Florida gardeners know that plants grow fast in the Sunshine State. So it's no wonder that one of the largest trees in the world resides here, an enormous banyan (Ficus benghalensis) that spans more than an acre in diameter.
But what a lot of people don't know is the story behind this mammoth wonder. It was planted in 1925 by Thomas Edison (1847-1931) at his winter estate in Fort Myers, where important botanical research was taking place. Edison, along with associates Harvey Firestone (of tire fame) and Henry Ford (of automobile fame), were looking for a source of natural rubber that would grow in the United States and thought the answer lay in the banyan's milky sap. (It didn't.)
Edison tested thousands of plants on his 14-acre property overlooking the Caloosahatchee River and narrowed the contenders to 40. Ultimately, the common weed goldenrod showed the most promise as a natural source for rubber — but unlike most of Edison's inventions, it never became a commercial success.
Edison is best known for his mechanical and scientific inventions, most notably the practical electric light bulb, as well as the telephone, phonograph, X-ray machine, appliances such as the toaster and iron, even cement — the list goes on. One of the greatest inventors, Edison amassed more than 1,000 named patents for devices, many of which dramatically changed the way we live.
History buffs converge on Edison's winter home, known as Seminole Lodge, to explore the homes, laboratories and artifact museum showcasing scores of his brilliant inventions. But for gardening enthusiasts, the real attraction is outdoors in the numerous tropical gardens, where more than 1,000 varieties of plants imported from around the world are thriving — many planted by Edison and his wife, Mina.
Today, some of Edison's trees have grown so big, they've been awarded "Champion Tree" status in Florida. In addition to the banyan, there's a 99-foot Cuban laurel (Ficus nitida), a 97-foot Cuban royal palm (Roystonea regia), a 102-foot Mysore fig (Ficus mysorensis) and a 57-foot sausage tree (Kigelia africana).
Bamboo — eight varieties grow on the property — plays an important role at the estate; in fact, it's the reason Edison bought the property in 1885. Ever the inventor, Edison thought bamboo fiber could be used as a light bulb filament.
While Edison was busy collecting plants and testing them for their medicinal and scientific value, Mina took a more conventional approach to gardening. Her moonlight garden of white and blue blooms, lily pond garden of iris, water lilies and papyrus, rose garden and other equally colorful and fragrant gardens were the perfect backdrops for the socialite's many tea parties and luncheons.
The Edisons grew vegetables and herbs in raised garden beds and containers, watering them with collected rain water and fertilizing with seaweed. Known as the "Edison Heritage Garden," it has been re-created at the estate to feature the produce of the season. Nearby are a variety of fruit trees the Edisons would have grown, including banana, lemon, avocado, star fruit and calamondin. Mangoes are especially plentiful and run the length of the front entrance.
A water conservationist, Edison also used water from an artesian well to irrigate the tropical gardens, as well as the cement swimming pool, one of the first in the state.
The ultimate souvenir — a potted cutting of an heirloom plant growing on the estate — is available at the outdoor Garden Shoppe. There are begonias, bromeliads, vines, herbs, vegetables, perennial flowers and more exotic and unusual plants, such as lipstick plant, sausage tree, ylang-ylang and red kapok. Plants are priced from about $2 to $50.
Even potted cuttings of that famous banyan planted more than 80 years ago in the hopes of producing rubber are available for about $25 each. Just be careful where you plant one of these champion offspring — they need plenty of room to grow.
Yvonne Swanson is a freelance writer in St. Petersburg and a Pinellas County master gardener. Contact her at firstname.lastname@example.org.