Proper watering can make or break your garden’s success. Whether growing indoors in pots or outside in the soil, finding a balance between overwatering and underwatering isn’t always easy. The right moisture level depends on the plant species, soil conditions, humidity, temperature, rainfall, and container or bed style.
While overwatering is a common problem, underwatering can be equally as detrimental to plant health. Let’s dig into the early signs of drought stress and how to save your plants from potential damage due to underwatering.
How Do You Know if a Plant is Underwatered?
Inadequate watering for potted plants is often indicated by the soil receding from the edges of the container.
Drought stress usually manifests as wilted, yellowing, crispy, or curled leaves, leaf drops, and dry or cracked soil. If a potted plant isn’t getting enough water, you’ll often notice the soil pulling away from the container edges. A thirsty plant in the ground may drop its flower buds, reduce its fruit set, and become infested by pests.
Water your plant immediately with a generous soak, then allow it to soak in the soil and repeat again the following day. Potted plants can be placed in a shallow dish of water to absorb moisture through the pot’s drainage hole. Alternatively, you can remove a plant from the soil, soak its roots in water, and transplant it into freshly moistened soil rich in compost.
Overwatering vs. Underwatering
Hydrate your plant and monitor it daily for at least a week.
While overwatered and underwatered plants may look wilted and yellow, the underwatered plant will have noticeably brittle or crispy leaves, stems, and roots. Overwatered plants tend to be soggy, wilted, soft, and limp.
To remedy underwatering, hydrate your plant and check it daily for at least a week. If the soil has dried out significantly, bringing your plant back to life often takes much more water than you think. Hydrophobic (water-repellant) materials like clay, coconut coir, or peat moss can take a long time to rehydrate once completely dry.
11 Signs of Underwatering and Drought
Dry things tend to shrivel up. Whether you’re dealing with drought-stricken perennials, underwatered perennials, or thirsty houseplants, these universal signs of water stress are noticeable across almost every family of plants.
1. Wilting Leaves
Wilting is the typical reaction to drought stress in plants.
The most common response to drought stress is wilting. When a plant isn’t getting enough water, the cells lose turgidity and shrivel up, causing the leaves and stems to droop.
The top leaves usually wilt and show signs of drought first. The plant may look weak, and the leaves appear to shrink in size. In contrast, overwatered plants tend to wilt from the bottom up, and the leaves have a more soggy, limp appearance.
2. Dry, Cracked Soil
Sandy soil appears excessively dry, making it highly vulnerable to drought due to its poor water retention abilities.
Dried-out plants almost always have cracked, dusty, or dehydrated soil around their root zone. If you put your finger into the soil and it feels dry, it’s a clear sign that your plant is thirsty. The soil won’t stick to your skin and may even come out with a chalky residue.
Clay soil is particularly prone to cracking and tends to follow patterns of shrinking or swelling. In drought conditions, clay particles shrivel and pull apart, often causing big visible fissures in the land.
On the other hand, sandy soil will appear excessively dry. Sandy soil is the most prone to drought because the large particles have bigger pores between them. This is excellent for drainage (think of sand on the beach) but not so great for retaining water. Below, we’ll describe some ways to improve moisture retention in your soil to protect your plants from drought stress.
3. Yellowing Leaves, Especially With Brown Edges
If you notice yellowing combined with browning leaf edges, it likely indicates insufficient watering.
When a plant lacks water, it has difficulty transporting nutrients to its leaves. This causes leaf discoloration due to a lack of chlorophyll, the key pigment used in photosynthesis.
Yellowing leaves are a near-universal sign of plant stress. However, when the yellowing appears alongside brown leaf edges, it’s probably a symptom of underwatering. If the yellow color appears in blotches or ringed spots, you are more likely to deal with a plant disease like blight or one of the leaf spot pathogens.
Look for Multiple Symptoms
Before adding more water to your plant, take a moment to reevaluate your diagnosis.
It’s important to look for multiple symptoms when identifying drought stress. Yellow leaves alone could be linked to overwatering, nutrient deficiencies, soil compaction, the diseases described above, or the changing seasons.
But yellow leaves with brown, crispy edges and dry, cracked soil around the base are a sure sign of underwatering. Double-check your diagnosis before pouring water on your plant.
4. Crispy or Curling Leaf Margins
Encouraging the plant to channel its energy into revitalizing its roots and growing new leaves is a common recommendation.
If the edges of a plant are curling inward, shriveling up, and feel crispy in texture, it’s a sign of water stress. The plant is trying to conserve moisture by reducing the leaf surface area. As the leaves curl, less of the plant is vulnerable to the drying effects of sunlight and air.
An extremely underwatered plant may crumble when you touch it. As the leaves dehydrate in hot, dry conditions, the cells eventually die and cannot be revitalized, no matter how much water you give the plant. Sometimes, the best course of action is to remove the dehydrated leaves and encourage your plant to channel its energy into rehydrating its roots and growing new foliage.
5. Leaf Drop
Always be vigilant of fallen leaves and other signs of underwatering.
In severe cases of drought or underwatering, a plant will no longer be able to support all of its foliage. It may start to shed and drop withered leaves as a last-ditch effort to conserve energy and try to survive. This reduces water loss through transpiration from stomatal pores in leaf surfaces.
Leaf drop can also occur due to a lack of sunlight, overly hot or cold weather, and overwatering. It can also just be a sign of the end of the season (hence, autumn leaves). So, always identify this symptom alongside other indicators of underwatering.
Don’t Use Dehydrated Leaves as Mulch
Dried deciduous leaf mold or straw make excellent mulch options to prevent soil from drying out.
Regardless of the cause, cleaning up any dropped leaves is important so they don’t become a harbor for disease or pests. Dried deciduous leaf mold or straw are great sources of mulch to prevent soil drying, but the dropped leaves from a sick plant sometimes carry more risks than benefits.
Remove them, water deeply, and mulch the root zone with a clean, disease-free mulch to help the plant recover in protected soil.
6. Stunted or Slow Growth
Prolonged dryness during a heatwave can significantly impede or even completely halt a plant’s development.
Everyone moves slower when they are thirsty. This is why athletes facing dehydration often get dizzy or are forced to rest for a long while. If your plant seems to be staying the same size or growing agonizingly slowly, it may not have enough water to support the formation of new roots, stems, and leaves.
This is particularly noticeable when crops like fast-growing radishes or zucchini suddenly stall their development. They may have doubled or tripled in size during their first weeks of growth, but if they become dried out during a heat wave, their growth may dramatically slow or stop entirely.
Other Causes of Stunting
Relying solely on stunted growth as the sole indicator for diagnosing plant issues is not advisable.
As always, don’t rely on stunting as your only diagnosis factor. Plants also become stunted due to nutrient deficiencies, soil compaction, diseases, extreme weather, and an end to their lifecycle.
For example, a lavender bush may have been bursting with fresh new growth and flowers throughout the spring, then slow its growth in the summer. This is likely due to the shifts in daylight and the plant’s natural life cycle rather than underwatering (lavender is very drought-resistant).
On the other hand, if you had a kale plant growing vigorously in a cell tray and then transplanted it into heavy clay soil, the kale may become stunted and take a long time to recover after transplanting. This stunting can be due to shock, poor soil, and under or overwatering.
7. Brittle, Dry Roots
Be sure to avoid any abrupt tearing or yanking of the roots from the ground.
If you flip over a potted plant or dig up your in-ground plant, you will likely find the roots brittle and breakable. Healthy roots should be pliable and firm, but a severely dehydrated plant loses all of its moisture in the root cells, making it even more difficult to recover and uptake water again.
Never be afraid to gently dig up a plant to better diagnose it. Most every plant can be transplanted or re-potted to recover after root disturbance. The key is to loosely dig around the circumference of the root zone and gently lift it from the soil. Avoid ripping or yanking the roots out of the ground. Instead, use a digging fork or fingertips to coax the roots free.
Dehydration vs. Root Rot
Differentiating between overwatering and underwatering can be determined by examining the roots.
The roots are an important means of differentiating between overwatering and underwatering. If your plant has yellow, wilted leaves and stunted growth, you may wonder if it’s getting too much water or too little. In addition to these symptoms, let’s say the top few inches of soil feel fairly moist. You might be very confused about what’s going on.
When you pull the plant up, you may find that the roots are actually super dried out. If you weren’t watering deeply, hydrophobic materials like peat moss and coco coir may be repelling water from penetrating the lower layers. On the other hand, if the roots are soggy and mushy and the lower soil is waterlogged, you may be facing root rot.
Whether the roots are shriveled and dry, or soggy and rotten, the plant cannot properly uptake water. Since you’ve already uprooted it, you might as well prune away damaged parts of the roots (using sanitized pruners) and soak them in a rehydration solution of water and diluted kelp. You can leave the roots submerged in a bowl of water for 12-24 hours, ensuring the roots aren’t exposed to direct sunlight. Then, re-pot the plant in fresh soil with plenty of organic matter.
8. Soil Pulling Away from Pot Edges
Underwatering in potted plants often manifests as soil receding from the container’s edges.
Potted plants usually display a very noticeable sign of underwatering: the soil seems to pull away from the edges of the container. This happens due to shrinking soil particles. As the soil shrivels up and reduces in size, there will be an obvious gap between the dirt surface and the pot edges.
This large gap can make it extra challenging to rehydrate the plant. You may need to use a fork or your fingers to loosen the dry soil gently and spread it back toward the edges before liberally resoaking the plant.
This symptom may also appear in raised garden beds, so look closely around the edges where the soil typically meets the metal or wood walls of the raised bed.
9. Pest Infestation
Ensure your plant’s well-being by addressing pest infestations and underwatering at the same time.
Underwatered plants become very stressed and vulnerable to attack by insect pests. Aphids, spider mites, and mealybugs are especially quick to jump onto a thirsty plant. As plants weaken due to a lack of moisture and nutrients, their natural defenses weaken as well.
Natural protective mechanisms include thick leaf cuticles, strong aromas, or trichomes (tiny leaf appendages that protect against feeding). Without adequate water, the plant no longer has the energy to fuel these defenses, which means its guard is down and more susceptible to pest attack.
Be sure to address pest infestations and underwatering simultaneously to ensure your plant can recover. A heavy blast of water can dislodge sap-sucking pests, and diluted neem oil can repel them while the leaves bounce back from drought.
10. Dropped Flower Buds
Deadheading is the practice of removing withered flowers to redirect the plant’s energy towards new blooms.
Drought-stricken plants typically drop their flower buds prematurely as a survival mechanism. You may notice fallen flower petals near the base of the plant. This is often one of the earliest signs of underwatering. The plant sacrifices its reproductive organs (flowers) so it can redirect energy into survival. If any living thing doesn’t have the water or food it needs to live, it has little chance of reproducing.
However, remember that some plants drop their flowers when the bloom cycle is complete or the flower has been pollinated. For example, hydrangea blooms usually last for several weeks and then shrivel and drop so the shrub can produce new flowers. Deadheading is a practice of removing withered flowers so the plant puts energy toward new ones.
Similarly, squash plants drop their male flowers once the pollen has been spread. Fallen blossoms don’t always mean the plant is underwatered, so double-check that this symptom appears with others listed above.
11. Reduced Fruitset
When plants experience severe water stress, they typically cease fruit or seed production.
Hard times call for extreme measures. Plants that become extremely stressed from lack of water usually stop producing fruits or seeds. For example, underwatered tomatoes usually drop their flowers (preventing new fruit production) and stop putting energy toward ripening fruit. Blossom end rot (rotten tomato “butts”) may develop due to water stress.
If your plant is no longer producing new flowers and fruits, don’t panic! It will likely return to fruit production once it has enough water in its soil. But lack of fruitset can also be correlated with nutrient deficiencies, temperature fluctuations, and reduced day length at the beginning or end of the season.
How to Fix and Prevent Underwatering
Fortunately, underwatering is easy to fix and prevent with a little planning and observation. Most plants can recover from drought with very deep watering, improved soil, and a consistent irrigation schedule.
1. Water Thoroughly
To ensure proper irrigation, water should be applied deeply and evenly.
The biggest mistake gardeners make when watering is rushing the process. If you only dump a small amount of water on your soil, it doesn’t actually penetrate the root zone for long-lasting moisture.
When you irrigate, make sure you water deeply and evenly. You may need to hold the hose or watering can longer than you think, slowly moving it around the entire root zone so the water doesn’t just blast on one area.
Allow the water to thoroughly moisten the soil until it drains from the bottom of the pot or starts to soak the soil surface. Depending on the soil depth, a generous soak should moisten the top 6-12” of soil.
Deep Watering Requires Less Frequency
Watering thoroughly allows roots to access deeper soil moisture, reducing the need for frequent watering.
When you water thoroughly, you don’t have to water as often because the roots can access moisture deeper in the soil.
Many plants like pothos, aloe vera, lavender, rosemary, and many perennial shrubs prefer deep, infrequent watering rather than lots of light watering. In other words, they don’t mind drying out a bit between watering sessions as long as their next irrigation session is very deep and thorough.
On the other hand, most vegetables like tomatoes, peppers, melons, squash, lettuce, and basil enjoy consistently moist conditions. They don’t want their soil to dry out, but they shouldn’t sit in soggy conditions either.
Either way, you want to avoid shallow watering, which only soaks the upper inches of soil and can lead to dry, hydrophobic soil conditions in the lower layers.
2. Improve Soil Moisture Retention
High-quality compost binds soil particles and increases water retention when needed by plant roots.
Compost, rotten manure, and decomposing organic matter are key for improving soil moisture retention. If your soil tends to dry out really quickly, it’s probably a sign of low organic matter. Amendments are the easiest way to improve the “soil sponge” so that it holds onto moisture longer.
High-quality compost holds soil particles together and creates more space for water to linger when plant roots need it. At the same time, compost improves soil drainage so the roots don’t get waterlogged or rotten.
3. Use Mulch to Prevent Evaporation
Mulch plays a crucial role in decreasing evaporation, thus maintaining water accessibility for your plants.
The drying action of UV rays hitting the soil surface is a major reason for plant drought stress. Mulch helps reduce evaporation, ensuring that water stays accessible to your plants for longer. It also helps regulate the soil temperature, which is why straw or leaf litter is so essential for keeping crops cool in scorching weather.
Simultaneously, mulch prevents weeds from competing with your crops for water. A nice 1-3” thick layer is great for potted or in-ground plants. Be sure to choose a mulch that is finely shredded, dry, and free of weed seeds or any signs of disease. If you use drip lines or soaker hoses to irrigate, place the mulch over the top of the irrigation system to ensure water penetrates the soil. Think of mulch as the final “icing on the cake.”
4. Practice Consistent Irrigation
Using a garden calendar to monitor your watering schedule and assessing soil moisture before irrigating is recommended.
Consistency is the name of the game when irrigating. It may take some time to get to know different plant species’ needs, but once you do, establish a watering schedule to keep you on track. Once you fall into a routine, you’ll know which garden areas you need to check daily versus weekly. Changing seasons will also affect your schedule.
In general, it’s better to water less frequently but deeply rather than frequent, shallow watering. Use a garden calendar to help track your irrigation, and always check the soil moisture before irrigating.
5. Use Proper Containers
To prevent drought in potted plants, choosing suitable containers with drainage holes is essential.
The key to drought prevention in potted plants is using proper containers. Your pots need a drainage hole to ensure you water thoroughly. When water pours out of the drainage hole, you know it has seeped through all the soil layers in the pot, and you can stop irrigating.
This is an important way to prevent overwatering as well. Earthen containers like clay, terracotta, or ceramic are ideal for maintaining consistent moisture while ensuring breathability.
6. Monitor Soil Moisture
Regularly checking the soil moisture in your garden pots is an important routine.
A soil moisture meter or your finger are essential ways to gauge soil moisture levels. If the top 2-3 inches of soil feel dry to the touch, it’s time to water. It becomes a quick routine to stick your finger in all of your garden pots and beds every other day. This can be a fun way to help get kids involved in the growing process.
Never let the soil get bone dry. When little to no soil sticks to your finger, it’s usually time to water. If lots of soil sticks to your skin like brownie batter, you may be overwatering and need to let the plant dry out a bit.
7. Group Plants With Similar Needs
Simplify your irrigation routine by categorizing plants based on their shared water and soil requirements.
Make your irrigation routine easier by grouping plant species with similar water and soil needs. For example, a drought-tolerant Mediterranean garden bed may include oregano, rosemary, lavender, sage, and thyme. All of these plants enjoy extra well-drained, gravelly soil and infrequent watering.
Similarly, if you want to grow a lush annual garden bed, group extra thirsty plants like cucumbers, tomatoes, and cabbage in adjacent areas so you can amend the soil with lots of compost and water them on the same schedule.
Learn more about companion planting to master the art and science of pairing plants together based on complementary needs.
8. Grow Drought-Tolerant Plants
Consider planting drought-resistant native species if you lack time for regular garden watering.
If you live in a harsh, dry climate or you don’t have time to water your garden very often, consider moving away from thirsty, needy plants. Instead, grow species that are adapted to dry soils. Drought-tolerant native plants are an excellent option for xeriscaping and rock gardens. Indoor growers may opt for cacti and succulent houseplants that thrive on very little moisture.
9. Properly Prepare for Vacations
Before going on vacation, take steps to prevent your plants from suffering water stress.
Underwatering most commonly happens when people go on vacation. Unanticipated heat waves or harsh summer sunlight can dry out your garden more quickly than anticipated, causing severe wilting and other symptoms when you return.
To prevent major water stress while on vacation, properly prepare your plants before you depart by deeply watering, mulching, and installing slow-release irrigation tools like an olla or timed drip irrigation. You may want to hire a neighbor or plant sitter to check on your plants every few days to ensure all your hard work doesn’t go to waste while you’re soaking up the summer sun away from home.
In summary, underwatering most often resembles wilted, yellow, brittle, shriveled leaves with cracked, dry soil. You need to check for at least 2-3 drought symptoms before adding a lot of water to the soil because underwatering sometimes looks similar to overwatering, disease, and soil issues.
Most plants can bounce back from drought if you rehydrate their soils and remove damaged foliage. Deep, thorough watering and regularly checking soil moisture are the keys to recovery and prevention.