Do your Marigolds look pale-dry, spotted, and jagged even under proper care? It could be the result of some invaders eating your Marigolds.
Here is a guide to help you identify these pests and ways to treat them effectively.
Table of Contents Show
What is Killing My Marigold?
The vibrant color of Marigold flowers is the key attraction for pests and insects.
Along with the unaesthetic appearance, pests nibbling the pinnated leaves of the Marigold can lead to stunted growth.
Here is a list of some notorious species that may eat your Marigold.
1. Caterpillars & Cutworms
Caterpillars chew on the leaves making large holes that destroy young tender Marigolds.
They often reside in the plants and eat them for nutrition until they become butterflies.
Despite the necessity to identify the pests for their correct treatment, you might confuse sawfly larvae with a caterpillar.
Caterpillar is the one with five pairs or fewer prolegs. Moreover, black cutworms and variegated cutworms are easily distinguished by their appearance.
Larvae of these nasty pests binge on the tender roots of the plant.
Till the soil to expose the eggs and larvae to the scorching sun that kills them.
Further, the use of microbial insecticides like Bacillus thuringiensis does best in only controlling the caterpillars.
2. Japanese Beetles
Gardeners use marigolds as ‘bait plants’ for Japanese beetles.
The general idea of planting Marigolds is to protect other plants, like lavender, raspberry, mint, etc., more like companion plants.
Japanese beetles usually have elongated, pointy bodies, which may be brown, brownish-white, and C-shaped.
Apart from the rustic green tint, their foul-rotting smell makes the beetles easily detectable.
You can either handpick the beetles during their active period (May to July) or act upon the grub with insecticidal soap to prevent them from moving toward the root.
Before you decide on using any harsh chemical, remember that adult beetles are not around for long. They fly around within a month.
That said, the most effective measure would be a pheromone trap. But, do not use the trap often as they may attract more external pests harmful to the plant.
3. Common Earwigs
The earwigs are reddish-brown bugs about 3/4 inch long that could be eating your Marigolds.
But having only a few earwigs benefits your garden collection. They eat aphids, snails, slugs, and other insect larvae that help control the pest population.
Nevertheless, earwigs are treated as pests when their damage becomes extensive. Ragged leaves with scattered black dropping are the damage symptoms.
In such cases, spray diluted rubbing alcohol on the insects or DIY the spray by mixing water with 70% alcohol. The earwigs would die in contact with the chemicals.
As roses, dahlias, and ivy harbor more pests, grow your Marigold away from them.
Adding to it, remove all the debris and weeds around the plant that could potentially favor pest growth.
You know it’s the grasshopper devouring your Marigold by observing the damage pattern.
Meanwhile, these pests are most active during the early summer to late fall when the Marigolds bloom.
Even when the bloom fades away, they cunningly feed on leaves, foliage, and whatever is available.
Once the infestation is severe, controlling them becomes nearly impossible due to high mobility and reproduction.
The best way to check the grasshopper population from eating the Marigolds is its natural predator, the bird.
Place a birdbath near the plant so the birds can pick the grasshopper.
5. Slugs and Snails
You won’t notice these nocturnal pests on the plant during the day. However, the slime trail around the plant shows their presence.
Their numbers are reduced during the winter and the hot, dry summers.
Meanwhile, grass cover, mulches, soil cracks, and worm tunnels provide them the places to hide and lay eggs.
Before the egg-laying initiates, try minimizing the pest’s population by handpicking them when they pop out for dinner.
But, if you are like me about disliking the slimy feeling, set up a trap instead.
Place a beer can near your plant and wait for these gooey Molluscans to get dragged toward the fermented odor. It is impossible for them to climb out of the can after drowning.
Likewise, many sprinkle salt to kill the snails. Excessive salt obstructs plant growth, so we do not recommend this method.
6. Aphids and Thrips
Contrary to the myth that aphids and thrips dislike Marigolds, they are the most common pests on many houseplants.
These greenish-yellow pests mostly hide under the leaf and on the stem.
Aphids release a sticky substance called honeydew, which is not harmful, but the sweet secretion throughout the leaves inhibits photosynthesis and attracts ants.
This results in yellow, wilted leaves and stunted plant growth, more like a nutritional or disease problem.
For that, you can simply dislodge the pests with high-pressure water. You might find it easier to hang a sticky trap around your plants to control the pests.
If the pest population does not subside, use diatomaceous earth powder to dehydrate the thrips and cut into the aphid’s body.
Repeat both processes until the pests clear out.
Disclaimer: Consult a professional pest control technician before using diatomaceous earth.
7. Spider Mites
Marigolds attract spider mites because of their many thin leaves, which provide an excellent feeding supply for these chlorophyll-hungry bugs.
It might take a lot to detect the spider mites as they measure less than one millimeter (0.04 inch) and appear in various hues.
Mites dig holes in the foliage of the marigold plant and drain them out of nutrients, subsequently turning brown and dying.
Many species lay small, spherical, initially transparent eggs and construct silk webbing to help shield the colony from predators.
Also, using a tablespoon of neem oil with dish soap works wonders against the mites.
8. Furry Animals
Even if your Marigold is pest free, there might still be some more prominent nemesis ready to pounce on the plant.
These sly animals scratch the bloom, pull and bend the whole plant, eventually messing up the entire garden.
Moreover, nocturnal animals like rats and opossums chew parts of plants’ roots, sometimes making them hollow and causing plants to wilt.
You can spray the seeds and foliage with cayenne pepper to prevent these burrowing creatures from chewing the plant. Or, just scatter some garlic around the plant, as the smell makes rabbits and fluffy squirrels run away.
While the hacks above hold the animals from eating the Marigolds away, create a barrier around the plants using chicken wire.
Is Pest Infestation Common in Marigold?
The musky smell of the Marigolds repels many pests and insects. However, a few garden pests could occasionally be eating your Marigolds.
That said, the root of the French Marigold releases limonene, which has insecticidal properties against white flies.
Marigold roots release a toxic chemical (alpha-terthienyl) which prevents the hatching of nematodes eggs. Similarly, the presence of pyrethrum in Marigold repels mosquitoes.
Do Birds Eat Marigold Seeds?
It might surprise you, but birds don’t generally consume marigolds, neither flower nor seed.
You should cover the plant with a net to protect them from the birds.
Or, simply hang a shiny object like CD or ribbon near the plant to deter the birds.
You can make your Marigold happy by providing proper dry conditions, weeding, and tilling the garden after every winter.
But, when it doesn’t work, use the appropriate chemical, organic or biological treatments mentioned above in the guide.