What To Do When Your Dianthus Looks Dead?

If you’ve been tending to your dianthus plant with care, it can be disheartening to see it looking lifeless and wilted. There are a few steps you can take to try and revive your dianthus and bring it back to life. 

So, what to do when your dianthus looks dead?

The first step would be figuring out what is wrong with your dianthus. Diseases like rust, fusarium, and insects like aphids, red spiders, and snails etc. can cause your dianthus to look lifeless. Depending on the cause, you need to apply chemical treatment, qurantine affected plant. Also, your dianthus needs special care to thrive, so make sure you are treating it properly.

In this article, we’ll go over some common causes of dianthus looking dead and what you can do to prevent it from happening again. 

Why Do Your Dianthus Looks Dead?

There could be several things that can make your dianthus look dead. Like the natural process of calla lily flower turning green making it seem like dying.

Problem Symptoms Cure Prevention
Rust Pupils with powdery spores with a yellow margin, Curled up or dead leaves Removing affected dianthus leaves, using Azoxystrobin  Using horsetail tea, chamomile syrup
Fusarium Yellowing, wilting, and drying of the lower leaves, shriveled and grayish stem, brown xylem tissues, stunted and abnormal growing of the shoots, roots and stems rotting. N/A Using soilless potting mix or sterilizing the soil, keeping affected plants in quarantine, keeping the pH of the media near neutral
Alternariosis Purple spots on the leaves,

loss of leaves,

decreased plant vigor, 

broken stems

Getting rid of old leaves, spacing plants, avoiding overhead irrigation,

using Avelyo.

Using fertilizers containing potassium and phosphorus, avoiding excessive soil moisture

and keeping a temperature below 50 degrees F.

Gray Rot Necrotic lesions, 

soft and watery gray rot, 

gray mycelium

Reducing humidity level to below 85%, 

ensuring good air circulation,  keeping affected plants in quarantine, providing light to lower leaves, 

avoiding prolonged wetness,

using ethylene blockers.

Keeping the environment dry.

keeping cracks from birds, bugs, and other pests at bay.

ventilate well.

Aphids honeydew coats, pale green leaves, misshapen, curled, stunted, or yellowing of the leaves, distorted or deformed flowers, or fruit Using a strong stream of water, neem oil, insecticidal soaps, or horticultural oils, A mild solution of water and dish soap, Diatomaceous  Using companion plants to repel or distract aphids
Snails N/A Spraying with garlic and onion extracts or use molluscicide products N/A
Red Spider Leaves with yellow dots that weaken and die.

spider webs on the undersides of the leaves.

Cleaning your plants with lukewarm water, use permethrin or pyrethrin, 

using insecticidal soap or horticultural oil, and a 70% isopropyl alcohol solution. 

Overwatering Looks dead Keeping it in a gritty mix and out of the full sun  Watering not more than once a week

First, we will go over all the common dianthus diseases. After that, we will discuss whether there was any error on your side.

Dianthus flowers
Source: Houzz

Reason One: Rust

A fungus causes rust on Dianthus flowers, producing pustules and a powdery appearance on the leaves and stems.

Plants are usually affected by it when they’re subjected to constant humidity. It takes nutrients from the plant and spreads throughout the leaf. It can cause malformations in the petals of dianthus plants, leading to their death if left untreated.


  1. Breaking out of pupils with powdery spores, up to 0.25 inch, on leaves, buds, and stems. 
  2. Yellow margin surrounding the pustules.
  3. Leaves curling up and often dying.
  4. Girdling of the stem when several pustules form around a shoot. 
  5. Stunting of the plants causing no flowering.


First, remove all the affected leaves so that it cannot spread. You must also leave affected leaves that are on the ground as well.

To fight the disease, strong active fungicides such as Azoxystrobin can be used as foliar spray. Ensure there is a 14-21 days interval for spraying Azoxystrobin for adequate protection from rust. 


The rust can be prevented using natural remedies. Horsetail tea has powerful medicinal properties that help prevent this infection.

Add 400 g of chopped mackerel to 1 liter of boiling water, turn off the heat, and wait for 15 minutes. Afterward, strain, let cool, and spray the dianthus plant every week for a month. 

Make chamomile syrup if you cannot find horsetail tea. To make chamomile syrup, you will need 1 cup of water, 1/2 cup of sugar, 1/4 cup of dried chamomile flowers, and 1 juiced lemon. 

Boil water in a pan. Add the sugar and chamomile flowers to the boiling water. Stir until the sugar is fully dissolved. Reduce the heat and simmer for 5 minutes. 

Pour the syrup into a bowl and press down on the flowers to extract all the liquid. Add the lemon juice and stir to combine. Put the syrup in a spray bottle for usage.

Reason Two: Fusarium

Fusarium is naturally found in the soil. The main cause of this infection is the nutrient imbalance in the soil. 

Other causes are high temperatures and moist, acidic soil. However, there is no cure for this disease. The best you can do is prevent it from spreading. It will trun dianthus yellow similar to how a snake plant leaf turns yellow.


  1. Yellowing, wilting, and drying lower leaves on one side of the plant. 
  2. Curling of the plants if symptoms appear on only one side. 
  3. Shriveled and grayish stem. 
  4. Browning xylem tissues. 
  5. Stunting and abnormal growing of the shoots. 
  6. Rotting roots and stems in the late stages of the disease.


Use soilless potting mix or sterilize your soil. To sterilize the soil, cover it in multiple layers of transparent plastic and leave it in direct sunlight. The heat generated from the sun would be enough to sterilize it. Do this for a couple of hours every day for four to six weeks.

If you do not have sunlight, preheat your oven to 180°F and place the soil in a baking dish. Cover the dish with foil and bake for 30 minutes. Let the soil cool before using.

Keep the diseased plants away from your garden. Do it as soon as you see the symptoms.

Keep the pH of the media near neutral and avoid over-fertilizing. The neutral pH level is 7, so if your medium’s pH is too low, add lime or sulfur. If it’s too high, use acidic fertilizers. 

Reason Three: Alternariosis

Alternaria alternata, a fungus, affects both the leaves and flower stems of Dianthus, filling them with spots.

At first, it’s punctual, but most of the time the spots spread until they cover the whole leaf, causing the leaves to curl up and dry.


  1. Purple spots all over the leaves,
  2. Loss of leaf area,
  3. Decreased plant vigor, 
  4. Broken stems, and 
  5. Dead plant.


To control Alternariosis on dianthus, practice good cultural management. One of the key steps is to remove and destroy infected plant debris to reduce the number of fungal spores in the soil. This can prevent the spread of the fungus to healthy plants.

Keep the area around the plants clean and free of debris as well. Provide the plants with adequate light and nutrients in order to promote a healthy growth process.

Air circulation can also be maintained by spacing plants appropriately, which can prevent the spread of the fungus. The spacing should be between 12-18 inches.

Fungicides such as propiconazole or myclobutanil can be used as a curative measure to stop the progression of the disease.


  1. Use fertilizers that contain potassium and phosphorus. 
  2. Avoid excessive soil moisture.
  3. Keep the plants at a temperature below 50 degrees F.

Reason Four: Gray Rot

The dianthus suffers from gray rot disease frequently. This can cause spots and rot, which eventually lead to the death of the plant’s flowers and fruits if the infection persists.


  1. Necrotic lesions, 
  2. Soft and watery gray rot or 
  3. Gray mycelium 


To control gray rot on dianthus plants, remove or isolate infected or old plants, as they can be a source of fungal spores that can infect healthy plants.

Reduce humidity levels to below 85% and ensure good air circulation. Spacing plants at least 12–18 inches apart can help to ensure that air can circulate freely and dry the foliage quickly.

Allowing light to reach the lower leaves and making sure that plants do not remain wet for long periods can also help to inhibit the growth of the fungus.

Another strategy is to use ethylene blockers like EthylBloc, which can slow down the ethylene production of the plant and prevent flower from aging and wilting.

To use EthylBloc, dip a sachet in clean water and placed immediately in the container with the plant, making sure the sachet does not touch the flower heads. The container should then be immediately closed for at least 4 hours.


  1. Make sure the environment is not highly humid.
  2. Prevent small cracks caused by birds, insects, and other pests.
  3. Ensure good ventilation.
Gray Rot
Source: Better Home and Gardens

Reason Five: Aphids

Aphids can infest dianthus plants when the air is dry, causing wilting and yellowing of the leaves. They also excrete honeydew, which can attract other insects and promote the growth of sooty mold fungus. This is especially common during the cold season.


  1. Misshapen, curling, stunted, or yellowing leaves
  2. Aphids hidden on the underside of leaves 
  3. A sticky substance on leaves or stems frome aphids feeding on the plant
  4. Pale green leaves due to honeydew excretion; stimulate the growth of sooty mold
  5. Distorted or deformed flowers or fruit, causing loss of crop yield
  6. Galls formed on roots or leaves


Spray infested plants with a strong stream of water. The water pressure can damage the delicate bodies of the aphids, knocking them off the plants.

Alternatively, you can spray dormant horticultural oil on your plants to kill overwintering aphid eggs, or you can use neem oil and insecticidal soap.

A mild solution of water and dish soap can often be used to wipe or spray the leaves of plants. This solution can suffocate the aphids and make it difficult for them to feed. For two weeks, soapy water should be reapplied every 2-3 days to ensure the control of the infestation.

Additionally, using cayenne pepper can be a useful method. By mixing 1-quart water, 1 tsp liquid dish soap, and a pinch of cayenne pepper, spray directly on plants without diluting can provide an effective solution.

Another way of controlling aphids is to use diatomaceous earth. DE is a non-toxic material that dehydrates aphids, killing them by making it difficult for them to retain moisture. 


A companion plant can help repel aphids or distract them from plants that you want to grow. Catnip, garlic, and chive plants can repel aphids.

Their favorite plants, however, are mustard and nasturtium. The best way to use these as aphid traps is to plant them near valuable plants. Aphids will likely attack these plants before your prized dianthus. 

Reason Six: Snails

An extended period of rain may trigger the appearance of snails when humidity levels are very high in the environment.

Snails are very damaging to dianthus flowers since they can feed on every part of them.


If caught early, slugs can be treated with garlic and onion extracts, making them fairly easy to remove. Put a clove of garlic and an onion into a liter of water and blend. Leave the mixture for about 10 minutes. Then fill a spray bottle with the liquid after removing the solids.

Spraying your dianthus with the liquid every few days should fight off the snails.

Alternatively, there are molluscicide products on the market that can achieve this goal as well.

Reason Seven: Red Spiders

Unlike slugs, red spiders begin to exhibit their effects when the relative humidity decreases. The attack of these insects manifests directly on the dianthus leaves, as they feed on the sap.


  • Small yellow dots appear on the leaves.
  • Spider webs can be found on the underside of the dianthus leaves.


To control spider mites on dianthus plants, regularly clean the foliage using a soft cloth or lukewarm water to remove the mites and their eggs. Use insecticides with permethrin or pyrethrin, following the instructions on the label for application rate. Insecticidal soap or horticultural oil can also be effective. Additionally, using a 70% isopropyl alcohol solution can be a non-toxic method, but it should be used with caution as it can dry out the leaves.

Reason Eight: Overwatering

One of the mistakes some people make with dianthus is that they water it every day. Dianthuses prefer dry ground; watering them every day would put them under a lot of stress.


The only thing you can do is keep it in a gritty mix and hope for the best. In the meantime, keep it out of the full sun to reduce the stress and see if it survives. Also, get rid of all the dead flowers so they can grow. 

If there is a sufficient amount of green stem present, a cutting can be taken from the dianthus plant to regrow it. Re-pot it in a small grit pot, water it once, and keep it somewhere sheltered until new growth appears.


Water your dianthuses no more than once per week. Check the soil moisture level before watering, as overwatering can lead to root rot.

How to Take Care of Your Dianthus Plant?

To prevent your lovely dianthus plant from dying, you need to take better care of it. Here are three tips you can follow-

Water Properly:

Dianthuses thrive in dry ground; that’s why they grow well in gravel or alpine gardens. To water dianthus properly could be tricky, as they need a very small amount of water. So, do not water them more than once a week. Make sure the drainage is adequate as well.

Remove Dead Flowers:

It is necessary to deadhead dianthus flowers after they bloom because the petals will wither and fade at this point. With sharp scissors or pruning shears, prune any petals or leaves that don’t look good to encourage healthy growth.

Adequate Sun Exposure:

Keeping the dianthus in a comfortable environment is crucial. An ideal environment for dianthus would be full sun with partial shade, dry weather, and well-draining soil. Otherwise, they become vulnerable to viruses, bacteria, fungi, and insects.

Get to know the dianthus plant’s requirements before you buy it so you can select the right soil.

Despite being able to tolerate full sun for up to six hours a day, they will grow best in partial shade. They will return year after year for many years, so you can enjoy them for a long time.

Along with all these, make sure the plant is in great shape before you plant it. Or, if you grow them from seeds, check for seed heads. Seed heads like those in Bermuda seeds are not a good thing.

Frequently Asked Questions (FAQs):

What does dianthus root rot look like?

The base of plants develops reddish-brown spots caused by basal rots. Affected stubs may die, but they do not display vascular discoloration beyond the rotted area. There may be rotted roots and discolored stem bases later on.

How do I know if my dianthus is overwatered?

If the leaves of your dianthus are turning yellow, it may be because of excess water. Either that, or the soil isn’t draining the water well enough.

Can an overwatered plant fix itself?

Some plants can recover on their own if they are overwatered, but it depends on the plant and the extent of the overwatering. The plant is unlikely to recover if its roots have rotted. A plant may be able to bounce back if the overwatering only caused the leaves to wilt.


If your dianthus looks dead, it may be because of an infestation or overwatering. In any case, you need to act fast to revive your plant.

In cases of overwatering, if the roots have rotted, it’s less likely that the plant will survive. If there is some type of infestation, you need to stop the spread, or it will be tough to restore its health.

However, to prevent such incidents, providing your dianthus with the appropriate environment must be taken into account.

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