Native Palm Groves in Dallas, Texas
By Tony Cerbone
It was a shivering, cold January day in Dallas, as I quickly walked from the DART station, (Dallas' light rail train) in the West End, to the Dallas World Aquarium. A blue Norther was rolling in and sleet was forecast. That night it was supposed to go below freezing with temperatures in the 20s°F/ -6C°. I had taken the train, because Dallas is one place you don't want to be driving around in when icy conditions are predicted.
We were meeting for lunch at the Dallas World Aquarium to celebrate a friend's recent business success with his Internet company. Inside the Aquarium, the warm humid air of the enclosed 3-story rainforest was very inviting. The live Toucans, monkeys and lush palms transported you to a South American jungle. A friend commented on how nice it would be to live in an area with such lush palms. I told him that he did. To prove it, the following weekend when the temperatures had gone back up into the 70s°F/ 22°C, we drove 15 minutes south of Downtown Dallas, to an area of gravel pits and swamps.
What you first see as you approach the area is the huge Southside Wastewater Treatment Plant, where the city of Dallas treats more than 100 tons of sludge every day. As you get closer, you see trucks hauling away gravel and sand from the nearby pits. The abandoned pits have filled with water and form a series of ponds and small lakes that have now become part of the Alligator and Palmetto slough preserve, and help regenerate the swamp. Overhead you can see red tailed hawks, while at your feet the tracks of raccoon and coyote. Blue herons and White egrets can be seen fishing along the banks. As you enter the swamp, tall trees predominate. Pecan, Elm, Willow, Oak, and Bois d'arc trees make up the majority of the types of trees you can find there. The swamp therefore is a series of small streams and flooded woodlands. As you walk along the muddy banks you can see large fresh water mussels shell. Most of the plant life is deciduous but it isn't long before you see some green vegetation. The 3-5 feet wide leaves of Sabal minor, or Texas palmetto stand out against the bare ground. All around are seedlings that appear to be blades of grass. Throughout this immediate area are scattered groupings of 10-20 plants, about 8 feet tall, with no trunk. After pushing on in the heavy mud, avoiding the alligators, rattlesnakes and cottonmouths, you come across a ridge. From the top of this ridge is an amazing sight. A huge forest of palms! Lush green palm fronds span this area with the average height being about 8 feet tall, and some specimens about 12 feet. This is the site one envisions when thinking of S. Florida, the Amazon or some other frost free place, but certainly not the Big D.
The palms themselves are almost always found growing in the muddy black clay not the nearby sandy loam. They are not in standing water, but on ridges, that at times can be flooded. Always growing in the shade, not in open sun. My observation is that the bare trees in winter allow the strong southern sun (32° Latitude) to warm the palms. Also they act as a windbreak to the cold Northers blowing off the prairie. In the summer, their thick leafy canopy reduces the scorching desert-like temperatures. This all combines to create a microclimate that has allowed the palms to flourish. The palms must also be very cold hardy since they survived the 1983 winter when the Dallas area had an extended record breaking cold period where the temperatures didn't go above freezing for 12 days. The low temperature at this time was about 5°F.
According to Mary Phinney an archeologist and administrator for the Dallas County's park and open space program, this palmetto swamp with 282 protected acres, is part of a 600 acre swamp that researchers have estimated, goes back anywhere from 10,000 to 100,000 years. So, palms have been in Dallas a long time, and should be used in local gardens more often. Nandinas and hollies are great, but next time why not use a palm. After all they are a native plant and have evolved to take our cold winters and hot summers. Plus, the seeds germinate very easily, and overall are very trouble free.
It is amazing that this beautiful palm forest, which has been growing here for thousands of years, survived the City of Dallas' rapid urbanization. It seems that Mary Whitlow, whose father owned a sand and gravel Company, and the land the swamp sits on, persuaded her Dad not excavate the area containing the palmettos. Mr. Whitlow then offered this undeveloped land to the county and that is how the park was created in 1993.
The area also provides a home to many different types of wildlife. Alligators are very common here, with 27 breeding pairs last counted. Most are in the 3-4 feet long range but one is estimated to be between 10-12 feet long. Its footprint is measured at 8 inches. Their nests can often be seen in the spring. Water moccasins, rattlesnakes, poison ivy and fire ants, are very common throughout and discourage unsupervised visits. Cougars or Pumas, Bob cats, 18 species of turtles, 3 species of mussels, beavers, mink, Alligator gar, (type of fish) are some of the other denizens. This is not like the swamps of East Texas with their bald cypress and Spanish moss. None of these plants can be found here. It is thought that the hotter and drier air in the summer prevents those epiphytes from succeeding here. What does thrive, are the beautiful groves of palms.
These remnant palm woodlands, are the farthest north and west of that plant community in this part of the United States. About 100 miles north of here there are groves in S. E. Oklahoma that are furthest North, but also East. Today, of the 282 acres owned by the county 120 acres is original swamp. The rest act as a protective zone to keep the swamp viable. Dallas' urban palm forest remains unknown to most residents of the Metroplex, but is now protected from further city growth. The last step in conserving this area is controlling poachers. It seems that most of the palms that were visible from the roadside have disappeared over the years. One possible explanation is that people are digging up these readily available plants for home use. The largest groves are deep in the swamp and require wading through alligator and poisonous snake infested areas. I guess in this area we can just let the residents protect themselves.