Both overwatering and underwatering plants can cause serious issues, but which one is ultimately worse for your plants? There are a few factors to consider when determining whether too much water or too little does more harm.
What Causes Overwatering?
Overwatering occurs when the soil remains saturated for too long. This can happen for a few reasons:
- Watering too frequently – Plants take time to use up water in the soil. Watering again before the soil has had time to dry out will lead to oversaturation.
- Using too much water at once – Applying an excessive amount of water in one watering can flood the soil.
- Poor drainage – If the soil or container does not drain well, water will remain rather than percolating down through.
- Cool weather – Plants take up less water when temperatures are low. Watering as much in cool weather as in warm leads to overwatering.
Signs of Overwatering
How can you tell if you’ve been overwatering your plants? Here are some common signs:
- Wilting leaves – Although counterintuitive, wilting can happen from both under and overwatering. The leaves will be limp and lifeless.
- Leaf drop – Lower leaves turn yellow and drop from the plant.
- Mold growth – Excess moisture encourages mold growth on top of the soil or on the plant’s stems and leaves.
- Soft, mushy stems or leaves – With too much water, plant tissues easily decay and turn to mush.
- Slow growth – Too much moisture prevents oxygen from reaching roots and slows growth.
- Spongy feeling soil – Saturated soil feels airy and spongy when pressed.
- Algae growth – Excess water leads to green algae growth on top of soil.
- Roots rotting – Roots are most prone to rotting from overwatering.
What Problems Does Overwatering Cause?
Excess moisture puts plants under a lot of stress and leads to a variety of issues:
- Root rot – One of the most common issues, root rot occurs when roots are deprived of oxygen for too long. Rot can begin with just a few roots or take over the entire root system.
- Fungal diseases – Too much moisture allows fungal spores to germinate and attack your plant’s leaves, stems, crown, or roots.
- Bacteria growth – Pathogens like bacteria thrive in wet conditions and can cause illnesses like bacterial leaf spot.
- Nutrient deficiencies – Overly wet soil makes it harder for roots to take up nutrients. Deficiencies result.
- Pest problems – Some pests like fungus gnats flourish in damp surroundings.
- Lower oxygen levels – Waterlogged soil contains less air space for oxygen circulation to roots.
- Plant decline & death – If left unchecked, the stresses above weaken plants until they decline and die.
What Causes Underwatering?
Underwatering is simply failing to water plants frequently enough. Common causes include:
- Forgetting or neglecting to water at all
- Allowing soil to completely dry out between waterings
- Not watering thoroughly enough to moisten entire root zone
- Relying only on rain to water in dry weather
- Having soil that drains very rapidly
- Keeping plants in overly small containers
- Having incorrect growing conditions – high heat, wind, low humidity
Signs of Underwatering
The most obvious sign is dry, cracked soil. But other symptoms include:
- Wilting or drooping leaves and stems
- Leaves turning yellow or brown
- Leaf edges or tips turning brown
- Leaves feeling crispy or brittle
- Stunted growth
- Blossoms or buds dropping
- Bare, dead patches on plants
- Plant death
What Problems Does Underwatering Cause?
Allowing plants to dry out too much leads to:
- Stunted growth – Without enough moisture, plants can’t perform photosynthesis or use nutrients effectively.
- Decline & death – As plants become more severely dehydrated, they shed leaves and eventually die.
- Leaf scorch – Dry air and soil cause leaf tips and margins to turn brown.
- Wilt diseases – Bacteria like Verticillium wilt infect stressed plants more readily.
- Pest infestations – Stressed, dehydrated plants are more appealing to pests.
- Nutrient deficiencies – Plants can’t take up nutrients if soil is too dry.
- Root damage – Lack of water literally desiccates and destroys roots.
Overwatering vs Underwatering: Which is Worse?
There are arguments for both over and underwatering being more detrimental to plants. Here are the key points:
Overwatering May be Worse Because:
- It more directly promotes rot, fungal diseases, and pathogens.
- Saturated soil is very low in oxygen, which plants desperately need.
- It is harder to diagnose and correct than underwatering.
- Plants recover more easily from dehydration than from saturated, rotten roots.
Underwatering May be Worse Because:
- Totally desiccated plants usually can’t be revived and death happens fast.
- It stresses the entire plant, not just roots.
- If neglected long enough, the damage cannot be undone.
- It allows problems like pests and disease to take hold.
Overall, both extremes can be deadly for plants if allowed to persist. However, overwatering may ultimately lead to more disease and fungal problems, making it harder for plants to recover. Some dehydration can be reversed if caught early enough, but there is a tipping point after which underwatering does become fatal.
How to Find the Right Watering Balance
The ideal approach is to find that perfect middle ground between overwatering and underwatering. Here are some tips:
- Water only when top few inches of soil are dry.
- Water thoroughly until it runs from drainage holes.
- Adjust frequency for plant type, season, and conditions.
- Allow soil to partly dry between waterings.
- Use soil amendments to improve drainage in heavy soils.
- Water in morning so plants dry during day.
- Never let pots sit in water.
- Ensure containers have drainage holes.
- Group plants by water needs.
- Feel soil to gauge moisture rather than on fixed schedule.
Finding this balance takes experience and observation. There’s no set formula, since each plant and situation is unique. Learn your plants’ needs and stick your finger in the soil regularly to guide your watering schedule.
Both over and underwatering cause significant harm, but overwatering is generally riskier in the long run. Its effects are less obvious yet foster dangerous fungal and bacterial growths. However, allowing plants to completely dry out past permanent wilting point is also devastating and impossible to recover from. The keys are learning your plants’ preferences, watering only as needed, ensuring drainage, and regularly checking soil moisture. Finding that perfect middle ground takes practice, but will result in thriving, healthy plants.