When to Cover Tomato Plants at Night

Tomato plants are some of the most common vegetable plants grown in home gardens. They deliver juicy, flavorful fruits that are perfect for making salads, sauces, soups, and other yummy recipes. However, tomato plants are vulnerable to various pests, diseases, and environmental stressors such as high winds, heavy rains, and low temperatures. To protect your tomato plants and ensure a healthy and bountiful harvest, you may need to cover them at night. But when should you do it? Here's what you need to know.

Understanding the Temperature Needs of Tomato Plants

Tomato plants are sensitive to sudden temperature changes and extreme weather conditions. Their ideal growing temperature range is between 70°F and 85°F, with an optimal range of 75°F-80°F. When the temperature drops below 55°F, tomato plants can suffer from chilling injury, which can manifest as yellowing leaves, stunted growth, and reduced fruit production. To avoid chilling injury, it's essential to cover your tomato plants when the temperature is expected to drop below 55°F at night.

Checking Your Local Weather Forecast

The best way to determine whether you need to cover your tomato plants at night is to check your local weather forecast. Most weather apps and websites provide hourly updates that can give you a good idea of the temperature and weather conditions for your area. Make sure to pay attention to the overnight temperature, wind speed, and precipitation forecast. If the temperature is expected to drop below 55°F, and/or there's a chance of high winds or heavy rains, it's wise to cover your tomato plants with fabric or plastic sheets.

Choosing the Right Cover Material

When it comes to covering your tomato plants, you have several options. The most common ones are fabric and plastic sheets. Let's take a look at the pros and cons of each material:

Fabric sheets: These are made of soft and breathable materials such as cotton, polyester, or burlap. Fabric sheets are lightweight and easy to handle, and they allow air and moisture to pass through, which reduces the risk of fungal diseases. However, fabric sheets don't provide as much insulation as plastic sheets, and they may not be suitable for extreme cold temperatures.

Plastic sheets: These are made of polyethylene or other synthetic materials that are waterproof and insulating. Plastic sheets are more effective at trapping heat and protecting plants from freezing temperatures and harsh weather conditions. However, they are not breathable, which can create a humid and stuffy environment that favors mold and mildew growth. Plastic sheets can also be heavy and hard to maneuver.

Depending on your climate and the severity of the weather, you may choose to use one or both types of cover materials to protect your tomato plants.

Applying the Cover Correctly

Once you have determined when and what to cover your tomato plants with, you need to apply the cover correctly to ensure maximum protection and ventilation. Here are some tips:

Place the cover before sunset: Ideally, you should place the cover over your tomato plants before the sun sets to allow enough time for the warmth to build up inside.

Secure the edges and corners: Use stakes, bricks, or other heavy objects to anchor the cover to the ground and prevent it from blowing away in high winds. Make sure to seal off any gaps or openings that can allow cold air, rain, or insects to penetrate.

Provide ventilation: To prevent humidity buildup and air stagnation, you need to provide some ventilation to your covered tomato plants. You can do this by leaving some gaps or holes in the cover, or by propping up the edges for a few inches to allow air to circulate. However, don't overdo it, as too much ventilation can defeat the purpose of covering.

Remove the cover in the morning: As soon as the temperature rises above 55°F, or the weather clears up, you should remove the cover to avoid overheating or suffocation of your tomato plants. Make sure to keep an eye on the weather changes throughout the day and be ready to cover your plants again if needed.

By following these guidelines, you can protect your tomato plants from the cold and other weather hazards, and ensure a healthy and delicious yield. Happy gardening!