,  has a pungent smelling white bloom in spring,  and ultimately grows to small tree proportion but is planted as a shrub.  It is one of the most overused and inexpensive shrubs used in initlal landscapes and if often planted too close to foundations and to each other.  Watch out for wax scale also.
• Variegated Chinese Privet (Ligustrum sinense)  -  This colorful small leafed shrub is overused and inexpensive but generally looks very nice in landscapes until it begins to revert to solid green!  This is a problem!   It spreads rampantly by seed endangering our native plants.  
• Nandina domestica (Heavenly Bamboo) -  The red berries are beautiful but all one needs to do is take a walk in an urban or rural nature area and see this plant coming up everywhere from bird spread seed.  It is very invasive and endangers our local native plants.  Only non-berry producing varieties should be used.  Nandina can’t take our intense bright sunlight and heat of summer well either.
• Indian Hawthorne (Raphiolepis indica)  -   Although popular for it's spring bloom,  this plant is very often infected with scale, a sooty mold and other diseases.   This plant tend to be overused in southern landscapes, contributing to the spread of these undesirable infestations.  It favors acidic, organic soil so is not suited well to TX hill country. 
• Chinese Wisteria (Wisteria sinsensis)   -  Spring blooms are beautiful and fragrant but this vine can grow almost 12" per day and strangle anything nearby.  It is especially invasive and hard to control - almost like Kudsu.
• Pampas Grass  (Cortaderia selloana)  -  People who plant this regret it!  Clumps get extremely large and  thick,  blades contain sharp cutting edges, and it takes a stick of dynamite to remove!
• Running bamboos  -  Bamboos are a fascinating plant, but can run rampant among your garden area unless container grown.  They are very difficult to remove, once spread out, so avoid running varieties unless you have acreage to spare.  Clumping bamboos, also spread but from the base, not runners, and can be controlled with periodic basal trimming. 
• Clerodendrum bungii (Cashmere Bouquet)   -   This beautiful root hardy sub-tropical plant is enjoyed for it’s fragrant large cluster of bloom,  large foliage, and tropical look, but spreads rampantly from underground roots, plus wind and bird dispersed seed and can create it’s own jungle in short order.  Unless contained, avoid it in the garden.
• Pittosporum tobira -  The Pittosporum also gets large,  requires much pruning to maintain,  and is subject to being damaged at below freezing temperatures and wax scale infestation.

This of course is not a complete list so do your homework before going plant shopping.  I recommend going go a nursery or garden center with a specific list of researched plant selections in mind, and if not available look elsewhere.  I let my fingers do the walking (telephoning local sources) when looking for a specific plant.  Before deciding on an alternative plant, I once again do my homework first.  So, Fall; is a good time to be thinking about next year’s ornamental garden and getting new permanent plantings in place so they can become well established by spring.  This is especially true of deciduous and spring flowering trees and shrubs.  Knowing which plants to avoid is as important as those best suited for your garden.    

THE WONDERFUL WORLD OF BROMELIADS

Bromeliads are one of the best kept secrets in the plant world.   My goal  is to introduce you to the wonderful world of bromeliads and try to let you know what you are missing if they are not part of your plant collection.

They are diverse, fascinating, and relatively easy to grow.  There are 54 genera and 3,168 species of identified bromeliads throughout the world.  They have been hybridized extensively and many new striking plants have resulted with both bloom and foliage that offer more color than any other plant I am aware of. Because bromeliads are "different" looking than traditional plants and most people consider them exotic, therefore perceived as hard to grow, bromeliads have not caught on among  plant enthusiasts nearly as much as they deserve to. Newly discovered or hybridized plants often sell to collectors for big bucks, but in a matter of years become affordable to most people as they are reproduced asexually by dividing "pups" from the developed plants. Most plant nurseries don't offer bromeliads in wide varieties so the really nice and choice plants most likely will need to be purchased from specialty growers. 

Bromeliads in their native habitats (unique to the Americas with one exception in western Africa) grow in such diverse places as 13,000 ft elevations to sea level, rain forests to deserts among cacti and succulents, and even as far north as the Virginia coast and as far south as southern Argentina.. In nature, epiphytic bromeliads provide habitat for frogs, aquatic insects, and lizards as part of the tropical and subtropical ecosystem.   Some are true "air plants" like Spanish or ball moss (Tillandsia) while others are terrestrial like those sweet pineapples we enjoy as a popular fruit. . Most are epiphytic deriving their nutrients from their cupped shape.  The optimum temperatures for bromeliads range from 70 to 90 in daytime to 45 - 60 at night F.   Most bromeliads like good air circulation and 50 - 75% humidity.    There is no general guidelines for growing bromeliads in general as they are so diverse.  You need to know about the specific genera and species and what it takes to grow it well - but with that knowledge, you will find them relatively easy to grow and enjoy.

INFLORESENCES can be cupped, bracted, branched, single spiked, or insignificant. FOLIAGE can be smooth edged (Tillandsias), spined, or succulent. BLOOM PERIODS range from less than one week (Billbergias) to greater than a month (Vrieseas). RELATIVE SIZES can range from less than one inch to greater than three feet wide and tall. These variances can occur within the same genera of bromeliads depending on the particular species.

Tips on Growing and Enjoying Bromeliads

• For  epiphytic (non-terrestrial) varieties, we grow bromeliads in small pine bark as a soil base. This provides excellent aeration and circulation for the roots that form, and provides sufficient support for the plant. For terrestrials, use a loose and light organic soil mixture. For small epiphytic tillandsias, mounting them on driftwood or cork is an excellent and healthy way to display them. 
• • Location is everything! Since different bromeliads prefer different levels of light, they will let you know how to please them. If the foliage becomes bleached or burned, reduce the light. If the plant isn't producing  the color you know it should have, increase the light. Finding the right level of light makes all the difference in bringing out the colorful qualities of these plants. Good air circulation is a common and vital need to all genera of bromeliads. 
• • Bromeliads should not be fertilized regularly unless you are trying to increase pup production. There are some exceptions. Tillandsias and Cryptanthus respond well to regular fertilization. Fertilization will reduce the coloration in most bromeliad hybrids that are noted for their color., e.g. Neoregelias and Billbergias. When fertilizing, use a liquid soluble 20/20/20 fertilizer at half the recommended strength.  Never use urea based nitrogen fertilizer.  Avoid mineral salts of any kind.  Most city water supplies are fine for bromeliads.  Never mount bromeliads on chemically treated lumber.   Water with pH of 5.5-6.5 is preferred (avoid alkaline water).  
• • How to display bromeliads is always a good question. Some suggestions follow. They can be grown in large hanging baskets with three plants average per basket. We group the plants by commonality, e.g. Neoregelias in one basket, Aechmeas in another, or mixed genera that share the same light requirements.  Other ways are to display them on single poles with pot loops in spiral form. Yet another way would be to incorporate them into a ground level display by digging out a hole, placing a one gallon nursery container in the hole, and inserting an 8" plastic pot into the nursery container with the plant potted in small pine bark. This gives the appearance they are terrestrial without them ever touching the soil. As long as the basic cultural requirements are met, bromeliads can be displayed in a number of other imaginative ways. They can also be attached to trees to resemble their natural habitat. However, collector or rare plants might best be grown as individual plants for greenhouse or other special display. 

After the plant flowers, it will produce "pups" or young plants then die. The young pups will take over the next generation. Pups should not be removed until visible root structures can be seen at their base or they are at least 1/3 to 1/2 the size of the mother plant. Make sure the pups are cut off with a solid base.  Some bromeliads reproduce so abundantly, you'll be sharing them with friends.  Dead flower stalks can be cut off if unattractive until the mother plant dies.  All bromeliads require winter protection in central Texas, except the ball moss (Tillandsia rotunda), seen in our native oak trees, but  most can adapt as house plants during winter months.  Exceptions might be Tillandsias (air plants) which require good air circulation and high humidity.  

For more information about growing bromeliads, go to www.centraltexasgardening.info/bromeliads.htm .  There you will find more resources for learning about these fascinating and easy to grow plants. 

A patio display of colorful bromeliads

TROPICAL PLANTS AND CENTRAL TEXAS

On a recent 12 day eco-tour of Costa Rica, I was astounded by the lush, fast growing, beautiful plants, flowers, and the wildlife they attract. In fact, Costa Rica has created a healthy eco-tourism economy by deciding to leave significant portion ot their natural environment alone.  This was accomplished by placing 26.6% of their land into national parks plus other preserves totaling 31%. This fact drew us  to see for ourselves a pristine and healthy rain forest ecosystem that thrives from sea level all the way to volcanic mountain ranges above 6,000 ft.

A tropical but ground hardy Butterfly (Hedychium)  Ginger blooming in our Austin garden

There is a combination of native and introduced plants from similar tropical regions around the world, but all share one thing in common – they not only survive, but thrive in their chosen adaptive environment. How I wished I could have dug up every different plant I saw and put it in my central Texas garden – wishful dreaming!! In fact, when living along the Gulf coast in SE Houston, I tried growing every exotic plant I thought I could get through the winter months. But on our trip through Costa Rica, I came to a clear understanding of why growing native and adaptive plants is important in any region of the world. Never can we duplicate the rain forest's tropical environment of Central America and never can Costa Rica duplicate the unique beauty of the dry climate plants that grow in Texas. I also observed the very important relationship and interdependence between the plants and wildlife that occurs in a specific ecosystem.

That little Ficus plant bought in Austin grows to over 100’ tall and wide with aerial roots in it’s native environment producing fruit eaten by monkeys, birds, lizards, and other wildlife. The philodendron and other tropical foliage plants grow leaves over 2’ wide as they meander up huge kapok trees up to 20’ diameter. The Episcas and gesneriads we grow as indoor potted plants are used as a year round ground cover. This is not to say we shouldn’t grow these plants as house plants or seasonal outdoor plants, but to really appreciate a plant’s potential, it must be seen growing in its ideal, natural habitat. So, the tropics beckon and amaze those who can travel there to see firsthand, the glory of the tropical rain forests that are being destroyed at an alarming rate during our lifetime.

OK, so we can’t grow many of the tropical beauties well or at all in Austin, such as Heliconias, many gingers, tropical Hibiscus, various tropical fruiting plants, Crotons, ti plants, orchids, bromeliads, ferns, etc, but that doesn’t mean we can’t be fascinated enough to want to learn about them. I find this to be as stimulating as actually trying to grow the plant. At least it will live in my mind, and not dead in my garden. I do grow some tropical plants for seasonal color in my garden, either as an annual, or by greenhouse overwintering, but never expect them to come close to achieving what they can when grown in their native environments. That's OK.


So, if you want to have a “Tropical Look” garden, that is possible. Some plants associated with the tropics can be surprisingly adaptive to even our Austin environment, if you are not too choosy. There are many cold hardy palms, cycads, and citrus that can provide a year round tropical look. Knowing which ones is the trick. Plants that grow in the tropics but could survive as root hardy in Austin in a protected, shaded area include large leafed philodendron, Clerodendron, Duranta, Plumbago, Pride of Barbados, Cannas, Hedychium and a few species of Gingers. Other hardy native and adaptive plants that possess a tropical look include the Mexican Bird of Paradise, Rose of Sharon (in place of the Hibiscus rosa-sinensis), Crinums, hardy Manihot, Oleander, and Esperanza.  Many tropical plants look very much like temperate zone plants, but are genetically tropical. Texas and Costa Rica do have some plant types in common . For example, agaves and yuccas are found frequently in the tropics, albeit different species, but they still add to the diversity of the tropical ecosystem. Climate wise, it is much cooler in central America than central Texas in summer. Average temperatures range from 70 – 85 degrees year round and this stability in temperature allows such a diversity of plant life to thrive whereas we are limited by extremes in environmental and climatic conditions.

Also, in the tropics, rainfall is greater than 100 inches per year so plants recommended for a tropical look in central Texas are those that can adapt to our 30 inches per year in central Texas but still provide a tropical feel. I always recommend that any gardener study the native region that a plant comes from in order to understand how to grow it best.  By simulating it as much as possible, the more successful we will be in growing plants not native to our area. But bottom line is that we shouldn’t push past rationality which will only lead to gardener’s frustration. I have accepted the fact that there are just some plants I can’t grow well or at all, so why create unneeded stress when gardening is supposed to be therapeutic and relaxing. Go with the flow and grow what grows best in our unique ecosystem instead of dreaming of all the plants you wished you could have in your garden from elsewhere. We all long to grow what we want rather than what we can.

That’s what vacations and travel are for – to explore the wonderful world of plants and wildlife in different ecosystems around the world where they live if possible. Put Costa Rica on your wish list!!

Tropical Garden - Costa Rica

Tropical Garden - Austin TX