Plants wilt when roots are unable to supply sufficient moisture to the stems and leaves. Wilting for short periods of time does not harm plants. Sometimes a plant wilts on a hot day because moisture is evaporating from the leaves faster than the roots can take it up.
On a hot, dry day (or after several days with no rain or watering), transpiration causes more water to be lost than is coming in, and the water balance within the plant can get thrown off. The dehydrated collapsing cells in the leaves and stems can no longer remain erect, and the plant begins to wilt.
Wilting can be prevented by shading the plant on hot days. Some near dead plants can be revived by first cutting back the dead leaves, lightly watering and then placing a water proof barrier over them such as a plastic bottle.
Whether it's outdoors or in an office, plants wilt in most situations because they've simply run out of available water. Water is constantly moving in a plant from the soil, into the roots up through the stems and out to the leaves.
Lack of light. If your plant is not getting enough sun it will wilt because it can't absorb enough light to feed itself. Solution: Try moving the plant somewhere a little brighter. Be gentle, so just shift it a little closer to a window.
1. If a plant is overwatered, it will likely develop yellow or brown limp, droopy leaves as opposed to dry, crispy leaves (which are a sign of too little water). Wilting leaves combined with wet soil usually mean that root rot has set in and the roots can no longer absorb water. 2.
Wilting can be caused by drought or waterlogged soil
Sometimes a plant wilts on a hot day because moisture is evaporating from the leaves faster than the roots can take it up. If there is ample soil moisture, the plant will absorb water in the evening to restore turgor to the stems and leaves.
Treatment and control
If wilting is due to a lack of water at the roots, carefully re-water the soil or compost. Overwatering and flooding the growing medium can cause further root damage, which then leads to further wilting. If it is due to damage to the stems, prune out all those parts that are affected.
Over-watering.
Overdoing your watering can have a similar effect to underwatering. You may also find your plants produce an excess of foliage but few tomatoes. Leaves might yellow and wither, or they could curl.
Wilted greens such as lettuce, kale, and chard can be revived with a cold water bath. Before composting leafy greens that seem to have lost their pep, take a few simple steps to bring them back to life. For lettuce: cut the base about 1/2", or separate leaves from base entirely.
Leaves may wilt in response to poor drainage, high root temperatures, too much fertilizer, pests and pathogens, spiraling roots that are constricting themselves, and/or compacted soils. Several of those issues are a problem for the plant because of poor oxygen availability in the soil, which can lead to root hypoxia.
During spring and summer in Southern California, she suggests drip watering three times a week for 18 minutes, then adjusting from there if the soil is too wet or dry. Don't know how to tell? Stick your finger in the soil. If it's consistently moist 2 inches down, your plants are fine.
If you have a wilting plant the first thing you want to do is give it a thorough watering. You can accomplish this by putting your plant in the sink, or adding watering for anywhere from 3 to 8 minutes (depending on pot size and specific plant/soil requirements), letting the water completely drain out of the bottom.
Curled leaves are usually a sign that they've been exposed to either too much heat or too much light. Or both! Plants obviously need both of these to survive and thrive. But every plant type is different and each one requires varying amounts.
Can your wilted plant be saved? It depends on why your plant is wilting. Different causes require different responses. If you've under watered your plant or have extremely low humidity, you can add water more and/or raise the humidity level around the plant.
Leaf curl disease shows up in spring, does the damage, and then disappears (until next spring). If your trees were infected last spring, they should have completely recovered by mid to late summer. They usually grow lots of healthy new leaves (like the photo below).
“If your plant's leaves are looking wilted and yellow, the problem is likely overwatering,” Cheshire explains. “Overwatered leaves will have a very soft, floppy look, because they're waterlogged.” Another, non-water-related reason why your plant might be drooping is because it's not getting enough light.
Overwatered plants can sometimes recover on their own, but it depends on the plant and the extent of the overwatering. If the roots have rotted, the plant will likely not recover. However, if the overwatering has only caused the leaves to wilt, the plant may be able to bounce back.
If your plant is wilting, try giving it some water and see if it perks up. Sometimes it's as easy as that. Most plants leaves will begin to wilt when they need watered. As long as the leaves have not become crunchy, they will perk up within a few hours.
The plant hormone that causes wilting of leaves is Abscisic Acid.
Once a plant is infected, there is no cure, and it must be removed to prevent the spread of the disease.
2. Wilting: Paradoxically, overwatered plants often wilt, much like underwatered plants. The difference is that overwatered plants feel soft and mushy because their roots are rotting, inhibiting water uptake.
Leaves with slight damage can be trimmed back, especially if it's the leaf tip. If you prefer to remove the whole dying leaf, that's fine too. Trimming back dying foliage will encourage new growth. However, you also have the option to leave dead leaves on the plant as long as there's not an insect infestation.