Tomatoes can bounce back easy. Just let them dry a few days and he will be a good as new. Since it is sudden water it will do better than other plants which have begun to root rot from being in standing water for days.
Overwatering generally makes the plant look almost like it's rotting, as in drooping and turning soggy brown. My guess is it is having Nitrogen problems. Any type of vegetable fertilizer you buy at the store should work fine.
Plants may wilt badly when soils are dry, but will revive rapidly when they are watered. A thorough watering once a week during hot, dry weather should be sufficient. Apply water directly to the soil around the base of the plants with a garden or soaker hose.
The good news is that most plants will bounce back between 7-14 days if they're given proper care (which includes rehydration). If this isn't possible because major damage was done or little healthy root system exists then expect about 2 weeks until improvement can be seen.
The faster their soil dries out, the better these plants recover. To speed up the process, place a sheet of paper towel under or around the root ball. After a few hours in the shade and in the open air, the soil will be dry. You can then return the plant to its container.
Is it possible to overcome tomato wilt? The answer to this is, if it's caused by an environmental factor – yes, you can recover your plant. However, if the plant is wilting because of a pathogen, it is unfortunately, almost always necessary to uproot and destroy the plant.
Water correctly: Do not overwater. The first week tomato plants are in the ground, they need water every day, but back off watering after the first week, slowly weaning the plants down to 1 to 1.5 inches of water per week.
To create a solution that prevents and treats disease, add a heaping tablespoon of baking soda, a teaspoon of vegetable oil, and a small amount of mild soap to a gallon of water and spray the tomato plants with this solution. This needs to be reapplied regularly to maintain its efficiency.
Over-watering.
Leaves might yellow and wither, or they could curl.
In the very least, a new central leader will emerge and become the new main stem. Tomatoes are notorious for producing lots of “sucker” stems throughout the season, so you can count on something taking over for the lost main stem. You just need to be patient while the new stem develops.
Some growers prefer to use a high-phosphorus fertilizer, indicated by a larger middle number. You can also keep things simple with a fertilizer especially formulated for tomatoes – usually with a ratio like 3-4-6 or 4-7-10. Most importantly, don't over-fertilize. Too little fertilizer is always better than too much.
Knowing when and how often to water your plants can sometimes feel more like an art than a science, perhaps no more so than for tomatoes. Overwatering tomatoes can lead to yellow and spotted leaves, while underwatering results in wilt and diseased fruit.
It's not unusual for a tomato plant to appear vigorous and thriving one day and then be a limp collection of stems and leaves the next. Wilt is a sign of stress that needs to be addressed quickly to save the plant. Unfortunately, wilt is often not curable, but it can be prevented.
The most distinctive symptoms of Phytophthora root rot are the brown lesions on roots of all sizes. The xylem of the roots above the lesions often turns yellowish or brown. In severe cases, nearly all roots may be girdled or rotted off. Aboveground, infected plants are slow growing and may wilt or die in hot weather.
Soil that contains a lot of sand doesn't hold water well and dries quickly. Because of this, tomato plants growing in sandy soil may need to be watered more often, about every three or four days. Clay soil, on the other hand, holds water well. Plants growing in clay soil usually only need to be watered once a week.
Drip irrigation has emerged as one of the most efficient methods for irrigating tomatoes.
Leaf rolling and cupping
Corn and tomatoes are among many plants that commonly roll their leaves or cup in response to heat. Leaf surface area is minimized, and stomata (microscopic openings in leaves, like pores, that allow movement of moisture and gasses) close. Together, these reduce moisture loss in the plant.
Avoid Overwatering Tomatoes in Summer Weather
Tomato plants need an inch or two of water a week, and a deep soaking is better than a little water every day.
Dry out very wilted plants by removing them from the dirt. Cut off mushy and discolored roots. Replant in dry soil.
Wrap your plant
If you're noticing your potted plant is looking a little overwatered and is already placed in a pot with drainage holes, you might wish to wrap the pot in a dry towel. This can help draw the water out through the holes, and dry the plant faster.