Predictable Pineapples
by Barb Henny
Pineapple flowers are exotic and interesting. Photo by Barb Henny
On New Year’s Day, instead of watching football on TV, I slip outside to my hobby greenhouse. There I mix up a solution in a small plastic bucket and pour it into the throats of five or six pineapple plants.
By St. Patrick’s Day, the pineapples will flower. By the 4th of July, I will harvest golden, ripe delicious pineapples. Predictably.
The secret to getting pineapples to produce fruit on schedule is ethylene, a naturally-occurring gas that acts like a plant hormone. Rotting fruit produces ethylene gas, and I’ve tried that method to make pineapples bloom. I’ve put rotten apples on my pineapple plants and covered them with a thin sheet of plastic to keep the gas contained. But the plastic did not deter hungry raccoons from stealing the apples in the middle of the night.
Smoke from wood fire also produces ethylene. When I saw a bottle of Liquid Smoke at the grocery store, I thought it might emit ethylene. I took it home, mixed it with water and poured it into the throats of the pineapples. Within minutes every wasp, bee, hornet and yellow jacket in the area buzzed into my greenhouse! It must have smelled yummy to them, but I fled. Eventually the barbecue odor fanned itself out, but six weeks later… not a sign of pineapple flowers.
Harvest sweet tropical summer fruit — right on schedule. Photo by Barb Henny
Christopher Columbus took pineapples from the Caribbean to Europe in the late 1400s. By 1540, the Botanical Garden in Padua, Italy was growing New World crops such as maize, yams, sunflowers, artichokes and pineapples. By the 1660s, wealthy English merchants boasted of “pinerys” on their estates.
But by the 1800s, Europeans were moving pineapple production back to the tropics. They established commercial pineapple plantations in India, the Philippines, Malaysia and throughout the Caribbean.
Pineapple plantings were established in Florida around the 1840s and by the 1890s Jensen Beach was known as the Pineapple Capital of the World. Acre after acre in the Indian River district was planted to the crop.
Cut an inch of fruit off with the foliage. Photo by Barb Henny
Pineapples do better with a little shade, so growers began to grow them under lath houses. When freezing weather came in the 1870s and late 1880s, growers lit nighttime fires within these structures to keep the pineapples alive — and noticed the positive effects of the smoke on the timing and ripening of the crop.
Eventually pineapple production in Florida could not survive a series of freezes alongside increased competition at the turn of the century. But worldwide, wherever pineapples were grown, lighting smoky fires to generate ethylene became standard crop production practice.
In the 1930s, sprays of calcium carbide replaced wood smoke to produce the ethylene. Then in 1963 a chemical called ethephon was invented. When ethephon is mixed with water, it produces ethylene gas. Ethephon is now used on many crops, including cotton, wheat, mango, rice and coffee. And pineapple.
Clean off excess fruit before placing the top in potting soil. Photo by Barb Henny
Local garden centers, Ace Hardware and the Internet carry ethephon under the product name, Florel®. Mix Florel® with water according to package directions, apply the solution to your pineapple plants and you should have flowers within 60 days and fruit within 150 to 180 days.
Don’t put Florel® on any other plant! It is labeled for bromeliads (pineapples are bromeliads), but most importantly, ethylene causes many plants to drop all of their flowers and leaves. Do not treat your pineapple with Florel® in an unventilated greenhouse containing other flowering plants.
To start pineapple production, buy a pineapple in July or August at any grocery store or produce stand. Select a ripe one with healthy-looking leaves on top. Take it home, cut off the top and clean it of excess fruit. Then within 24 hours, plant the top into a three gallon or larger container (mature pineapple plants can grow up to three feet across). Use any well-drained commercial potting mix and fertilize regularly with a well-balanced fertilizer. Place in bright light but not direct sun.
Mix and pour Florel® into the throat of the plants. Photo by Barb Henny
When cool weather arrives in the fall, make sure your pineapple is in a protected area… perhaps in a hobby greenhouse. This will keep the plant actively growing and ready for the Florel® treatment. Low temperatures can slow the effects of flower formation.
I treat sjx pineapple plants with Florel® on January 1, six more on February 1 and six more on March 1. I harvest fresh pineapples in July, August and September. In the past, I have forced fruit into the cooler months for harvest in October and November, but I find that these are not quite as sweet. In high summer, they are oh so sweet and aromatic!
And that delicious aroma, wafting across the breeze on a warm summer night, is another reason to keep pineapples inside a hobby greenhouse. Closing the door at night keeps hungry, marauding raccoons off the ripe fruit — or at least it slows them down.
Barb Henny has been a gardener in Zone 9 for 40 years.
© 2013 Barb Henny. Originally published in Florida Gardening, Dec / Jan 2013. Reprinted by permission. All rights reserved.