Edible Gardening Series: Question of the Week – tomatoes
By Sarah Bostick and Carol Wyatt-Evens
Gardening in Florida can be incredibly rewarding and incredibly frustrating, at the same time. If you are new to the region, you soon learn that gardening in the Sunshine State can quickly become a full-time job. While our subtropical climate is perfect for growing an abundance of different vegetables, fruits, and herbs, it also can present some overwhelming challenges.
We can help! UF/IFAS Extension Sarasota County agents and staff have created an online edible gardening resource center. The website features short videos from our 25-episode “Edible Gardening Series” webinars, along with blog posts and resources lists for episodes. Get help on an array of topics that befuddle many gardeners.
This week’s Question of the Week:
My tomato plants are not happy with all the rain we have. What can I do to save the leaves from disease?
Tomatoes are a true garden treasure. But like most storybook treasure hunts, growing a perfect tomato can be a grand, epic adventure wrought with perils, pitfalls, and a very steep learning curve.
Tomatoes are a challenge to grow regardless of where you live in the world. If you happen to live in Florida or other very hot and humid climates, they can be especially challenging. One of the greatest challenges is preventing and managing disease.
There are many layers to preventing and managing diseases in tomatoes, but one of the most fundamental is actually quite simple: air movement. Many tomato diseases need damp leaves to thrive. Helping your tomato leaves dry out quickly after rain or morning dew is important and the best way to achieve that is to make sure that wind and air can easily pass through the plant.
One way to understand the importance of air movement is to think about a load of laundry. Imagine that a load of laundry has just finished. You have three options: put the damp laundry in the dryer, hang the laundry on the laundry line to dry in the sun, or leave the wet laundry in a pile in hopes that it will dry itself. Leaving wet laundry in a pile will result in stinky, mildewy, clothes that need another run through the washing machine! Hanging your laundry on the line is slower than putting it in the dryer, but it gets the job done.
Wet leaves, just like wet fabric, are a perfect place for mold, mildew, and bacteria to thrive. When thinking about tomatoes, you want to aim for the “laundry-on-the-line” option of drying leaves out. Here’s how to achieve that goal:
- Appropriate spacing: A mature tomato plant is big – very big! In Florida, a healthy, mature tomato plant can be over six feet tall and three feet wide. It is a very good idea to plant tomatoes 2 to 2.5 feet apart from each other. Planted too close to one another, branches and leaves intertwine, preventing air from flowing around and through each plant. This spacing will likely seem excessively far apart when you are transplanting small seedlings, but it is ideal for the health of the plant.
- Keep the tomato plants off the ground: Just like that heap of wet laundry mildewing in a pile, tomatoes that sprawl on the ground will stay wet and quickly have issues with diseases. Tomato plants are often referred to as “tomato vines”, but they are actually not vines because they have no ability to keep themselves upright. There are endless ways to keep your tomatoes vertical and this website lists 53 of those options along with helpful instructions, cost estimates, and photographs of each option.
- Pruning tomato plants: There are many opinions and conflicting study results about how much to prune, when to prune, where to prune, and whether or not to prune at all. The best way to figure how much to prune your tomatoes is simply to give it a try! If you are growing more than one tomato of the same variety, try pruning one tomato and leaving the other unpruned. Do your own citizen-scientist pruning experiment.
If you are interested in giving pruning a try, here are some of the basics:
“Suckers” are the part of tomato plants that many farmers and home gardeners choose to prune off. Suckers sprout from the space where a branch emerges from the trunk of the tomato plant. Suckers will eventually grow to be the same size as other branches of the plant and will produce fruit, just like the main branches. However, if no suckers are removed, the plant will become a dense jungle of foliage that is too thick to allow free movement of air. By removing some or all of the suckers, you are ensuring that air can move through the plant. Air movement helps to prevent disease thereby prolonging the healthy, productive life of the plant.
About once a week, search your tomato plant for new suckers. When the suckers are no more than about 3 or 4 inches long, you can snap the sucker off with your fingers. When the suckers are a bit bigger, you will need to use clippers to remove the sucker. Make sure that you remove suckers on a dry, sunny day so that they plant can quickly heal. Pruning during wet weather opens the plant up to disease. It is a good idea to dip your clippers in rubbing alcohol between plants to prevent the spread of disease.
Leaves that make contact with the ground tend to stay wet much longer than other parts of the plant. Even if you choose not to remove suckers, it is a good idea to remove any leaves or very low-hanging branches that touch or nearly touch the ground.
Factsheets and resources for gardening in Florida:
UF/IFAS EDIS has an array of informative publications on gardening and integrated pest management that can be found at the links below:
- Natural Products for Managing Landscape and Garden Pests in Florida:
- Organic Vegetable Gardening in Florida:
- Pest Management Topics
The Edible Gardening Series and blog series is a partnership between the following UF/IFAS agents and Sarasota County staff:
- Sarah Bostick, Sustainable Agriculture Agent
- Carol Wyatt-Evens, Chemicals in the Environment Agent
- Mindy Hanak, Community & School Gardens Educator
- Kevin O’Horan, Communications Associate