Water wisely

By Heather Kirk-Ballard

LSU AgCenter Horticulturist

One of the most common causes of plant death is water — more specifically, too much or too little water.

You might be surprised to learn it’s sometimes hard to tell the difference. Watering correctly is a fundamental aspect of caring for both indoor and outdoor plants and trees. Providing the right amount of water is crucial for their health and vitality, impacting everything from root development to overall growth and resilience.

Underwatering and overwatering can lead to severe consequences, manifesting in similar distress signals such as wilting, yellowing and even death. Understanding the precise watering needs of each plant species and considering factors like soil type, climate and growth stage is essential for creating an optimal growing environment.

Proper watering practices not only ensure the survival of plants but also enhance their beauty and productivity, making this knowledge indispensable for every gardener and plant enthusiast.

When plants appear fatally ill or dead, one common symptom is wilted, weeping foliage that transitions from green to yellow and often crispy brown. Let’s investigate the potential causes.

To check for underwatering symptoms, we start with the soil. Check beyond the surface by inserting a finger a couple of inches into the soil. In addition, you can inspect the roots. For potted plants, remove the plant from the pot and examine the roots. Healthy roots are firm and white. Another great test is the flexibility test. Bend a stem; if it snaps, it’s dry. If it springs back, it’s OK.

One last test is the scratch test. To perform this test, lightly scratch a tender stem. Green beneath the bark or surface indicates the plant is still alive.

If these signs point to dehydration, water the plant thoroughly and establish a regular watering schedule based on the plant’s needs, environmental conditions and light exposure. In the heat of the summer, plants are transpiring and losing a great deal of water, so check potted plants several times a week.

Did you know that the symptoms of underwatering can look just like a plant that has been overwatered? Yellowing leaves, wilting, leaf drop and stunted growth are shared symptoms. Overwatering can also produce soft stems, brown or black roots, mold or algae, lesions on the leaves and stunted growth.

The first step is to check for standing water around the plant. Next, check the soil with your finger in the soil; if it’s excessively wet, this could be the issue.

Next, check the condition of the roots. Check for brown, soft roots and any foul odor indicating rot. You can try the stem flexibility and scratch tests to check for overwatering too. A limp stem and dark discoloration under the bark confirm overwatering.

Excess water in the soil can suffocate roots, leading to root rot caused by fungal infections. Saturated soil fills air pockets, preventing roots from absorbing oxygen, effectively drowning the plant. In addition, overwatering can wash away essential nutrients from the soil, making them unavailable to the plant. This leads to nutrient deficiencies. Excess moisture can weaken the structural integrity of the plant, making it more susceptible to diseases and pests.

Achieving a balance between wet and dry soil is crucial. Ensure adequate drainage and appropriate watering schedules. Healthy roots are fundamental for vigorous plants. For persistent issues, consult your local AgCenter office for expert diagnosis and treatment recommendations.

Remember, maintaining optimal root health is key to preventing plant ailments.

Plant with green foliage.

Drooping leaves on this azalea show symptoms of root rot. Photo by Page Langlois/LSU AgCenter

Roots of a plant.

An older potted Turk’s cap has a mature, larger, healthy and white root system. Photo by Heather Kirk-Ballard/LSU AgCenter

Trees with wilted leaves

A major sign of drought stress is the overall wilting of leaves. As underwatering continues, leaves will eventually drop. Photo by Heather Kirk-Ballard/LSU AgCenter

6/20/2024 1:55:21 PM
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