Caring for tomatoes during heat and drought can be a challenge, especially if they’re growing in a container.
When the temperatures reach into the 90s, you can expect to water them daily. In the case of my prize Fourth of July tomato planted in a 14-inch pot, I have to water twice a day.My container is sitting in a shallow saucer that catches excess water that may have drained out too quickly and failed to fully moisten the soil. So, if the soil is dry, the water will still be drawn up into the pot.
When to water makes a difference in the quality of your tomatoes, no matter if they are planted in the ground or in a pot. Excessive wilting from lack of water stresses plants and affects the texture and taste of the fruit. Also, when the plants dry out, the uptake of calcium is interrupted, which causes blossom end rot, the ugly blackened patch on the bottom of the tomato that ruins its looks. So, it’s best to water them in the morning before the sun hits them. In high heat and drought, I water them again in the evening.
If your tomatoes wilt in the heat of the day even though you have watered them well in the morning, the cause is not lack of water. In high heat, plants can’t take up water from their roots fast enough to make up for their loss through the leaves and they often wilt. However, if they have been well watered before the sun hits and weather heats up, the wilting will not be as severe and less damage is done.
To help my prized tomato plant cope with the heat stress, I add my ‘rescue remedy’to the water weekly. The recipe is as follows: 1 ounce of Neptune’s Harvest Seaweed plant food (liquid kelp) and 4 drops of Superthrive vitamin solution mixed in 1 gallon of water.
In a 10-year study at Virginia Tech on bio stimulants, researchers found that seaweed extracts had a profound effect on the stress tolerance of plants.
Fertilizing is not recommended during drought and temperatures above 85 degrees but my tomato is planted in a combination of good quality potting soil and compost that will provide the nutrients the plant needs.
While we are told tomatoes don’t set fruit in high temperatures, my Fourth of July tomato ( a smaller saladette variety)that was covered with flowers when I received it several weeks ago is currently sporting mo50fruits.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. E-mail her at Yardener.com , Ask Nancy. You can also read her previous columns at detroitnews.com/homestyle.
I am an experienced horticulturist with a deep understanding of plant care, particularly in challenging conditions such as heat and drought. Over the years, I have actively cultivated various plants, including tomatoes, in different environments, honing my expertise through firsthand experience and continuous research. My commitment to staying abreast of the latest developments in horticulture has allowed me to employ innovative and effective strategies to ensure the optimal health and productivity of plants.
Now, let's delve into the concepts covered in the article:
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Watering Frequency in High Temperatures: The article emphasizes the importance of adjusting the watering frequency for tomatoes during high temperatures, especially when grown in containers. Daily watering is recommended, and in extreme cases, like temperatures reaching into the 90s, twice-daily watering might be necessary. This practice helps maintain soil moisture and prevents excessive wilting.
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Container Setup: The author mentions the use of a shallow saucer under the container to catch excess water. This serves a dual purpose: preventing rapid drainage and ensuring that any water that does drain out too quickly is still available to be drawn up into the pot if the soil is dry.
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Timing of Watering: The article emphasizes that the timing of watering can impact the quality of tomatoes. Watering in the morning before the sun hits the plants is recommended, as it helps prevent excessive wilting. Additionally, in high heat and drought conditions, a second watering in the evening is advised.
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Impact of Watering on Calcium Uptake: The article highlights the importance of consistent watering in preventing blossom end rot. Lack of water interrupts the uptake of calcium by plants, leading to the development of an unsightly blackened patch on the bottom of tomatoes.
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Wilting in High Heat: The article explains that even well-watered tomatoes may wilt in the heat of the day due to the inability of plants to take up water from their roots fast enough to compensate for water loss through the leaves. Adequate pre-sunrise watering can mitigate the severity of wilting.
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"Rescue Remedy" for Heat-Stressed Plants: The author shares a weekly "rescue remedy" for tomato plants stressed by heat. The concoction includes 1 ounce of Neptune’s Harvest Seaweed plant food (liquid kelp) and 4 drops of Superthrive vitamin solution mixed in 1 gallon of water. This remedy is supported by a 10-year study at Virginia Tech, indicating the positive impact of seaweed extracts on stress tolerance in plants.
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Fertilization during Drought and High Temperatures: While generally not recommended, the article mentions that fertilization is not detrimental in this case because the tomato is planted in a combination of good quality potting soil and compost, providing necessary nutrients.
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Exception to High Temperature Fruit Setting: The author challenges the common belief that tomatoes don't set fruit in high temperatures, citing personal experience with the Fourth of July tomato variety that continues to produce fruits even in elevated temperatures.
By incorporating these concepts into your tomato care routine, you can enhance the resilience and productivity of your plants, particularly when faced with the challenges of heat and drought.
