Growing food in the country’s hottest city is no joke.
Miami producers and plants alike are hardened veterans in roughing out the bugs, the plagues, and the heat. It’s why you can find luscious passionfruit, lychees, mamey and other unique fruits flourishing in our backyards along with more beloved staples like bananas, avocados, and mangoes. It’s how strawberries, lettuce, and sweet corn ripen here even in the dead of “winter”. But insert rapid climate change- intensified storms, warming temperatures, rising sea levels, etc. and it’s become tragically harder and harder for the plants we typically grow to “take the heat”. In fact, a recent study from the Economic Research Service compared how the agricultural productivity of different states would fare under climate change over the next two decades, and Florida was projected to be among the most negatively impacted.
Many crops in Florida are already grown at temperatures that exceed or at the higher end of their optimal range. The higher temperatures lead to greater pest/disease pressure, increased demand for water, and impaired yield. For example, say you’re growing the most popular garden vegetable- the tomato. The optimal growing temperature for a tomato is 66-77℉. Temperatures above 90 °F degrees can cause pollen sterility, but days like those are only becoming more common in Miami where between 1970 and today there’s been over a 20% increase in 90+°F days per year. The effect is growing seasons cut short and a northern migration of crops’ zones of production. What’s a 305-grower to do?
Dr. Alan Chambers, a fruit breeder at the Tropical Research and Education Center (TREC), knows that the right crop can make the difference between tropical paradise and pestilent hellscape. Using genetic insights, he’s discovering new cultivars of crops that will work with our evolving South Florida climate and keep local farmers in business.
One crop that is ripe with potential is the vanilla orchid.
While some home gardeners try their hand at it, vanilla is not commercially grown in South Florida…yet. Wait at least 5 more years, says Dr. Chambers. Vanilla is a tropical plant that is well-suited for local production. Our hot rainy summers trigger rapid growth; the dry, increasingly drought-like conditions of winter encourage flowering. In fact, established plants may not need any additional irrigation except in extreme cases. And because vanilla is a shade-loving vine, it could be a lucrative secondary crop using a range of tropical fruit trees for structural support. The four species native to Florida’s preserves introduce unique and useful traits not seen elsewhere in the mostly homogenous vanilla industry. For example, not needing to manually pollinate seeds cuts down on a huge expense in commercial production. Resistance to major pathogens like fusarium oxysporum makes production more locally adaptable. The logistics of harnessing these traits are not simple. “The question is, is there a gene in that plant we can hybridize into the commercial type and take care of the number one pathogen,” Dr. Chambers explains.
Where do dreams of local vanilla lead us?
Stories of climate change are packed with doomsday language and for good reason. Certain harsh realities will continue to grow; more heat will attract more pathogens and generally require more inputs. But the emerging story of vanilla is a seed of hope for growers looking to invest in novel crops. While there is no “Planet B”, the dream team at TREC is researching the many Plant B’s. These plants will be adapted to more tropical conditions. For example, Chambers says lengthening intervals between freeze events could allow for production of crops like cacao or breadfruit. Today, risks are still too high- even for a profession as fraught with risk as farming. Research mainly focuses on opportunity crops for the here and now like vanilla which may not have been recommended in the past. Ultimately, remaining adaptable is and will continue to be essential to growing abundant local food. That wouldn’t be too bad a forecast… for America’s hottest city.
Meylin is a Plant Science student at the University of Florida specializing in Sustainable Crop Production with a deep interest in closed-loop systems and regenerating soil fertility. When not studying, she can be found writing, running, and taking pictures of critters in the garden. During the summers, Meylin spends time in Miami with her family. Meylin believes food is a great way for people to connect; some of her personal favorites include mangoes, peanuts, and oats.