Though they are not native to Australia, marigold flowers have become a popular addition to many gardens down under.
These vibrant flowers are known for their ability to deter pests, making them a popular choice for organic gardeners.
In addition, marigolds are tolerant of poor soils and dry conditions, making them ideal for tropical climates.
If you’re thinking of adding marigold plants to your garden this year, here’s everything you need to know about growing them.
In many cultures, the marigold plant is associated with purity, healing, and protection.
The flowers are often used in religious ceremonies and rites of passage, and their bright colours make them a popular choice for decorating homes and altars.
In Hinduism, the marigold is a sacred flower that is often used in worship. It is believed to have the power to drive away evil spirits and protect the living from harm.
In Mexico, the marigold is known as the “flower of the dead,” and it plays an important role in the Day of the Dead celebrations.
The flowers are used to decorate altars and graves, and they are thought to guide the souls of the dead back to their families.
Common Marigold Varieties in Australia
Australia is home to several different species of marigolds, including the Mexican marigold (Tagetes erecta, also known as the African marigold), French marigold (Tagetes patula), and signet marigold (Tagetes tenuifolia).
Each of these plants has its own unique bloom, ranging in colour from deep yellow to scorching orange.
Mexican marigolds, also known as African marigolds (Tagetes erecta), are annuals that typically reach heights of around 60cm.
They are native to Mexico but have been naturalised in many other parts of the world.
The flowers can be orange, yellow, or red, and they typically bloom from summer to fall.
Mexican marigolds are also known for being fairly drought-tolerant, which makes them a popular choice for landscaping in dry climates.
French marigolds (Tagetes patula) are annual flowering plants that typically reach a height of 30-60cm.
They have bright green leaves and produce large, showy flowers in a variety of colours including yellow, orange, and red.
French marigolds are native to Mexico and Central America, but they have been cultivated worldwide for centuries.
They are tolerant of poor soil and adverse growing conditions, and they will bloom from spring until fall with proper deadheading.
Signet marigolds (Tagetes tenuifolia) are annual flowers that are often used in gardens. They are easy to grow and tolerate a variety of soils and weather conditions.
The flowers are small and daisy-like, with yellow or orange petals and a central disc. The leaves are lance-shaped and have a pungent, lemon-like scent.
Signet marigolds self-seed readily, so they can often be found growing in areas where they have not been planted.
When to Plant Marigolds
The best time to plant marigolds in Australia is in spring or early summer. This will give the plants plenty of time to establish themselves before the hot summer sun arrives.
Marigolds are not very frost-tolerant, so it is important to wait until the danger of frost has passed before planting them outdoors.
Where to Plant Marigolds
Marigolds are not fussy plants and will grow in most climates and soil types. When planting marigolds, it is important to choose a location that receives full sun.
They will also need well-drained soil in order to thrive. Marigolds can be planted directly in the ground or started in pots and then transplanted later on.
Starting with Marigold Seeds vs. Marigold Transplants
You can grow marigolds from either seeds or transplants.
If you choose to start with marigolds seeds, plant them indoors about 6-8 weeks before the last frost date.
Marigold transplants can be planted outdoors after the last frost date has passed.
The Best Ways to Grow Marigolds
- Marigold seeds
- Seed trays
- Seed-starting mix
- Potting soil
- Garden trowel
- Plastic wrap
- Watering can
- Spray bottle with water
How to Plant Marigolds from Seeds Indoors
- Prepare your seed trays and sow your marigold seeds — Fill a planting tray with moistened seed-starting mix. Sow the seeds thinly on the surface of the mix and press them gently into the soil.
- Mist your marigold seeds and let them germinate — Lightly press the seeds into the mix, then mist them with water. Cover the tray with plastic wrap or a lid to create a humid environment for germination.
- Place your seed trays in a sunny spot indoors — Place the trays in a warm, sunny spot and keep the soil moist. The seeds should germinate within 7-10 days.
- Transplant into individual pots and continue caring for your plants — Once the marigold seedlings are 5-10cm tall, transplant them into their own pots filled with potting soil. Give them plenty of sunlight and water regularly to let the marigolds bloom.
- Deadhead marigold plants — To deadhead a marigold plant, simply snip off the flower at the base of the stem. You can also cut back the entire stem if necessary. As you deadhead, be sure to keep an eye out for any green buds, as these will bloom in the coming days.
How to Grow Marigolds from Seeds Outdoors
- Choose the right location — Marigolds need full sun in order to thrive, so choose a spot in your garden that gets plenty of sunlight throughout the day. Once you have found the perfect spot, it’s time to prepare the soil.
- Prepare your soil — Marigolds prefer well-drained soil that is high in organic matter with a pH between 6.0 and 7.5. If your soil is heavy or clay-like, you may need to amend it with some sand or compost before planting. You can also improve drainage by growing them on raised beds or mounds.
- Plant your marigold seeds — Marigold seeds are small, so it’s best to sow them indoors about 6-8 weeks before the last frost date. This will give them a head start on the growing season. Follow steps 1-4 of growing marigolds indoors — plant the seeds in trays, mist and wait for 7-10 days, but don’t stop there. You’ll need to harden off your seedlings to prepare them for outdoor planting.
- Harden off your marigolds — Hardening off is the process of slowly acclimating plants to the outdoors. To harden off marigolds, start by placing them in a sheltered spot outside for a few hours each day. Gradually increase the time they spend outdoors and protect them from strong winds and direct sunlight. After two weeks, your plants should be ready to withstand anything.
- Transplant your marigolds outdoors — Gently dig holes for each plant that are twice as wide as the root ball and barely deeper than the height of the pot. Carefully remove each seedling from its pot along with its roots and transplant it into one of the prepared holes in your garden.
- Water regularly and carefully — Water each plant well after transplanting and monitor them for signs of stress such as wilting leaves or stunted growth. If necessary, provide additional water or shade as needed until they adjust to their new home in your garden.
How to Care for Marigolds
- Water — Marigolds are pretty drought-tolerant and too much water can actually harm their development. When watering, make sure to give the soil a good soak so that the water reaches down to the roots where it’s needed most. Then, allow the top layer of soil to dry out completely before watering again.
- Fertiliser — Marigolds are heavy feeders and will benefit from being fertilised every 2-3 weeks during the growing season. A balanced fertiliser like 10-10-10 or 20-20-20 is a good choice, or you can use an organic fertiliser such as compost tea.
- Deadhead spent blooms — To encourage continuous blooming, be sure to remove spent flowers as soon as they fade. Cut the stem back to just above where it emerges from the foliage.
Marigold Companion Planting
Marigolds make excellent companion plants because they release a compound called pyrethrin into the soil, which repels harmful pests like nematodes, whiteflies, and Mexican bean beetles.
Here are some of the best plants to pair with marigolds for companion planting.
Tomatoes and marigolds are a classic combination. The strong scent of marigolds helps deter pests like aphids, whiteflies, and even rabbits from getting near your tomatoes.
Like tomatoes, eggplants are susceptible to aphids and whiteflies.
Placing marigolds near eggplants will help keep these pesky insects at bay so your eggplants can thrive.
Marigolds also grow well with capsicums — both sweet capsicums and hot capsicums.
The pyrethrin in marigold flowers will help protect your bell pepper plants from aphids, whiteflies, and even rabbits.
Marigolds are commonly planted with potatoes because they are known to be effective at deterring pests like Colorado potato beetles.
These destructive pests can quickly decimate a potato crop, so having marigolds around can help reduce the amount of damage they cause.
Dandelions are rich in nutrients, including nitrogen, potassium, and calcium, improving soil quality as it grows.
When grown alongside marigolds, dandelions can attract pollinators and also help to deter pests such as nematodes and slugs.
Fennel is known for attracting beneficial insects, such as ladybugs and lacewings, which help to control pests.
On the other hand, marigolds are known for deterring harmful nematodes.
As a result, planting these two flowers together can help to create a more balanced garden ecosystem.
Common Pests and Diseases Affecting Marigold Blooms
From rust to aphids, there are a number of problems that can plague your marigold plants.
Keep reading to learn more about some common marigold pests and diseases, as well as how to prevent them.
These small, winged insects suck the sap out of plants, causing marigolds to wilt and their leaves to yellow.
To get rid of aphids, try spraying your plants with water or rubbing alcohol. You can also attract aphid-eating ladybugs to your garden by planting dandelions or fennel.
Thrips are tiny, winged insects that feed on the leaves of marigolds, causing them to become discoloured and distorted.
To control thrips, keep your garden clean and free of debris.
You can also try spraying your plants with an insecticidal soap or neem oil solution (use the code LAWN10 for 10% off!).
Powdery mildew is another fungal disease that affects the leaves of marigolds, causing them to appear covered in a white powdery substance.
To prevent powdery mildew, space your plants well and water them at the base instead of from above.
You can also treat powdery mildew with a fungicide designed for use on ornamentals.
Rust is a fungal disease that affects a variety of plants, including marigolds. It appears as orange or brown spots on the upper surfaces of leaves.
To prevent rust from taking hold in your garden, be sure to remove any affected leaves as soon as you see them.
You should also avoid watering your plants from overhead, as this can help spread the spores.
Leaf spot is a fungal disease that affects the leaves of marigolds, causing them to develop brown or black spots.
To prevent leaf spot, space your plants well and water them early in the day so that the foliage has time to dry before nightfall.
Growing Marigolds FAQs
Benefits of Marigolds
The benefits of marigolds are many and varied.
In the garden, the scent of marigolds is dual purpose — it can attract bees and butterflies, and also repel insects, such as mosquitoes, moths and flies.
Their roots also help to aerate the soil and their leaves add nutrients that help other plants grow healthily.
Are Marigolds Perennials?
Most gardeners will say yes and no. But the truth is marigolds are annuals — they complete their life cycle in just one growing season.
This means they don’t need to be babied over the winter, and they will self-seed (meaning they’ll come back year after year with very little help from you).
Their self-seeding characteristic makes them look like perennials.
Are Marigolds Annuals?
Yes. Marigolds are annuals in most growing zones.
This means that they will die off at the end of the growing season and will need to be replanted the following spring.
I’m Feeling Marigolden, And So Can You
Now that you know everything there is to know about how to grow marigolds in Australia, it’s time to get out there and give it a try.
And if you run into any problems along the way, our professional gardeners can help keep your flowers blooming throughout the year.