Overwatering is a common problem that all gardeners new and old are likely to be guilty of at some point. More is not always better when it comes to watering and overwatering can kill plants.
Damage does not happen overnight and your plants will show you when they are unhappy. You should be able to spot the signs that you are overwatering outdoor plants. They will show symptoms such as yellow leaves, wilting, or a lack of new growth, while even the color of the surrounding soil can be an indicator of trouble.
When judging when to water the plants, remember to check the current soil moisture. This may already be enough and adding more unnecessarily could endanger the health of your plants.
Watch plants closely for signs of watering problems
(Image credit: Getty/Betsie van der Meer)
How do you know if you are overwatering your plants?
Overwatering is a common watering mistake in the garden and the result is that the roots cannot absorb oxygen in saturated soil and this can cause the whole plant to rot. Although you cannot see root rot below the surface, the presence of certain signs above ground can be an indicator of this potentially devastating problem.
Zahid Adnan, experienced gardener and founder of The Plant Bible, says it’s “important to understand and recognize the signs of overwatering outdoor plants” so that you can intervene and help maintain plant vitality.
He adds, “Recognizing the signs of overwatering outdoor plants is crucial to maintaining their health and preventing potential damage. By monitoring your plants closely, you can take timely action to correct overwatering problems.
We take a closer look at six signs of overwatering, so you know what to look out for if your plants are showing symptoms of overwatering.
Zahid is a renowned figure in the gardening industry, with extensive experience and hard-earned skills in horticulture. As founder and publisher of ThePlantBible.com, he provides top-notch content and professional advice to fellow gardening enthusiasts daily. In addition to his work, Zahid manages 10 hectares of agricultural land and maintains an exceptional garden in his own backyard.
Wilting leaves can be a sign of overwatering outdoor plants
(Image credit: Alamy/Madelynn Fangio)
1. Withering
It may seem counterintuitive, but wilting can be one of the first signs of overwatering. This might be confusing for some gardeners, as wilting plants are more often seen as a sign of under-watering. This has the potential for people to add more water to wilting plants that are already overwatered, especially when watering plants in hot weather. Wilting can occur because too much water will limit oxygen availability to the roots, essentially smothering them so they can’t take up water. The plant will become limp and wilt accordingly.
At the first sign of wilting, check the moisture levels in the soil about an inch deep by digging your fingers into the soil or using a moisture meter. If it seems very damp and there is a lot of moisture, move away and let the soil dry out before watering again. This should allow the roots to recover and then in future always allow the soil to dry out between waterings.
Checking levels below the surface is essential, whether it’s plants in the ground or watering plants in containers. In pots, you can water the plants from below to help control the amount of water absorbed by the soil.
Lack of oxygen due to waterlogged soil causes leaves to wilt
(Image credit: Alamy/Kathy deWitt)
2. Yellowed leaves
Yellowing leaves can be a harbinger of a plethora of problems, including lack of nutrients, pests, disease, and overwatering. The leaves will begin to lose their green color and slowly turn yellow, while browning may occur from the tips. The lower leaves may begin to drop and the choking roots cannot provide the water and nutrients the plant needs to thrive.
Yellow leaves can affect any plant, from roses with yellow leaves to tomatoes suffering from yellow leaves. The best tactic is to recheck moisture levels in the soil where the eyes cannot see. If it seems too wet, too much water could be the cause. Then you repeat the suggestion above and wait for the soil to dry out. If the soil doesn’t seem too wet, the yellow leaves could be a harbinger of something else.
Overwatering can smother roots, causing leaves to yellow
(Image credit: Getty/Pavel Rodimov)
3. Stunting
Stunted growth basically means that the plant is not growing as one would expect, it remains small and underdeveloped with a lack of new growth. Stunted growth is often seen with yellowing leaves as classic signs of overwatering.
Diana Cox, experienced home and garden consultant and creative force behind The Gardening Talk, explains: “Overwatering leads to oxygen starvation in the roots, which hinders cell division and slows plant metabolism, causing growth retardation. To counter this, water plants less frequently and improve soil aeration and drainage.
“By implementing these techniques, I have observed significant improvements in plant growth after addressing the overwatering issues.”
Diana started her website as a way to help newcomers to the world of gardening and plant care. She has been growing plants since she was little and started documenting her gardening experience a few years ago.
Plants may not grow as vigorously as expected if overwatered
(Image credit: Alamy/Jirakan Jiherb)
4. Leaf fall
Leaf drop, where foliage falls prematurely from the plant, is a sign of a stressed plant and over and under watering can be the cause. However, most of the time it is not out of the blue, there are usually early signs of yellowing or browning of the leaves before they drop. The plant loses its leaves in response to stress caused by a weakened root system. Overwatering can cause waterlogged roots which begin to rot and leaf drop will occur as a result.
Try to check soil moisture levels at the first sign of yellow leaves, but do so definitely after the leaves have fallen. If the soil doesn’t seem excessively wet and overwatering may not be the case, assess the plants for pests or diseases that may be the cause.
Overwatering can cause the leaves to turn yellow and fall off the plant.
(Image credit: Alamy/Armen Gharibyan)
5. Edema
Edema, also called edema, is an unusual sign that your plant has been overwatered. It manifests as bumps, blisters or lesions on the foliage. Contributing factors are that the plant has taken up more water than it needs. The cells are then filled with water, filling up and swelling until they burst.
Some types of plants are more sensitive than others, such as camellias, fuchsias, pelargoniums or succulent and edible plants, especially peppers and tomatoes. This can be more of a problem in high humidity U.S. hardiness zones.
The best way to combat edema is to check soil moisture levels and, if possible, add more organic matter like compost or leaf mold, to help improve soil drainage. Do not remove affected leaves as this may increase the problem throughout the plant.
Edema is caused by plant cells that burst due to too much water
(Image credit: Alamy/Nigel Cattlin)
6. Green soil
While the plants themselves show signs of overwatering, so does the soil around them. If the soil takes on shades of green, it is a sign that it has been overwatered.
Green soil is a sign of algae or moss growth, which thrives in moist conditions. Although algae on the ground does not harm established plants, it can affect the growth of young plants and is also unsightly on flower beds and borders.
Regular removal of clods or algae or moss is recommended, as well as reducing the regularity of watering and adding drainage to the bed to prevent the soil from becoming compacted and waterlogged.
FAQs
Can a plant recover from overwatering?
Yes, plants can recover from overwatering provided the warning signs have been spotted and action taken. This will depend on the severity of the overwatering and its duration. For example, a withered plant or a plant with a few yellow leaves is easily salvageable, but if severe root rot has occurred due to waterlogging, it may be too late.
It is crucial to know your plants to adjust the frequency and amount of watering according to the needs of each specific plant. Let the soil dry out completely after a plant has been overwatered, before adding more moisture. Adding organic matter to help improve drainage can help prevent a bed from becoming waterlogged and prevent plants from remaining in very humid conditions.
Vigilance is obviously essential when it comes to taking care of your plants. It’s not just with watering that you have to watch closely for symptoms, it’s the same with pests and diseases. Know your plants, monitor your plants and do your research. Learning everything about your plants, including how much water they need, will help you maintain a good watering regimen which should help avoid potential overwatering issues.