6 Reasons Your Garden Needs Marigolds (The Ultimate Companion Plant)

orange and yellow french marigold flowers

Marigolds are beautiful flowers with many benefits. Therefore, planting them in your garden is ideal and even encouraged for the most abundant plant growth. So why should you plant them in your garden?

You should plant marigolds in your garden because they’re low-maintenance, all-purpose flowers with many benefits. Marigolds attract beneficial insects that repel pests, deter soil parasites, and make excellent cut flowers. They come in various colors, heights, and bloom shapes to suit any garden. 

There are various benefits to marigolds, both to you and to the other plants or vegetables in your garden. If you want to learn more about them, as well as where and how to plant marigolds in your garden, continue reading.

1. Marigolds attract beneficial insects to your garden

The main (and arguably, the most important) benefit of marigolds is their ability to attract valuable insects to your garden to eliminate harmful pests. Several harmful insects can negatively affect the plants in your garden, some of which include but aren’t limited to:

  • Aphids
  • Tomato hornworms
  • Cabbage worms
  • Beetle larva
  • Spider mites
tomato hornworms on wooden table
I obviously didn’t plant enough marigolds this season! At least my toddler gets something out of finding hornworms in the garden.

Marigolds attract helpful insects that eat or deter the harmful ones, protecting the other plants in your garden. Some insects that love marigolds and are great garden protectors include:

  • Lady bugs: feed on aphids, spider mites, and beetle larvae.
  • Praying mantis: feed on aphids, beetles, and mosquitoes.
  • Pirate bugs: feed on spider mites, corn worms, aphids, and insect eggs.

Having the beneficial bugs in your garden to take care of the potentially harmful ones is more ideal than using a pesticide, as natural, organic growing methods and materials are best.

2. Marigolds eliminate harmful nematodes in your garden

Nematodes are nearly invisible worms that can be parasites to your crops. While not all nematodes are parasitic, several can ruin your crops – especially the root-knot, lesion, and cyst nematodes. These pests are responsible for billions of dollars worth of crop losses every year.

Marigolds release a natural chemical called thiophene, which works as a nematode repellent. In fact, French and African marigolds have been shown to be completely devoid of root-knot nematodes, one of the most harmful nematodes. They can also effectively suppress the growth and spread of nematodes. 

Therefore, if you have crops in your garden, I would definitely recommend adding marigolds as a companion plant in order to eliminate any possible harmful nematodes. Strategically growing marigolds around the crops you want to protect will prevent nematodes from invading your garden.

3. Marigolds are excellent companion plants

As mentioned, marigolds excel as companion plants because of their nematode-resistant and suppression properties. However, some plants reap the benefits of marigolds more than others, including:

white marigold and red zinnia
Marigolds and zinnias are planted with tomatoes in my garden to attract pollinators and beneficial insects.
  • Tomatoes: Marigolds protect tomatoes from harmful tomato hornworms, which kill tomato plants.
  • Potatoes: Marigolds attract parasitic wasps, which will kill potato-eating worms – therefore protecting your potato plants.
  • Pumpkins: Root-knot nematodes commonly harm pumpkin crops, and marigolds will help keep these harmful parasites away.
  • Melons: Marigolds keep away harmful nematodes that often feed on melons.
  • Lettuce: Pests that typically feed on lettuce include aphids, beetles, and slugs – all of which are repelled by marigolds or eaten by beneficial predatory insects attracted to marigolds.
  • Cabbage: Marigolds repel cabbage moths, which commonly harm cabbage plants.

Therefore, planting marigolds in and around your vegetable garden will likely allow your crops to produce more and stay healthy. One of my favorite gardening books is Plant Partners, which digs into the science behind companion planting.

My favorite flower gardening books

  • If you’re new to cut flower gardening, Floret Farm’s Cut Flower Garden should be first on your reading list. Plant profiles, seasonal tasks, and arrangement tutorials will get anyone started with growing their own bouquets.
  • Vegetables Love Flowers will show you how effective companion planting can be for adding plant diversity, attracting pollinators and birds, and squeezing a few more plants into your garden space. 

4. Marigolds give your garden more variety

You should plant marigolds in your garden to add a pop of color. If you’re already looking for flowers to add to your garden, going with marigolds is an excellent idea due to their additional benefits.

Some colors you can expect to find from marigolds include:

  • Orange
  • Gold
  • Yellow
  • Red
  • Mahogany

However, not all marigolds will be solid colors, as some can have darker highlights along the outside edge of the petals. Many gardeners find such patterns more appealing.

marigold and calendula in soil blocks
Starting your own marigolds (and calendulas!) from seed will open the doors to many more varieties than what you typically find at a nursery or garden center.

There are many varieties of marigolds, but the three most common are French marigolds, African marigolds, and Signet marigolds.

African Marigolds

If you’re looking for larger plants to add to your garden, you should go with African marigolds. These flowers can grow up to four feet (1.2 m) tall and are the most extensive marigold variety you can find.

They produce large, double flowers that can be up to five inches (12.7 cm) wide. So, growing these large, colorful flowers will add a decorative look to your garden while also protecting it.

French Marigolds

French marigolds are smaller than African marigolds but can still reach up to a foot (30 cm) tall. These are slightly different from African marigolds, as they have two varieties – single and double. The double variety can bloom up to two inches (5 cm) wide. 

Therefore, these are an excellent option for a less intense flower to add to your garden.

Signet Marigolds

The Signet marigolds are the smallest type of marigold – only growing approximately six inches (15 cm) tall. In some cases, they can reach up to 12 inches (30 cm) tall.

They only have single-row petals that grow around one inch (2.5 cm) wide. Additionally, these marigolds have the added benefit of being edible, so you can add these to garnish your food or top your salad.

5. Marigolds are easy to grow

Having extra plants in your garden that add some variety and are easy to care for is ideal, and marigolds are one of them. 

Marigolds only really require full sun throughout the day, and they’re easy-going plants otherwise. They don’t need much water, and they’re tolerant of pests, heat, and drought. However, there are some essential care tips to keep in mind when it comes to caring for marigolds in your garden:

  • Plant your marigolds under full sun. The only strict requirement of marigolds is their need for full sun for most of the day. So when you plant them, ensure they’re planted in an ideal area that’s free from shade from the morning sun.
  • Allow the soil to dry between watering. Marigolds are drought-tolerant and will still survive even if they’re not watered frequently. Ideally, you should wait until the soil’s upper 2 inches (5 cm) is mostly dry before watering again.
  • Deadhead spent flowers to revitalize your plant. Deadheading marigolds is another care tip, although it’s not absolutely necessary. If you have marigolds that aren’t blooming as profusely as before, deadheading helps encourage more healthy blooms.

6. Marigolds make excellent cut flowers

If you enjoy flower arranging or just like having decorative flowers around the house, planting marigolds in your garden is a good idea. Marigolds add a pop of color that not many flowers can do, making them perfect for flower arrangements.

mariolds in bouquet under tree
Marigolds will easily last a week in the vase, and you can plant a few different varieties for a big range of colors.

As cut flowers, marigolds can last a week or more when cared for properly. So, when using them in arrangements, it’s essential to keep them away from things that can cause them to wilt early, such as excessive heat or strong drafts.

To harvest marigolds as cut flowers, follow these steps:

  1. Pick marigolds that are in full bloom but not too old. The trick is to catch the marigold flowers just after they have opened but before they have been pollinated so they last the longest.
  2. Cut the stem at a 45 degree angle to maximize surface area for drawing up water.
  3. Strip the foliage. It’s essential to strip all of the foliage off the stems. Any submerged leaves will encourage bacterial growth in the water, shortening the vase life of your flowers.
  4. Place the marigolds in tepid or warm water. To make the flowers last longer, consider adding a floral preservative to the water.

After arranging your marigolds, replace the water daily to prevent bacterial growth and put the vase out of direct sunlight.

Where should I put marigolds in my garden?

You should put marigolds in your garden where they’ll receive full sun for at least six hours daily. Additionally, if you have pest problems with crops in your garden, putting marigolds near or around the crops will keep the harmful insects away.

Marigolds are typically easy to grow and care for as long as they receive adequate sunlight daily. Therefore, where you plant them is a crucial decision.

If you plan on adding them to your garden to repel harmful insects from your other plants, you should put marigolds in the spaces between the crops you wish to protect. You can also add a protective line of marigolds around your entire garden if you want an added layer of protection.

You can see a sample layout of using marigolds as protective companion plants in this article: How Close Is Too Close For Companion Planting? (Sample Layouts).

How many marigolds do I need in my garden?

The number of marigolds you need in your garden depends on the size of your garden and the size of the marigold variety. African marigolds tend to spread up to 2 feet (60 cm), reducing the number of plants you’ll need around your garden for border purposes.

For instance, to fill a 4-foot (1.2-meter) side of your garden’s border, you can grow 3-4 African marigolds one foot (30 cm) apart. In contrast, the same border will require 6-8 Signet marigolds grown at least 6 inches (15 cm) apart.

If you want companions between other plants in your garden, you can choose the smaller marigold varieties like the Signet.

Learn more

Marigolds aren’t the only awesome companion plants you can grow each year. Some of my other favorites are zinnias and sunflowers, not to mention flowering herbs. Get inspired to plant with these articles:

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