With their bright, cheerful blooms, marigolds are a beloved annual flower for gardens worldwide. However, marigolds can encounter issues that lead to wilting, leaf loss, lack of flowers, and even plant death. If your once-thriving marigolds are struggling, don’t give up hope! This article covers the most common reasons marigolds die or decline and how to get them thriving once again.
Overwatering
Excess moisture is one of the quickest ways to kill marigolds As plants native to sunny Mexico, marigolds despise soggy soil Overwatering causes root rot which makes roots turn brown and mushy, unable to take up nutrients and water.
Signs of overwatering
- Wilting leaves and stems
- Yellow, dropped lower leaves
- Foul odor from soil
- Mushy or blackened roots
Fixes for Overwatering
- Allow soil to dry out completely before watering again
- Remove rotten roots and repot in fresh, well-draining soil
- Water less frequently, allowing soil to partially dry out between waterings
- Add sand or perlite to improve drainage
Underwatering
While marigolds don’t like soggy soil, allowing them to dry out too much can also cause decline. If soil gets bone dry, plants become stressed and leaves wilt and turn brown. Prolonged droughts can be fatal.
Signs of underwatering:
- Dry, cracked soil
- Wilt that doesn’t recover after watering
- Curled, crispy leaves
- Stunted growth
Fixes for Underwatering
- Water plants deeply right away if dry
- Check soil frequently and water when just the top inch becomes dry
- Use mulch to retain moisture longer
- Group pots together to create a more humid microclimate
Aim for about 1 inch of water per week, adjusting for weather, plant size, and soil type.
Insufficient Sunlight
As sun-loving plants, marigolds need at least 6 hours of direct sunlight daily. Too much shade results in leggy, weak plants with few flowers. Low light keeps them from properly photosynthesizing.
Signs of insufficient sunlight:
- Tall, sparse growth
- Smaller flowers
- Lower flower production
- Paler leaf color
Fixes for Insufficient Sunlight
- Move marigolds to the sunniest spot possible
- Supplement with grow lights if needed
- Reflect light onto plants with white boards or foil
- Replace with partial shade plants if sunlight can’t be improved
Morning sun is ideal. Provide afternoon shade in hot climates to prevent stress.
Extreme Temperatures
Marigolds thrive in warm weather but suffer below 50°F or above 90°F. Exposure to temperature extremes causes stress, yellowing leaves, slowed growth, and flower loss.
Signs of temperature stress:
- Wilting on hot days
- Yellow lower leaves
- Leggy growth
- Loss of bloom
- Wilt despite adequate water
Fixes for Temperature Stress
- Move pots to sheltered areas away from hot sun
- Provide shade cloth over plants during heat waves
- Insulate pots in winter with straw or burlap
- Bring containers indoors if overnight frost is predicted
- Choose more heat/cold tolerant varieties
Provide consistent temperatures between 60-75°F for best growth.
Insect Pests
Marigolds attract beneficial insects but also fall prey to pests like aphids, Japanese beetles, and spider mites. Pests suck nutrients, spread disease, and damage flowers.
Signs of insect pests:
- Speckled, stippled or curled leaves
- White spots or webbing
- Holes in leaves and flowers
- Distorted buds
- Sticky residue on plants
Fixes for Insect Pests
- Manually remove pests
- Use insecticidal soap, neem oil, or pyrethrins
- Attract beneficial insects like ladybugs or lacewings
- Cover plants with row cover fabric
- Remove badly infested plants immediately
Check for pests frequently and treat early before they multiply.
Diseases
Marigolds are prone to fungal diseases like powdery mildew, blights, and rots. Viruses like aster yellows also cause decline. Diseases disfigure plants, create spots, and spread quickly.
Signs of diseases:
- White powdery film on leaves
- Yellow mottling
- Stunted growth
- Brown blotches
- Wilting despite watering
- Blackened roots or stems
Fixes for Diseases
- Improve air circulation between plants
- Treat powdery mildew with neem oil
- Apply copper fungicide for leaf spots
- Remove and destroy infected plants
- Space plants further apart to prevent spread
Keep foliage dry to prevent disease and prune off affected parts promptly.
Improper Soil
Marigolds need well-drained, fertile soil with a pH between 6-7.5. Poor quality soil leads to stunted, yellowing plants with few blooms.
Signs of improper soil:
- Yellowing leaves
- Poor growth
- Low flower production
- Wilting
- Brown leaf tips
Fixes for Improper Soil
- Test soil pH and amend accordingly
- Improve drainage by mixing in compost or perlite
- Add organic matter like compost to nutrient-deficient soil
- Fertilize monthly with a balanced flower fertilizer
- Repot in quality potting mix annually
Marigolds thrive in average garden soil. Enrich soil with compost or manure before planting.
Environmental Changes
Marigolds dislike sudden changes in light levels, temperatures, or soil moisture. Disruption causes stress which manifests as yellowing, wilting, shock, and dieback.
Signs of environmental stress:
- Yellowed lower leaves
- Leaf drop
- Failure to bloom
- Dieback
- Stunted growth
Fixes for Environmental Stress
- Acclimate plants slowly to any changes
- Provide consistent watering, temperatures, and light
- Avoid disturbing or transplanting during bloom
- Shelter plants from strong winds and weather shifts
- Stake tall plants to prevent damage
Minimize stress by keeping marigolds in the optimal conditions consistently.
With attentive care and prompt treatment of any issues, marigolds will provide non-stop color all season long. Monitor plants frequently for early signs of problems. Address problems quickly before they escalate and spread. With proper care tailored to their needs, marigolds will thrive season after season, lighting up your garden with their lively, vibrant presence.
Brown Spots or Leaf Tips
Brown spots can be caused by bacterial leaf spot, or an excessive amount of iron. Marigolds do not grow well in soils that have low pH, and this can lead to iron toxicity. A soil test can help determine if you have a low soil pH.
If the spots seem more sporadically located, they are likely caused by bacterial leaf spot. Treat leaf spot with a fungicide.
Plants become leggy when they aren’t getting enough sunlight. Marigolds grow best in areas that receive full sun, as much as they can get. If your plants are in a spot that doesn’t get enough sunlight or too much shade, they will get tall and look stretched out as they try to get more light.
Be sure to rotate containerized plants to ensure they receive even sunlight. Transplant-shaded plants into a new sunnier location and they will soon adjust to normal growing patterns.
Powdery Mildew can grow when there is a lot of humidity or when plant leaves aren’t allowed to dry out and get enough air flow. Powdery Mildew is a fungus that appears as a sticky white substance on the tops of leaves.
It happens most often on older growth with leaves that are bushy and close together, but in some cases it can also happen on new growth. You need to get rid of this fungus right away because it can hurt the host plant and spread to your other plants.
You can stop Powdery Mildew from spreading with some home remedies, but if it gets really bad, you might need to use a fungicide. Copper soap or fungicides with sulfur as an ingredient seem to be the most effective.
Yellow or brown speckling on leaves is usually caused by a bug infestation. Aphids or spider mites are usually the culprits on flowering annuals such as marigolds. Aphids appear as tiny green insects on the undersides and stems of plants.
They feed on foliage, creating a brown speckled appearance. Because aphids live for such a long time, it is important to get rid of them before they get out of hand.
Spider mites are tiny white bugs that will create small webs that look similar to normal spider webs. They make a sticky substance that covers the plant and eat the leaves, which makes the leaves light yellow. Spider mite infestations start small but can increase quickly. Pyrethrum sprays are a good option for eradicating spider mites.
Floppy Stems or Leaves
The most common reason plants become floppy or lose their turgidity is from overwatering. If you don’t let plants dry out between waterings, they can get waterlogged, which makes the stems look limp and sometimes makes them lean or fall over.
These floppy stems can hinder the plant from taking up moisture and nutrients properly. Most plants will bounce back from this if given time to adjust. Allow your marigolds to dry out in between waterings to prevent overwatering.
Plants that are not producing flowers usually means they aren’t getting enough sunlight. Marigolds are full sun plants and will take all the sunlight they can get. If your plants aren’t able to flower because they are in the shade or because of other plants or trees nearby, If your plants are receiving too much shade, move them to a sunnier location.
If your plants are getting a lot of sun but still aren’t flowering, you might want to remove the spent flowers. This can promote new growth and will help the plant produce new flowers.
Young plants will not flower until they reach a certain maturity. If you transplant young plants, give them some time to adjust to their new area and mature. If planted in the right conditions, they should flower in no time!.
Plant leaves turn purple for a couple of reasons. The leading cause is usually a phosphorous deficiency. Marigolds don’t need a lot of nutrients or fertilizer, but they may need more phosphorus depending on the soil and other things in the area.
Low night temperatures can also cause leaves to turn purple. If temperatures dip below 55, your plants can react in many ways. One way is that the leaves will start to turn purple.
If you suspect phosphorus deficiency, apply a fertilizer to your plants. A low grade all purpose should do the trick if you haven’t fertilized recently or at all. If you have been fertilizing your plants, you might want to try a different one or look for one that has a lot of phosphorus in it.
Leaves turning yellow can be caused by a few different things. Lack of nutrients could be one reason your marigold leaves are turning yellow. Applying a fertilizer will help the coloration go back to normal.
Leaves can also turn yellow due to a disease called Aster Yellows. Aster Yellows hurt plants in the Asteraceae family by stopping their growth and turning their leaves yellow. They can also damage buds and blooms.
This disease is spread by insects that can be found on your plants or weeds surrounding the area. Keep the planting area weed free and keep an eye out for insects all season.
Marigolds do not like to be kept in moist conditions. If you let your plant dry out between waterings, you can keep problems like stem and root rot from happening.
If your plant’s stems are turning brown, this can be a sign they are rotting. Most of the time, the rot starts in the roots, where too much water is being held. It then moves up the plant, starting with the main stem and continuing up.
You can help keep this from killing your plants by using a fungicide, but if the problem has already spread to a lot of the plant, it may be too late. Make sure you’re planting in fresh, healthy soil to help prevent this problem from occurring.
What’s eating my MARIGOLDS??
FAQ
How to revive a dying marigold?
What do overwatered marigolds look like?
Why are my marigolds shriveling up and dying?
Why are my marigolds turning brown and dying?
What happens if a marigold plant dies?
The color of the Marigold leaves can fade and eventually pale and wilt. Since the fungus attacks the roots, plant growth usually stops, and Marigolds can eventually die. Solution – Remove them from your garden immediately if you find affected plants.
Do marigolds have diseases?
Marigolds are common companion plants that are seen to repel many pests. They are resistant to pest problems, but diseases in Marigold plants are sometimes a problem. The most frequently found diseases are fungi which affect the stems, leaves, and roots. However, diagnosis and treatment of Marigold plant diseases are relatively easy.
Why are my marigolds wilting?
If you keep your plants too moist, especially marigolds that don’t like to be kept moist, you can stress your plant out further. Plants will also show signs of wilting when they are experiencing heat stress. This usually occurs in the warmer summer months and has almost nothing to do with moisture.
Why are my marigolds not blooming?
Your marigolds do not bloom due to lack of sunlight. Plants that are not producing flowers usually means they aren’t getting enough sunlight. Marigolds are full sun plants and will take all the sunlight they can get. If your plants are getting too much shade due to location or surrounding plants or trees, this can hinder them from flowering.