8 Benefits of Marigolds as a Companion Plant

Companion planting isn't just a trend; it's an age-old garden hack that savvy gardeners around the globe have been tapping into for centuries. Among the myriad of companion plants, marigolds stand out for their versatility and effectiveness. I typically have a marigold plant in every one of my garden beds and even in containers near my container systems.

So, why are marigolds such a big deal? In this blog post, we're diving deep into world of marigolds and uncovering all the incredible ways they can transform your vegetable garden. From fighting off pesky invaders without using harsh chemicals to giving a boost to your veggies' growth, marigolds do it all with flair.

Types of Marigolds

Marigolds, those bright and cheerful members of the Tagetes genus, hail from the Americas and have been brightening gardens with their ornamental beauty and medicinal benefits for ages. You've probably seen the popular varieties around – the petite French marigolds (Tagetes patula), the grand African marigolds (Tagetes erecta), and the dainty signet marigolds (Tagetes tenuifolia), each with their own unique splash of color and distinctive aroma. Known for their vibrant colors and distinctive scent, marigolds possess several characteristics that make them excellent companion plants.

1. Marigolds as a Pest Deterrent

One of the most well-known benefits of marigolds is their ability to repel pests naturally. Compounds found in marigold emit a strong aroma that deters aphids, whiteflies, squash bugs and even rabbits.  

Planting marigolds alongside susceptible crops can help protect them from infestation, reducing the need for chemical pesticides. Studies have shown that planting marigolds among your veggies, known as intercropping, can significantly decrease pest damage, making them invaluable allies in organic gardening practices. For rabbit control, you need to grow a continuous wall of odiferous plants like marigolds for them to work.

2. Natural Mosquito Repellent

In addition to other pests, the strong aroma of marigolds also wards off mosquitoes. As a mosquito magnet, gardening especially early in the morning or at dusk can be especially problematic, so anything natural that I can plant to ward off these blood-suckers, I’m willing to try.

Other plants that keep them away include lavender, lemongrass, catmint and regular mint, sage, onions and chives, rosemary, bee balm, and citronella. Honestly, I have almost all of these in my garden right now and I still get eaten by mosquitoes, so I think for this to have an apparent effect you need A LOT of these plants not onesie-twosies.

3. Nematode Control Properties of Marigolds

These plants act as biofumigants, releasing compounds from their roots that suppress nematodes, including root-knot nematodes. To get the most benefit, plant French or African marigolds (Tagetes spp.) densely as a cover crop then place tomatoes in the same spot as some of the marigolds.

4. Marigolds and Beneficial Insects

While marigolds repel harmful pests, they also attract beneficial insects like ladybugs, parasitic wasps, and hoverflies, which prey on garden pests. Their bright, aromatic flowers serve as a valuable food source for pollinators such as bees and butterflies, promoting biodiversity and ecosystem balance in the garden. By incorporating marigolds into garden designs, gardeners can cultivate a thriving ecosystem that supports both plant and animal life.

5. Marigolds as a Trap Crop

Not only do marigolds repel certain pests, they can attract some, so how can we use this to our advantage? Marigolds serve as a trap crop for spider mites, thrips, snails, and slugs. As a trap crop, marigolds are much more attractive than the food crop, so they may stay on the plant. You can plant marigolds around the perimeter to be your first defense against these pests.

Marigolds are also a food source for predatory mites which may be attracted naturally or supplemented. Predatory mites such as Amblyseius swirskii or Neoseiulus californicus can be purchased and added to plants with spider mites or thrips. If there is a marigold close by (and I mean really close), they will go to the marigold for pollen where they will reproduce and sustain their population. Some have called this a guardian plant when used this way.

If slugs are eating your marigolds, this is an indicator that you need to manage them. Refer to blog post on Eco-Friendly Ways to Manage Slugs and Snails for effective strategies.

6. Soil Improvement Benefits of Marigolds

Beyond pest control, marigolds offer soil improvement benefits that contribute to overall garden health. Their extensive root systems also help break up compacted soil and improve drainage, creating optimal growing conditions for neighboring plants.

7. Ground Cover Functionality of Marigolds

With their striking yellow and orange blooms, marigolds make a striking ground cover. Marigolds can grow densely so they cover bare soil, reducing erosion and water loss. Since they are low-growing, they can serve as an understory for garden beds and fill in gaps.

8. Weed Suppression

They also reduce weeds from invading by outcompeting them. Depending on the amount of space they have and their variety, they can spread out by laying a carpet down preventing weeds from coming in.

Companion Planting Combinations with Marigolds

Marigolds complement a wide range of companion plants, enhancing their growth and resilience. They pair particularly well with tomatoes, peppers, eggplants, and cucurbits, providing natural protection against pests like aphids and nematodes.

Interplanting marigolds with herbs such as basil and parsley can improve herb flavor and deter pests simultaneously. Strategic placement of marigolds throughout the garden can create a dynamic ecosystem where plants support each other's growth and vitality.

Using Marigolds in Different Garden Settings

Whether you have a vegetable garden, flower beds, or container gardens, marigolds can find a place in your gardening endeavors. In vegetable gardens, intercropping marigolds with susceptible crops can improve yields and reduce pest damage. In flower beds, marigolds add a splash of color and fragrance while deterring harmful pests. Even in container gardens, compact varieties of marigolds thrive and provide pest protection in limited spaces.

Tips for Growing Marigolds Successfully

To harness the full potential of marigolds as companion plants, it's essential to provide them with the right growing conditions. Marigolds thrive in well-draining soil and full sun, so choose a sunny spot in your garden for planting. Water consistently, keeping the soil evenly moist but not waterlogged. Deadhead spent flowers to encourage continuous blooming and fertilize sparingly to avoid excessive foliage growth. With proper care, marigolds will reward you with vibrant blooms and valuable pest control benefits throughout the growing season.

As a fun tip, marigolds are prolific seeders. Once you deadhead the bloom, let it dry and remove the seeds for the next season.

Common Myths and Misconceptions about Marigolds

Despite their numerous benefits, marigolds are sometimes misunderstood in the gardening community. Contrary to popular belief, marigolds do not repel all pests, and their effectiveness may vary depending on the species and cultivar. Some of the newer hybrid marigolds have not retained the natural pest controlling scent.

Additionally, while marigolds can improve soil health, they are not a cure-all for soil problems and should be used in conjunction with other soil management practices for optimal results. By dispelling these myths, gardeners can better understand and appreciate the role of marigolds in sustainable gardening practices.

In conclusion, marigolds are not just pretty flowers—they're powerhouse companion plants that offer a myriad of benefits to the garden. From pest control to soil improvement and pollinator support, marigolds play a vital role in creating healthy, resilient ecosystems. By incorporating marigolds into your garden designs and companion planting schemes, you can reap the rewards of a thriving and sustainable garden for years to come. So next time you're planning your garden layout, don't forget to harness the power of marigolds!