Marigolds are one of gardeners favorite flowers. Their bright colors and the fact they can repel pests make them extra popular.
On top of that they’re easy to grow and very versatile, so are a perfect choice for beginners.
But not every plant makes a good neighbor for marigolds. Some will clash and compete for resources, attract pests or just don’t grow well alongside them.
So here’s some of the worst plants that don’t work well with marigolds, and the reasons why, that you can avoid planting.
Why Plant Compatibility Matters
In gardening it’s really important to get the right plants that work and grow together. If not you’ll end up with an unhealthy and failing garden.
The truth is that certain plants work together and others don’t. And the ones that do work by enhancing each other’s growth and protecting one another from pests.
The wrong combinations can cause problems though. Poor pairings can lead to nutrient competition, reduced growth and pest infestations that will affect your plants overall health.
To make the most of your marigolds it’s definitely worth knowing which plants to keep at a distance. So use these recommendations of which ones to avoid.
1. Beans
Beans and marigolds might seem like a harmless combination but they can negatively impact each other.
Why Beans are a Problem:
- Root Competition: Both plants have extensive root systems that compete for space and nutrients.
- Allelopathy: Marigold roots can release compounds that inhibit bean growth.
- Pest Concerns: Beans attract aphids, which may also damage marigolds.
- Fungal Issues: Beans are susceptible to fungal diseases that can spread to marigolds.
- Shading Problems: Climbing beans can overshadow marigolds, limiting their sunlight.
- Different Water Needs: Beans prefer consistent moisture, while marigolds tolerate drier conditions.
- Stunted Growth: The competition for phosphorus can lead to poor yields for both plants.
- Pest Cycle Impact: Marigolds attract beetles that might harm bean crops.
- Soil Imbalance: Bean plants fix nitrogen, which may not align with marigold nutrient requirements.
- Poor Pollination: The presence of marigolds might distract pollinators away from bean flowers.
2. Cabbage Family
Cabbage, broccoli, kale and other brassicas don’t thrive near marigolds.
Why Brassicas are a Problem:
- Nutrient Competition: Both are heavy feeders, depleting essential soil nutrients.
- Pest Attraction: Marigolds attract pests like slugs that are damaging to brassicas.
- Allelopathy: Marigolds can release chemicals that inhibit brassica growth.
- Root Zone Conflict: Their overlapping root systems compete for space and nutrients.
- Fungal Diseases: Brassicas are prone to fungal issues that may spread to marigolds.
- Moisture Imbalance: Brassicas prefer more consistent watering than marigolds.
- Weed-Like Growth: Marigold roots can act invasively, stunting brassica growth.
- Insect Confusion: Pests repelled by marigolds may seek refuge on brassicas instead.
- Crowding Issues: The leafy growth of brassicas can overshadow marigolds.
- Different Soil Needs: Brassicas prefer alkaline soil, while marigolds thrive in neutral to acidic soil.
3. Fennel
Fennel is notorious for being an unfriendly companion to many plants, marigolds included.
Why Fennel is a Problem:
- Allelopathy: Fennel releases chemicals that inhibit nearby plant growth.
- Nutrient Competition: Fennel depletes essential nutrients, leaving marigolds struggling.
- Pest Habitat: Fennel attracts pests that may target marigolds.
- Shading Issues: Fennel grows tall, overshadowing marigolds and reducing sunlight access.
- Root Spread: Fennel’s invasive root system competes aggressively with marigolds.
- Moisture Competition: Fennel absorbs significant amounts of water, drying out the soil.
- Delayed Growth: Nearby marigolds may show stunted or slowed development.
- Attracting Aphids: Fennel attracts aphids, a common garden pest.
- Unbalanced Ecosystem: Fennel’s attractants can disrupt the balance of beneficial insects.
- Soil Toxicity: Fennel compounds may linger in the soil, affecting marigold growth even after removal.
4. Potatoes
Potatoes don’t get along well with marigolds (and many others!) due to their pest problems and nutrient needs.
Why Potatoes are a Problem:
- Pest Attraction: Potatoes attract pests like aphids and Colorado potato beetles that can spread to marigolds.
- Nutrient Depletion: Potatoes are heavy feeders, competing for nitrogen and potassium.
- Shading: Potato plants grow bushy, potentially blocking sunlight from marigolds.
- Moisture Issues: Potatoes require more consistent watering than marigolds.
- Soil Disturbance: Harvesting potatoes can disrupt marigold root systems.
- Fungal Concerns: Potatoes are prone to blight, which can spread to nearby plants.
- Root Zone Conflict: Their root systems overlap, leading to poor growth for both plants.
- Limited Pollinators: Pollinators may prioritize marigolds over potato flowers.
- Weed Growth: Potatoes create dense foliage, encouraging weeds to sprout around marigolds.
- Harvest Impact: Digging up potatoes can disturb marigold roots.
5. Dill
Dill may seem like a harmless herb but it also clashes with marigolds.
Why Dill is a Problem:
- Allelopathy: Dill releases chemicals that can stunt marigold growth.
- Pest Attraction: Dill attracts pests that may migrate to marigolds.
- Nutrient Competition: Dill competes for nitrogen, leaving the soil deficient.
- Root Overlap: Their root systems can tangle, hindering growth.
- Shading Effects: Dill grows tall, blocking sunlight from shorter marigolds.
- Different Water Needs: Dill prefers more moisture than marigolds.
- Disrupted Ecosystem: Dill may repel beneficial insects that marigolds attract.
- Crowding: Dill spreads quickly, overwhelming marigold space.
- Weed-Like Behavior: Dill’s invasive growth pattern can choke out marigolds.
- Harvesting Issues: Removing dill can disturb marigold roots.
Good Companions for Marigolds
While some plants are problematic others pair perfectly with marigolds:
- Tomatoes: Marigolds repel nematodes and aphids that harm tomatoes.
- Basil: Basil benefits from marigolds’ pest-repelling properties.
- Lettuce: Marigolds keep lettuce pest-free.
- Carrots: Marigolds repel carrot flies.
- Peppers: Marigolds deter pests that target peppers.
- Zinnias: Both attract pollinators.
- Cucumbers: Marigolds help repel cucumber beetles.
- Eggplant: Marigolds deter pests harmful to eggplants.
- Strawberries: They attract pollinators that help strawberries thrive.
- Squash: Marigolds repel squash beetles.
Tips for Companion Planting with Marigolds
- Test your soil for nutrient levels to match compatible plants.
- Group plants with similar watering needs.
- Rotate crops annually to prevent pest buildup.
- Space plants adequately to reduce competition.
- Use mulch to manage weeds and conserve moisture.
- Plant marigolds along garden edges for pest control.
- Observe plant health and adjust pairings as needed.
- Encourage beneficial insects with diverse plantings.
- Keep a gardening journal to track successful combinations.
- Experiment with different arrangements to find what works best.
As long as you plant wisely your marigolds will happily thrive and do well alongside the right companions.