Horticultural Myths – Wilting Leaves

Myth

One of the best indicators of a plant needing water is when the leaves on the plant wilt. This indicates that the soil moisture level is low and needs replenishing.

Truth

Leaves on a plant can wilt for a variety of reasons. Those reasons can include:

  • Damage from insects, pests, or rodents
  • Fungal or bacterial issues
  • Girdling roots that restrict or damage other roots
  • Large amounts of salts from fertilization, existing soil, or water source
  • Root damage from excessive heat or freezing temperatures (especially common in containers)
  • Lack of oxygen in the root system from overwatering
  • Lack of water in the soil

Using wilted leaves as an indicator for a need to water can sometimes be accurate. The real problem arises when lack of water is not the issue. Overwatering then leads to a lack of oxygen in the soil which is known as root rot, or more properly, root anoxia. Root rot is the most common cause for death in plants. This is especially a huge problem in compacted soil and soil with layers of hardpan or caliche.

Once the roots experience a lack of oxygen they shut down and stop taking up water. This leads to the leaves lacking water, therefore they wilt as a sign of stress from drought. The difference is that too much water in the roots is causing the issue. Both overwatering and underwatering can cause leaf wilt.

In order to avoid this common mistake be sure to assess the soil conditions before choosing to water if your plant has wilted leaves. If the soil is still wet, consider aerating the soil near the drip line or root zone. Click here for more information about how to correctly water your plants.