Drooping leaves on Plants

Symptoms

Wilting foliage is the main sign of this problem. Sudden wilting of foliage is listed as a symptom of its own, apart from the fading and dieback that go with low soil moisture. When the cause is inadequate soil moisture, the foliage fades in color and wilts.

The foliage also dies along its margins and tips, and it drops from the plant too early. Overwatering means watering too often or applying too much water in one irrigation, and it can cause wilting. Foliar wilting from overwatering looks the same as wilting from underwatering.

Some wilting leaves resemble drought stress, and the wilting then progresses to death of twigs and small branches. Another pattern is wilting followed by death of the plant, after a bacterial infection spread by feeding insects.

Inspect the root system whenever wilting occurs, to check for root rot rather than assuming drought. Wilting that looks like drought stress is not always caused by drought.

Causes

Water is involved in several causes, starting with inadequate or insufficient soil moisture, which is underwatering. Both too little water and too much water appear on this list. Overwatering or overirrigation is another cause, and so is poor drainage combined with overirrigation.

Prolonged soil saturation, or waterlogging, can cause roots to die. Waterlogged soil also deprives roots of oxygen. Root decay from soil-borne pathogens, known as root rot, is a further cause. Fungus gnat larvae feeding on roots can also lead to drooping.

Excessive light is also listed as a cause. A sudden change in light, temperature, or relative humidity is listed as another. Compacted or pot-bound roots can also be behind the wilting. A toxic chemical poured into the soil is a cause as well.

A systemic bacterial disease in the vascular tissue can also cause drooping. A bacterial infection can also be introduced into the plant by feeding insects such as cucumber beetles.

Diagnosis

Underwatering and overwatering both show up as wilting foliage, so the leaves alone cannot settle which one you have. Check the roots whenever the plant wilts, rather than assuming drought. Root decay from soil-borne pathogens is root rot, and waterlogging that kills roots is also on the list of causes.

Poor drainage combined with overirrigation is one cause on the list, so look at how well the soil drains and how often you water. Compacted or pot-bound roots, a toxic chemical in the soil, and fungus gnat larvae feeding on roots are all on the list of causes.

Think about recent changes in light, temperature, or relative humidity, because a sudden change in any of them is a listed cause. Excessive light is also on the list of causes. If the wilting is followed by death of the plant, a bacterial infection spread by feeding insects is one explanation on the list.

Treatments

Irrigate landscape plants during at least the drought season, as irrigation is required to maintain most urban landscapes. A properly operated irrigation controller can help you avoid both overwatering and underwatering. Inspect the root systems whenever wilting occurs, to check for root rot rather than assuming drought.

To prevent root rot, improve soil aeration and drainage and water at an appropriate frequency. Eliminate standing water around the plant, and let the soil dry as much as possible between waterings. Always use sterile potting soil when you transplant or repot plants.

For new plantings on a poor-drainage site, set the root systems in a raised bed of imported topsoil. Do this rather than trying to redesign an established landscape to raise an existing root system above the old soil line. On a confirmed root-rot site, plant resistant cultivars of the same plant or a different, resistant plant species.

If a plant has a systemic bacterial disease, discard it, since discarding is often the best approach for these diseases. Once a plant is infected with bacterial wilt, pull out and discard the entire plant.

For root rot, chemical control uses fungicide drenches that are taken up by the roots. The active ingredients listed are fosetyl-Al, metalaxyl-m, and pyraclostrobin with boscalid. The product label is the legal instruction, so follow it for the crop and site being treated.

Prevention

Good aeration and drainage in the soil, together with watering at an appropriate frequency, work to prevent root rot. Standing water should not collect around the plant. Letting the soil dry as much as possible between waterings is part of the same advice.

An irrigation controller that is operated properly can keep you from both overwatering and underwatering. Most urban landscapes need irrigation, at least through the drought season. When you transplant or repot, start with sterile potting soil.

On a site with poor drainage, set the roots of a new planting in a raised bed of imported topsoil. Where root rot is confirmed, choose resistant cultivars of the same plant or a different resistant species.

Plants most often affected

Squash, pumpkin and melon are the plants named as hosts for this problem. Injury by squash bugs is limited to squash, pumpkin, melon, and other plants in the cucurbit family. Wilting followed by plant death can come from a bacterial infection that feeding insects such as cucumber beetles introduce.

No plant page in this build records this problem yet.