Marigolds: The Ultimate Guide to Growing Vibrant Marigolds

By Gilmour

Bright and hardy marigolds are a no-fuss, low maintenance annual. Their cheery blooms thrive in the sun, making these summer-through-fall-time beauties a popular choice.

Read on to find out more about marigold plants.

• What are Marigolds?
• Popular Types of Marigolds
• How to Plant Marigold Flowers
• Growing and Caring for Marigold Flowers
• Common Questions About Growing Marigolds

What are Marigolds?

Marigolds have carnation or daisy-like flowers, usually in bright orange, copper brown or yellow that can grow as single blooms or in clusters. Their distinct smell is often described as pungent, but most gardeners appreciate this, as it keeps away garden pests and insects. However, keep an eye out for slugs and caterpillars as they can be issues for marigolds.

Popular Types of Marigolds

• French Marigolds – French marigolds are one of the most common varieties. They are easy to grow, top out at 6 – 12 inches tall and have a long growing season with blooms that last frost to frost. They are both deer resistant and drought tolerant. Plant French marigolds in well-drained soil in full sun.
• African Marigolds – The African marigold is also known as the Aztec or American marigold. It has large, bright blooms and grows taller than some other varieties. At 1 – 3 feet tall, the African marigold is deer resistant and sure to be a showstopper. They do best in well-drained soil that can dry out between watering, as they are susceptible to soil-born funguses and rot.
• Mexican Marigolds – The Mexican marigold has a wider, flat flower and aromatic foliage. It grows 4 – 6 feet tall and attracts bees and butterflies with its musky scent. It grows well in full sun and well-drained soil. Mexican marigolds are deer resistant and drought tolerant, but will perform better with regular, consistent irrigation. One of the only perennial marigolds.
• Triploid Marigolds – A hybrid between French and African marigolds, triploid marigolds also have large, sturdy blooms. They have low germination, which can make them a bit challenging to grow, but with proper care can be the most rewarding, as they have a longer growing season than some other types. Triploid marigolds do well in extreme heat and are much more day length neutral than other marigolds, meaning they will flower even if they don’t get a lot of light.
• Signet Marigolds – These pretty, delicate little marigolds are actually edible, and their sweetness can brighten up any summer salad with a pop of unexpected color. They need full sun and moist, but not rich or fertile, soil to do well.

How to Plant Marigold Flowers

Marigolds are easy to plant and can do well in virtually any type of soil. Most types like full sun and can withstand even extremely hot temperatures, making them one of the easiest flowers to grow all year long. In fact, their hardiness makes it unnecessary to start marigold seeds indoors. Below is a simple guide to planting seeds directly in the ground – or transplant – whichever you prefer.

• For large varieties: sow seeds 18 to 24 inches apart
• For medium varieties: space 12 to 15 inches apart
• For dwarf plants: space 6 inches apart

Simply cover the seeds with soil and keep them moist and warm. If transplanting, be sure to water well after doing so. Plants will sprout in a few days if the weather is warm enough, and blooms will appear in around 2 months.

When should you plant marigolds?

Plant your marigolds in the spring, after the last frost. If you choose to start from seed indoors, you can begin the process about 2 months before the last expected frost. Seeds will germinate anywhere from 4 to 14 days in warm soil that has an average temperature of 70°F – 75°F. Above the refrigerator is a good spot for seeds to rest if you are germinating indoors. In this case, once the seeds germinate, transplant them outdoors after the last frost.

How to transplant marigolds from seed

After seeds have germinated, moisten soil and then plant seedlings about 1 inch apart from one another.

How to thin seedlings

If planting seeds directly in the ground without germinating, once sprouted, but while still small, thin your seedlings. Thinning seedlings is important so that maturing plants have plenty of space to grow without having to compete for nutrients and water. It also helps improve air circulation. To thin, carefully remove a seedling and, holding it by its leaves to prevent the stem from being crushed, lightly set the roots into a hole. Pat the soil around the stem gently but firmly. Spacing will depend on the variety.

Planting in containers

Be sure to use a large enough container because marigolds tend to grow quickly, and crowding can be an issue.

Use a soil-based potting mix and either add in a granular, slow-acting fertilizer at the time of planting, or periodically water with a diluted liquid fertilizer. Do not over-fertilize.

Tips to Care for Marigold Flowers

Marigolds establish easily, and new blooms will appear not long after planting. These low-maintenance plants do not require much care, and with just a few tips, will put on a showy display for months.

Tip 1. Water regularly, but not too frequently. Let soil dry out in between watering, and then water well each time. If it is an extremely hot period, it’s fine to increase the frequency, just take care not to overwater.

Tip 2. Never water overhead. Too much water on marigold leaves can result in a powdery mildew building up on the pretty dark green foliage. Water at the base of the plant to avoid this.

Tip 3. Deadhead as needed. Marigolds actually do not need a lot of deadheading but doing so will promote more blooms. To deadhead, simply remove any dying blossoms.

Tip 4. Pinch back. Pinching from the top of the plant is an easy way to remove dead blooms and encourage growth while helping plants fill out so they don’t become leggy. Using your thumb and forefinger, simply pinch the dead bloom where it meets the stem. Pinching can trick plants into producing more because you remove the bloom before it goes to seed, which essentially is what tells the plant to stop producing.

Tip 5. Do not fertilize during the growing season. Fertilizer will result in pretty foliage, but it will be at the expense of your blooms.

Tip 6. Add mulch. Mulch will prevent weeds from growing and keep soil nice and moist.

Common Questions About Growing Marigolds

In addition to being easy to grow, marigolds also make great companion plants in the garden. Learning everything you can about them helps ensure they will grow big and beautifully for your enjoyment.

How do you reseed marigolds?

To reseed marigolds, wait for the plant to begin to dry out. When the petals are brown, and the plant base is just starting to turn brown, you can harvest the seeds. Do not wait for the entire plant to turn brown or you risk it molding.

Do marigolds spread?

Marigolds are rapidly growing plants and most varieties are self-seeding, which means they will drop seeds and spread throughout your yard or garden. Limit the ability to self-seed by deadheading before blooms go to seed.

Are marigolds perennials or annuals?

Actually, both! Most marigolds are annuals, but a few are perennials. Marigolds self-seed so they may appear to be a perennial when in reality, they are just coming back from seed.

What zone do marigolds grow best in?

Marigolds grow well in planting zones 2 – 11, and they do best in warmer months. They will have a longer blooming season in zones 10 or higher, where temperatures don’t dip close to freezing, even later in the winter.

Why are my marigolds dying?

Marigolds are a fairly easy plant to grow, but that doesn’t mean they can’t have issues. If your marigolds are not doing well, it may be due to slugs or caterpillars. If you see small, chewed edges or holes in the leaves, check your plants for caterpillars. Removing them by hand is simple, fast and can alleviate the problem.

Do marigolds bloom year-round?

Marigolds do not bloom year-round, but with proper care, some varieties can bloom for several months. They will put on the best show all summer and into fall.

Marigolds are a hardy, bright, easy-to-grow plant. They are virtually fool-proof, so even first-time gardeners can trust their marigold show will be abundant and something to be proud of.