HMNS greenhouse teaches how to plant a butterfly oasis in your back yard

They float on the wind, decorate your back yard in the spring and summer, and inspire warm emotions with their delicate wings. They seem carefree, at home in any meadow, but butterflies have more specific needs than we might imagine.


Monarch butterflies don’t live just anywhere; they need habitat, too!

As urban sprawl continues to grow, reducing green space and native plant growth, natural butterfly habitats are shrinking. Butterflies require specific plants on which to feed and lay eggs. Caterpillars are finicky eaters.

Soni Holladay, Houston Museum of Natural Science Horticulturist and Greenhouse Manager, will lead a class Saturday, April 18, beginning at 9 a.m., to share information with the public about how best to plant a garden that will attract native butterfly species, creating a backyard butterfly nursery.

Holladay’s main concern is planting tropical milkweed to attract the famous migratory monarch butterfly. Though tropical milkweed is easier to grow, scientists have discovered it may play a part in declining monarch populations.

A parasitic species of protozoan called Ophryocystis elektroscirrha, or simply Oe, grows on the body of their monarch hosts. When infected monarchs land on milkweed to lay eggs, Oe spores slough off and are left behind. Caterpillars, which eat the milkweed, ingest the spores and become infected.

When the protozoans become too numerous, they can overwhelm and weaken individual butterflies, causing them to suffer. Several heavily infected monarch can take a toll on the local population. Oe can kill the insects in the larval or pupal stage, as well, before they can reach full adulthood.


Tropical milkweed survives the Houston winters, making them a perennial plant and a possible danger to monarch butterfly populations.

Native milkweeds die off every year and grow back in the spring Oe-free as part of their cycle, but the evergreen tropical milkweed remains standing year-round, providing a vector for the protozoan to spread.

“We’re advising everyone who plants tropical milkweed to cut it back once a year or more,” Holladay said. Much like their native cousins, the tropical variety will return later, a healthy habitat for butterflies.

Holladay’s class will offer more details about this and other butterfly-raising issues. After the class, guests will tour HMNS greenhouses and our on-site butterfly-rearing operation. Tickets $23, all ages. Native milkweed plants and other seeds will be available to get you started.

Flame on!

People come to the Cockrell Butterfly Center to see butterflies, but are often equally entranced by the lush plants that provide the setting.  The plant life has multiple functions.  One, since most of the butterflies we display in the center are from tropical rainforests, we try to duplicate their native environment and conditions to make them feel at home (and hopefully to maximize their short lifespans). 

Warszewiczia coccinea

Warszewiczia coccinea growing
in the Cockrell Butterfly Center

Second, some of the flowering plants provide food (nectar) for the butterflies.  And third, we try to find plants that are interesting and attractive to our human visitors.  We keep all these things in mind when selecting a plant for the exhibit. 

One plant in particular that fills all our criteria is the Rainforest Flame Tree, or Warszewiczia coccinea, as it is known botanically. 

This member of the coffee family is native to Central and South America and the West Indies.  It is the national tree of Trinidad (another common name for this tree is “Pride of Trinidad.”) It usually grows to around 25 feet tall, but can reach greater heights in different growing conditions.  In Costa Rica, this tree is considered a canopy tree and can reach 50 feet. 

The leaves of the tree are somewhat corrugated and are located oppositely on the stem.  But the best thing about it are the showy flowering branches.  They are located on the end of a branch and are placed at the nodes. 

Each flower cluster is accented by a red bract, sort of like a poinsettia flower would have.  In fact, another one of the common names for this plant is poinsettia tree.  The flower cluster, which is orange, is very appealing to butterflies because it is loaded with nectar.  In any given moment, several species of butterflies can be seen visiting the flowers. 

Although Warszewiczia warrants more use in tropical gardens, it is rarely seen outside botanical gardens.  One reason for this is that it is difficult to propagate.  Usually, plants in the coffee family can be propagated by seeds or by cuttings. Warszewiczia, on the other hand, shows little success with either method.  After several years of trying in the greenhouses of the Butterfly Center, just one cutting has ever proven successful.  

Due to its rarity, Warszewiczia is highly sought after by plant collectors.  If a collector was lucky enough to acquire one of these plants he would want to live in a warm environment such as Houston.  Any environment colder than Houston would require a greenhouse to overwinter the plant.