Lavender (Lavandula spp.) is a drought-tolerant Mediterranean plant that thrives in well-drained soil and prefers infrequent but deep watering. Overwatering or underwatering can disrupt its growth, leading to visible stress signs. Understanding these signs from the plant's perspective helps maintain optimal health.
Overwatering is more harmful to lavender than underwatering due to its susceptibility to root rot. Here are key symptoms:
The lower leaves turn yellow or pale green as roots suffocate from excess moisture, impairing nutrient uptake. This contrasts with healthy lavender's silvery-green foliage.
Paradoxically, overwatered lavender may wilt even when soil is damp. Soggy roots cannot absorb oxygen, causing cellular collapse in stems and leaves.
Black, mushy roots with a foul odor indicate fungal infections like Phytophthora. The plant's vascular system fails, leading to stunted growth or sudden death.
White powdery mildew or gray mold (Botrytis) on leaves signals excessive humidity and poor air circulation from overwatering.
While lavender tolerates dry spells, prolonged dehydration stresses the plant. Key symptoms include:
Leaves dry out from the tips inward, becoming brittle and brown as the plant conserves water by sacrificing older foliage.
New shoots appear shriveled or fail to develop, and flowering diminishes. The plant prioritizes survival over reproduction.
In containers, severely dry soil contracts, creating gaps between the soil and pot. Roots lose contact with moisture reserves.
Leaves curl inward to reduce surface area and minimize water loss through transpiration, a classic drought response.
Lavender's native arid habitat equips it with adaptations:
Mature lavender develops long taproots to access groundwater, making it resilient to short dry periods but vulnerable to stagnant moisture.
Foliage minimizes water loss via transpiration. Overwatering disrupts this adaptation by forcing excessive turgor pressure in cells.
Key distinctions include:
Overwatered soil remains soggy for days; underwatered soil is dry and crumbly even below the surface.
Overwatered leaves are soft and yellow; underwatered leaves are dry and crispy.
Healthy roots are white and firm. Brown, slimy roots indicate overwatering, while brittle, shriveled roots suggest dehydration.
