Common Swiss Chard Problems and How to Fix Them
Swiss chard is one of the most reliable leafy greens you can grow. It produces for months, handles a range of conditions and gives you a steady supply of leaves from a small space.
But even chard has its problems. Leaves get chewed, edges turn brown, plants wilt in the heat. If you do not know what you are looking at, it can be difficult to tell whether the problem is pests, disease, watering or nutrients.
This article covers four of the most common Swiss chard problems we have faced in our own garden at Raikana Primary School in Pretoria: pest damage, tip burn, wilting and root rot. For each one, I explain what the problem looks like, what causes it and what we have done to fix it.
If you want to see how our chard was transplanted and harvested first, I covered those stages in how to transplant Swiss chard seedlings for best results and how to harvest Swiss chard for continuous growth.
In This Article
- Problem 1: Holes in the leaves (pest damage)
- What causes holes in Swiss chard leaves
- How we dealt with pest damage
- Problem 2: Brown edges and tip burn
- What causes tip burn in Swiss chard
- How we treated tip burn with Epsom salt
- Problem 3: Wilting and leaf distortion
- What causes wilting in Swiss chard
- How we used shade nets to reduce heat stress
- Problem 4: Root rot and damping off
- What causes root rot in Swiss chard
- How to prevent and treat root rot
- What I learned from these problems
Problem 1: Holes in the Leaves
One of the first problems you notice on Swiss chard is holes in the leaves. Sometimes the holes are small and scattered across the leaf. Other times, large sections of the leaf blade are missing entirely, leaving only the stem and veins.
In our garden, we saw both patterns. Some leaves had small irregular holes chewed through the blades. Others were eaten down to almost nothing.
This kind of damage does not usually happen overnight. It builds up over a few days as pests keep feeding on the leaves.
What Causes Holes in Swiss Chard Leaves
The most common culprits behind holes in Swiss chard are:
- Caterpillars: feed on leaf blades, often leaving irregular holes. They usually work from the underside of the leaf.
- Beetles: some beetles chew through leaves and stems.
- Birds: peck at tender leaves, especially young growth.
- Slugs and snails: leave larger, jagged holes and often feed at night.
Each pest leaves a slightly different pattern. Caterpillars usually leave small to medium holes. Slugs and snails leave larger, more ragged holes. Birds leave torn edges and missing sections rather than round holes.
The best way to identify the pest is to look at the plant closely at different times of the day. Caterpillars and beetles are easier to spot in the morning and evening. Slugs and snails are usually active at night.
How We Dealt With Pest Damage
In our garden, we combined several approaches rather than relying on a single solution.
First, we removed damaged leaves from the plants. This reduced the number of hiding places for pests and stopped the damaged leaves from attracting more.
Second, we inspected the undersides of the remaining leaves regularly. Caterpillars often hide there, so checking each plant carefully gives you a chance to remove them by hand before they cause more damage.
Third, we used physical barriers where possible. Cardboard collars around the base of young plants helped reduce cutworm damage. Floating row covers can protect plants from birds, beetles and caterpillars if they are placed over the bed before the pests arrive.
Finally, we accepted some level of damage. Swiss chard is a fast-growing plant. Some holes here and there do not stop the plant from producing. The key is to keep the damage below the level that affects the harvest.
Gardening Lesson
Holes in Swiss chard leaves are a sign of active feeding. Check the undersides of leaves and inspect the garden at different times of day to identify what is eating your plants. Removing damaged leaves, handpicking pests and using physical barriers are often more effective than spraying.
Problem 2: Brown Edges and Tip Burn
Another common Swiss chard problem is browning along the edges and tips of the leaves. The edges dry out, turn brown and become crisp. In more severe cases, the entire leaf tip curls and dies.
This is called tip burn. It is not a disease, but a stress response from the plant.
In our garden, we noticed tip burn mostly on the older outer leaves during hot, dry weather. The inner leaves stayed green, but the outer ones showed clear browning along the edges.
What Causes Tip Burn in Swiss Chard
Tip burn in Swiss chard usually has one of these causes:
- Inconsistent watering: when the soil dries out and then gets soaked, the plant struggles to move nutrients properly.
- Nutrient deficiency: especially calcium and magnesium. Both are needed for healthy leaf edges.
- Sun and heat stress: intense midday sun can scorch the leaf tips, especially on larger leaves.
- Salt buildup: in container gardens or heavily fertilised beds, salts can accumulate and damage leaf edges.
In our case, the tip burn appeared during a hot, dry stretch with irregular watering. The combination of heat stress and inconsistent moisture was likely the main cause.
How We Treated Tip Burn With Epsom Salt
Once we identified tip burn, we focused on two things: improving the soil moisture and giving the plants the magnesium they needed to strengthen their leaf tissue.
We used Epsom salt as a magnesium source. Magnesium helps plants move nutrients into the leaves and supports the structure of the leaf edges. Epsom salt is not a complete fertiliser, but it is a simple and affordable way to correct a magnesium deficiency.
Here is how we applied it:
- We mixed one tablespoon of Epsom salt into one litre of water.
- We watered the soil around the base of each plant with the mixture.
- We repeated this every two weeks until the tip burn stopped spreading.
We also made a point of watering more consistently. Swiss chard does best when the soil stays evenly moist. Long dry spells followed by heavy watering are one of the main triggers for tip burn.
Adding mulch to the beds helped too. The mulch layer kept the soil cooler and slowed evaporation, which made it easier to keep moisture levels stable.
Within a few weeks, the new growth came in with clean, green edges. The older damaged leaves were harvested and removed, and the plant continued producing healthy leaves.
Gardening Lesson
Tip burn is a stress signal, not a disease. It usually points to inconsistent watering, nutrient deficiencies or heat stress. Consistent watering, mulch and a magnesium boost through Epsom salt are a practical first response.
Problem 3: Wilting and Leaf Distortion
The third problem we faced was wilting. The leaves drooped, lost their crispness and sometimes showed distorted growth. The plant looked tired and stressed even when the soil was not completely dry.
This kind of wilting is different from the normal droop you sometimes see at the end of a hot day. When a Swiss chard plant wilts from heat stress, it can recover overnight. When it wilts because of a deeper problem, it stays down.
What Causes Wilting in Swiss Chard
Wilting in Swiss chard is usually a sign of one of the following:
- Heat stress: when temperatures climb and the plant loses water faster than it can take it up.
- Uneven watering: long dry periods followed by heavy watering stress the root system.
- Poor soil structure: compacted or poorly drained soil makes it hard for roots to absorb water properly.
- Root damage: pests, disease or physical damage to the roots can cause wilting even when the soil is moist.
In our garden, the wilting was linked to heat stress and inconsistent watering during a hot spell. The soil was drying out faster than we could keep up with, especially in the beds that received full afternoon sun.
How We Used Shade Nets to Reduce Heat Stress
Once we identified heat stress as a major factor, we installed shade nets over the beds. The shade nets reduced the intensity of the midday sun without cutting out all the light the plants needed.
Shade nets are useful because they:
- Reduce the temperature of the leaves
- Slow down moisture loss from the plant
- Protect leaves from direct sunburn during the hottest hours
- Keep the soil cooler, which helps the roots function better
We placed the nets over the beds at a height that allowed air to keep moving through the plants. Airflow matters. A shade net that traps hot air underneath can make the problem worse.
The results were noticeable within a few days. The plants stopped wilting during the hottest part of the day and the new leaves came in stronger and greener. The older leaves that had already been damaged were harvested and removed.
How Rain Affected the Plants
During this period, we also had two full days of steady rain. This was helpful because it gave the soil a deep, slow soak that irrigation struggles to match.
After the rain, the plants recovered quickly. The soil moisture was even, the leaves perked up, and the plants looked noticeably healthier for the next week.
This experience made an important point clear. Swiss chard does not like irregular watering. It likes steady, consistent moisture. When the plant has enough water, it can handle heat much better and resists most stress problems.
Other Fixes We Use for Wilting
Along with shade nets, we use several other practices to reduce wilting:
- Mulching: keeps the soil cool and reduces evaporation.
- Deep watering: watering slowly and deeply encourages roots to grow deeper, which makes the plant more resilient.
- Consistent watering schedule: chard does better with a steady routine than with occasional heavy watering.
- Checking soil moisture: pushing a finger 5cm into the soil tells you if watering is needed.
Gardening Lesson
Wilting is a signal, not a disease. It usually means the plant is losing water faster than it can take it up. Shade nets, mulch and consistent watering solve most wilting problems in Swiss chard.
Problem 4: Root Rot and Damping Off
Root rot is one of the most serious problems a Swiss chard plant can face. Unlike pest damage or tip burn, root rot is not always visible until the plant is already struggling.
By the time you see the plant wilting and turning yellow, the damage below the soil can already be severe. In our garden, we found plants that looked fine above the surface but had dark, mushy roots underneath.
What Root Rot Looks Like
Root rot usually starts below the soil, so it is not always easy to notice early. The signs to look out for are:
- The plant wilts even when the soil is moist
- Lower leaves turn yellow or brown
- The base of the stem becomes dark, soft and mushy
- The roots are brown or black instead of pale and firm
- The plant does not recover after watering
In the photograph above, you can see a seedling that was pulled up from the bed. The base of the stem is dark and clearly decaying. The tissue has broken down and the roots are no longer functioning.
Once a plant reaches this stage, it is not going to recover. The best thing to do is remove it from the bed so the problem does not spread to the plants around it.
What Causes Root Rot in Swiss Chard
Root rot is almost always linked to too much moisture around the roots. Swiss chard does not like to sit in wet, waterlogged soil, especially in cool weather when evaporation is slow.
The main causes of root rot are:
- Overwatering: the soil stays wet for too long, and the roots are starved of oxygen.
- Poor drainage: heavy clay soil or blocked containers hold water around the roots.
- Compacted soil: when the soil is packed tight, water cannot drain away properly.
- Cool, wet weather: slow evaporation during cool spells makes waterlogged soil worse.
- Fungal pathogens: once soil is waterlogged, fungi like Pythium and Phytophthora can attack the roots.
In our case, the root rot was tied to overwatering during a cooler spell. The soil was not draining fast enough, and the seedlings that were planted into the wettest section of the bed were the first to go.
How to Prevent Root Rot
The best way to deal with root rot is to prevent it in the first place. Once a plant has it, there is usually no way to save it.
To prevent root rot:
- Water only when the top few centimetres of soil are dry. Push a finger into the soil before watering.
- Make sure your beds or containers drain properly. If water pools on the surface, the drainage needs fixing.
- Add organic matter to heavy soil. Compost and mulch improve soil structure and drainage.
- Do not plant Swiss chard in low spots where water collects.
- Space plants properly so air can move between them.
- Reduce watering in cool or wet weather, when the soil stays moist longer.
- Remove any plant with root rot immediately so it does not spread.
What to Do If You Find Root Rot
If you pull up a plant and find root rot, act quickly. Remove the plant and dispose of it in the bin, not in the compost. Do not leave the roots in the garden or add them to a compost pile.
Check the plants around it. If their soil is waterlogged, skip watering for several days and let the bed dry out. Loosen the soil gently around the remaining plants to improve airflow to the roots.
If the same bed has shown root rot before, consider adding more compost and organic matter to improve drainage before you plant in it again.
Gardening Lesson
Root rot is easier to prevent than to treat. Swiss chard does not like wet feet. Check the soil before watering, make sure the bed drains properly, and remove any plant with rot before it spreads to the rest of the crop.
What I Learned From These Problems
These four problems taught me that Swiss chard is not as tough as it looks. It handles a lot, but it responds quickly when its basic needs are not met.
The main lessons from this experience:
-
Look at the leaves first.
Holes, brown edges and wilting are all visible signs of what the plant is going through. Learning to read them is the first step to fixing the problem. -
Check the soil before watering.
Wilting does not always mean the soil is dry. Sometimes the plant is stressed by heat, not thirst. Sticking a finger into the soil gives a quick, honest answer. -
Consistent watering matters more than heavy watering.
A steady routine prevents tip burn, wilting and root rot. One big soak does not make up for weeks of dry soil, and it can be just as damaging as drought. -
Epsom salt is a practical tool, not a cure-all.
It helps with magnesium deficiency. It does not fix every cause of tip burn. -
Shade nets work.
They are a simple, affordable way to reduce heat stress in Swiss chard and other leafy greens during hot weather. -
Drainage is non-negotiable.
Root rot is the consequence of poor drainage. Fix the soil structure before it becomes a problem. -
Remove sick plants quickly.
A plant with root rot cannot be saved. Taking it out fast protects the rest of the bed.
Gardening Lesson
Swiss chard problems are easier to fix when you catch them early.
Walk through the garden regularly. Look at the leaves, check the soil and watch how the plants respond to the weather. The earlier you notice a problem, the simpler the fix usually is.
Soshanguve, Pretoria, South Africa
Growing Knowledge. Growing Food.