My Dianthus Looks Dead (7 Reasons+Solutions)

As one of the most popular garden flowers, dianthus liven up every environment they grow in and are appreciated among gardeners for their rich blue-green foliage, beautiful pinkish flowers, and spicy clove-like fragrance.

However, having them thrive and look so gorgeous is not possible without some effort, as they’re rather finicky plants that grow slowly and can be challenging to care for if you’re not 100% sure what you’re doing.

As you grow dianthus, you’re very likely to face different issues, some of which may lead you to ask “why my dianthus looks dead?”

Dianthus may struggle to grow and develop properly for several reasons, and many of them will make it appear lifeless and dead.

Learning why this happens will help you deal with these problems and revive your plant to make it the pride of your garden once again.

In this article, I will explore some of the most common reasons why dianthus plants may appear dead or dying, and provide you with practical tips and advice on how to revive them.

Whether you are a seasoned gardener or a beginner, this guide will help you to keep your dianthus looking healthy and beautiful all season long.

So, let’s dive in and learn how to give your dianthus the care it needs to thrive!

7 Reasons Why Your Dianthus Looks Dead

Dead looking dianthus hanging from a fence.

If you’re wondering “why my dianthus looks dead,” you will have to look at the signs that will tell you what is happening with your plant and what could be a potential reason for your dianthus dying or at least appealing to do so.

There are several causes that can make the plant look lifeless and most of them have to do with certain diseases or pest infestations.

The good news is that, in most cases, there are actions you can take to revive your beloved plant. Even conditions that are incurable can be prevented with proper care and maintenance routine.

Below are the most common reasons that can make the dianthus look dead and a few tips on how to solve those issues.

1. Rust

Rust on a plant leaf.

One of the most common reasons why dianthus may look like it’s dying is rust.

It’s a fungal disease that manifests itself through pustules and powdery buildup on the leaves and stems.

Leaves will also wilt and eventually fall off.

The pustules are no larger than 0.25 inches in diameter and are commonly surrounded by a yellow margin.

Rust takes nutrients from the plant, so it can very damaging and if left untreated can cause dianthus to die. In most cases, the rust will stunt the plant’s growth and prevent it from flowering.

As they can live for up to six months without a host, the fungi causing this disease are very difficult to get rid of and can cause issues in the entire garden.

Rust mostly develops in humid environments, where the temperature ranges from 41°F to 82°F, so plants growing in these conditions frequently suffer from this disease.

What to Do?

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Rust can be treated and cured but it’s important to react as soon as possible. The plants should be treated at the first appearance of stains on their leaves.

The first thing to do is to remove the infected leaves, so the disease won’t spread any further. This also includes collecting and removing any infected leaves from the ground around the plant.

The most common way to fight the rust is by using strong active fungicides and spaying them over the foliage.

Of course, working on rust prevention could save you all this trouble.

The prevention measures include using non-sensitive cultivars, providing the plants with an environment with proper humidity and heat levels, and planting the dianthus with some space between individual plants to increase air circulation.

Another thing to do is to use horsetail tea or chamomile syrup and spray the plants with it every week for a month.

2. Fusarium

Fusarium wilt.

Another disease that can cause dianthus to die if left untreated is fusarium.

This disease is caused by a fungus that initially attracts the root, but then progresses and eventually affects the entire plant.

The fungi that cause fusarium lives in the soil and conditions that favor its development include a nutrient imbalance, high acidity levels, plant moisture, and high temperatures.

At the beginning of the infection, the plant will look healthy.

This is the main issue in dealing with this disease, as, commonly, once you notice the infection, there’s not much you can do for your plant.

Fusarium will rather quickly cause root rot, and the leaves will become yellowish, wilting, and ultimately, drop off.

Also, the stem will become shriveled and grayish, while the growth of the shoots will be stunted.

While the infection can affect any plant, it commonly first attacks the weak and already stressed dianthus.

What to Do?

Unfortunately, the fusarium is untreatable and the best you can do is discard the affected plants to stop the further spread.

So, you should focus all your efforts on prevention and creating the conditions that will hinder the development of fungi.

The first thing you can do is sterilize the soil.

You can do this by covering the soil in transparent plastic and leaving it in sunlight, so the heat can sterilize it.

Also, track the pH levels of the soil and aim to keep it neutral, around 7. If the pH level is too low, you can add lime to the soil to increase it.

If you need to reduce the pH level, you can do it by using acidic fertilizers.

In addition to the methods described above, you should also look to grow more resistant dianthus variants, use quality irrigation water, and only apply the proper fertilizer.

3. Alternariosis

Plant affected by Alternariosis.

Your dianthus can also look like it’s dying if it suffers from the fungal disease known as Alternariosis.

This infection is caused by the fungus called Alternaria alternata and attacks both the leaves and flower stems of the plant, causing purple spots on their surface.

Initially, these spots will appear only sporadically, but as the disease develops they will cover the entire leaf, causing it to wilt, curl, and eventually die.

The plant itself will look much less vigorous, the stems may break off, and the growth will be stunted.

Once the infection has fully developed, the reduced leaf area will prevent the plant from properly functioning and cause it to die.

The fungi that cause this disease can come in different variants, some appearing during planting season, while others developing after the harvest.

In most cases, these issues will arise in hot and humid environments.

What to Do?

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The key to controlling alternariosis is taking proper care of your dianthus.

The most important thing is to, as soon as you notice infection, remove all the affected parts of the plant to stop the spread to other portions of your dianthus and other plants in the garden.

Remember also to pick up the infected parts of the dianthus that have fallen to the ground around the base of the plant so there will be fewer fungal spores in the soil.

Plants should also receive optimal conditions for healthy growth including adequate lighting and proper nutrients.

Plus, pay attention to the spacing between individual plants and keep them at least 12-15 inches one from another to allow for better air circulation and stop the spread of fungi.

Alternariosis can be treated with strong fungicides, such as propiconazole or myclobutanil, as they can slow down the progression of the disease.

4. Gray Rot

Flower affected by botrytis.

Gray rot or botrytis is a very common disease for a large number of different garden plants, including dianthus.

At first, as the plant gets infected, brown spots will appear on leaves and flowers.

As the disease develops, flowers and leaves will begin to rot and, if the infection is allowed to progress, the entire plant will eventually die.

The fungi causing gray rot primarily develop in a humid environment and commonly attack plants that are already stressed using small cracks caused by insects, birds, or other pests.

Getting rid of these fungi is particularly difficult as it can remain on the plant debris and dead tissue and stay dormant until it will find favorable conditions to develop.

What to Do?

Like in the case of other fungal infections, the first step in dealing with gray rot is to isolate or remove the infected dianthus, so the disease doesn’t spread to healthy plants.

Also, make sure to maintain an environment with low humidity and good air circulation. Space the plants at around 15 inches one from another and keep the humidity below 85%.

The light should be allowed to reach all parts of the plant, including the lower leaves, so make sure to do some pruning if necessary and remove any obstructions that could be blocking the sunlight.

However, be extra careful when pruning and handling your dianthus, as any damage to the plant will make it more vulnerable to gray rot.

Another way to fight these infections is by using ethylene blockers that slow down’s plant’s ethylene production and therefore make the plant more vigorous and prevent flowers from wilting.

5. Aphids

Aphids on a plant stalk.

Besides fungal infections, a common reason why you may find yourself asking why my dianthus looks dead is the pest infestation.

Aphids are probably the best know of these pests and they are known to often attack dianthus, especially when the air is dry.

Aphids suck out the sap of plants’ leaves, making them lose their green color and turn yellow, wilt, dry out, and make the whole plant look like it’s dying.

In addition, aphids excrete honeydew which attracts other insects and provides a favorable environment for fungi development.

What to Do?

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You physically remove aphids from dianthus by spraying the pants with a stream of water. Aphids are fairly delicate insects and the water should knock them off the plants they infested.

Alternatively, you can use simple and fast-acting insecticides or go the more natural way and spray the plant’s leaves with a solution of water and dish soap.

Neem oil is also rather effective against aphids and should kill overwintering aphid eggs.

Finally, you can introduce some predatory insect species, such as ladybugs, and let them take care of the infestation.

6. Snails

A snail on a flower.

Snails are another type of pest that finds the leaves of dianthus particularly delicious.

They usually appear in the gardens after extended rain periods, when the level of humidity is particularly high.

While they love the leaves, they will also feed on other parts of the plants, seriously damaging them, stunting their growth, and, in some cases, causing them to die.

What to Do?

There are several completely natural ways to deal with snails. If their number is still relatively small, you can simply pick them up by hand and throw them in a bucket filled with soapy water.

Furthermore, you can spray your dianthus with a mix of water and garlic or onions, The strong smell will deter the snails and keep them away from your plants.

Another way to deal with snail infestation is to prepare traps made by filling a saucer with beer. It will attract the snails, who will crawl in and die.

7. Red Spiders

Red spider on a plant.

Red spider infestation is another potential cause of why your dianthus may look like it’s dying.

Unlike snails, they enjoy an environment with low levels of humidity and directly attack the leaves, feeding on the sap.

Initially, the leaves will have small yellow spots on them, but, over time, they will begin to wild and dry out.

Eventually, they may fall off and cause the entire plant to die. Another sign of red spider infestation is spider webbing you can find on the underside of leaves.

What to Do?

The best way to control the population of red spiders in your garden and protect your dianthus is to frequently clean the leaves with a soft cloth and lukewarm water.

This will not damage the plants but will remove spider mites and their eggs. In addition, you can use insecticides or horticultural oil to eliminate red spiders.


As you can see, your dianthus may appear dead for several reasons. The plant may seem lifeless due to various fungal infections or pest infestations.

However, in most cases, even if your dianthus looks dead, there’s no reason for panic.

Most of these issues are treatable and can be solved rather quickly, making your plant look lively and fresh again.

However, it’s best that you try not to put your dianthus at risk of these problems and work on preventing these issues. I

t’s best done by applying the best cultivation practices and making sure that your dianthus grows in an environment that’s optimal for the plant, but won’t favor the development of fungal infection or attract various pests.

Melissa Johnson
Melissa Johnson

Hello, I'm Melissa, owner and author of this website. I hope my article was able to help answer your questions. If you want to learn more about me, click the home icon above.

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