I like to grow marigolds because they are a beautiful flowering plant. It also protects my container garden from harmful pests and attracts beneficial ones. But there are problems that can cause the marigolds themselves to die.

Pests that will kill your marigolds are aphids, snails, slugs, thrips, whiteflies, spittlebugs, leafhoppers, spider mites that suck the sap out of the plant. Diseases such as verticillum wilt, blight, and root rot may also kill marigolds. Overwatering or underwatering is another reason.

I’ve written some more details about each of these problems that you may face with your marigolds. Go through them to get an idea of what’s causing an issue with your plants and take steps to fix it.



This harmless-looking bug, the larvae of a froghopper, feeds on the plant by piercing the stem and sucking out the plant juices. These bugs are hard to detect as they are great at hiding!

They camouflage themselves by producing a huge amount of froth and hiding out in the middle of it. Once the larvae have hatched, each nymph feeds for up to 3 months, with the adult moving and feeding off the plant for up to 6 months. They can cause damage to the plant by stunting plant growth but are considered to be problem pests.


Ants farming aphids on my pepper plants
Ants farming aphids on my pepper plants

Tiny insects, commonly known as plant lice and greenflies; these pests can cause a huge amount of damage to marigold plants. An infestation by aphids is evident in the way the plant appears – stunted growth, curled foliage, mottled leaves, and a sticky secretion on the new buds and leaves.

In warmer climates, aphids don’t lay eggs but rather lay live nymphs, which take ten days to reach adulthood. The nymphs bite into the underside of a leaf and feed on the plant’s sap and inject the plant with a toxin that causes it to wither.


Small insects with a big appetite, leafhoppers, can damage plants by feeding on the sap and excreting a toxin that can discolor the flowers and disfigure the leaves.

The insect lays its eggs on the underside of the leaves, and they will stay there until they hatch in a few weeks. They can lie dormant for a few months and only hatch when conditions are right for them.


A slug is a snail that does not have a shell. While it does not sound extremely dangerous, a slug can harm a marigold plant by eating the root of the plant and killing it. A marigold plant is often used as a sacrificial plant by gardeners. 

Snails love eating the marigolds, so the plant is planted in clusters around plants which the gardener would like to protect, and the marigold draws the snails away from the protected plants.


The marigold family is most often attacked by a fungal disease called verticillium. This results in wilting leaves. The fungus is soil-borne, but the spores can be transported via wind and water. 

The plant can also be attacked by blight, root rot, and mildew, which causes the buds to shrivel and forms brown spots on the tips of the leaves, and in extreme cases, can cause the plant to die.


Sometimes water can be a hindrance to your marigolds growth and can cause it to flounder rather than flourish. Overwatering can cause excess moisture in the soil, which causes root rot. Make sure that your soil has proper drainage before planting the marigold, which should curb the problem. 

The signs of root rot would be evident in the plant as it will become wilted, then slowly begin to yellow, then eventually collapse. Root rot is a disease that cannot be cured, so check your plants regularly for signs of it, provide good soil, and don’t overwater

Your marigold plant does need to be watered regularly, especially during the hot summer days. Never allow the plant to dry out as, even though it is a hardy plant, it cannot survive drought conditions.

What To Do When Bugs And Slugs Attack My Marigolds

There are ways that you can prevent the attack on your marigolds by bugs and slugs

Spittlebugs – eggs, and nymphs are attacked by natural predators like assassin bugs, spiders, and various parasitic wasps, so if you do have spittlebugs living on your plants, allow the natural predators to do their job! You can wash off the froth by using soap and water, or if the infestation is large, prune off the affected stems, which will get rid of the bugs before they can breed again and cause further damage to the plant.

Aphids prune the infected leaves from the plants and destroy them. Spray the plants with water and knock the aphids off the plant. Introduce ladybugs to your garden as they also feed on aphids and will quite happily get rid of your problem!

Leafhoppers – these insects move quite quickly, so it’s best to get rid of them while they are in the egg or larvae cycle by using insecticidal soaps to wash the eggs or larvae off the leaves preventing them from hatching or reaching adulthood. A good defense mechanism to prevent the adult leafhoppers from attacking marigold flowers is to cover the plant with garden fleece, stopping the leafhopper from getting access to the plant.

Slugs – to protect your marigold plants, simply dig around the roots of the plant until your find a slug and remove it. There are many at-home remedies available to prevent slugs from eating your plants, such as using small shallow dishes of cornmeal to lure and trap the slugs.

How Can I Practice Disease Control On My Marigolds? 

The prevention of diseases in marigolds is time-consuming but can and should be done to produce beautiful plants. The aim is to prevent or control the disease to minimize the loss

There are many commercial fungicides and pesticides available to aid with the prevention of diseases in the plant, but there are just as many natural solutions available that are less harmful to the environment. 

The natural ways include spraying the plants with a mixture of neem oil and water, rubbing mildew off the plants once it becomes visible, or simply pruning the damaged leaves and stems and destroying them. If you have a stubborn infection that you cannot get rid of, contact your local Garden Centre for further advice.

How To Care For My Marigolds

To keep your plants in tip-top condition and to assist in keeping your garden healthy, try these tips:

  • Spread organic material over the soil between plants to discourage weeds and keep the soil moist.
  • Water marigolds regularly, but don’t overwater.
  • Snip off dead blossoms to stimulate new growth.
  • Stake the plant with a small stake if it gets too heavy.
  • Split the plants regularly and transplant so that they are not overcrowded.
  • Check for bugs, slugs, and diseases and take steps to control the problem.


Marigolds are a hardy plant and will generally grow anywhere if the conditions are right for the plant. Although they are not bothered by many pests, there are a few who are attracted by the wonderful marigold plant and who will try to cause harm to it.

A small amount of care every day will allow your marigold plant to live a long, colorful, productive life if you keep it free from pests and diseases.

The marigold plant is a great addition to your garden and can be planted as a border to repel and deter an array of bugs that will try and attack the other plants in your garden. 



  1. Leaves are chewed off my marigold seedlings, not snails or slugs. The seedlings are in an old plastic clam shell container fruit was in, the remaining stems appear to be healthy. I sprinkled the remaining seedlings and soil with cayenne pepper. This is not the first time for the decimation but the first time I’ve tried cayenne pepper

    1. Hey Susie, I would suggest finding out what exactly is eating the leaves. That makes it easier to take care of the problem. Maybe you’ll find this post helpful.

      If there are large cuts on the leaves, it could be one of beetles, caterpillars, snails, slugs, or sawflies. It could even be animals chewing the leaves. If you’re struggling to find exactly what they are you can start with organic methods like neem oil spray or diatomaceous earth. I would still recommend first finding out what exactly is the pest eating the leaves.

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