How To Grow Sunflower in Australia

Quick Guide: Growing Sunflowers

  • Optimal Growing Temperatures: Between 10°C and 30°C.
  • Ready to Harvest: 10-11 weeks after planting.
  • Space Between Plants: Plant 20-45 cm apart.
  • Companion Plants: Cucumbers, Melons, Squash
  • Non-Companion Plants: None
  • Plant Type: Seed.

When to Plant Sunflowers in Australia

Australia Map


Best planting months for Sunflowers in the Tropical regions are March to September. This includes areas like Cairns, Darwin, and Broome.

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For the Subtropical region, Sunflowers can be planted from January to April and July to December. Cities in the Subtropical region include Brisbane, Central Coast, and Sydney.

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Sunflowers can be planted from March to September in the Temperate regions of Australia. Cities in the Temperate region include Melbourne, Adelaide, Geelong, and Perth.

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For the Cool region, Sunflowers can be planted from September to December. Cities in the Cool region include alpine regions of Victoria and Tasmania.

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Best planting months for Sunflowers in the Arid region are January to March and August to December.

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Preparing for Sunflower Planting

Before diving into the exciting process of planting sunflowers, it's crucial to make the necessary preparations. This ensures that your sunflower seeds have the best chance of thriving and producing beautiful blooms. In this section, I will cover three important steps: choosing the right variety, selecting the ideal location, and preparing the soil.

Choosing the Right Variety

When it comes to sunflowers, there are numerous varieties to choose from. Each variety has its own unique characteristics, such as height, flower size, and colour. Consider factors such as the available space in your garden, the desired aesthetic, and the purpose of planting sunflowers (e.g., decorative or for harvesting seeds).

Here are a few popular sunflower varieties to consider:



Flower Size


Dwarf Sunflowers

1-2 feet



Teddy Bear Sunflowers

2-3 feet



Giant Sunflowers

8-12 feet



Take your time to explore the different varieties available and choose the one that suits your preferences. For more information on growing specific vegetables and herbs in Australia, check out our detailed articles on how to grow silverbeet, how to grow rhubarb, and how to grow parsley.

Selecting the Ideal Location

Sunflowers thrive in full sun, so it's important to choose a location in your garden that receives at least 6-8 hours of direct sunlight per day. Look for an area that is free from shade caused by tall trees or buildings.

It's also essential to consider the wind patterns in your area. Sunflowers have tall stalks, and strong winds can cause them to bend or topple over. To provide support, you may want to consider planting sunflowers near a fence or wall.

Preparing the Soil

Sunflowers require well-draining soil that is rich in organic matter. Start by removing any weeds or debris from the planting area. Loosen the soil to a depth of about 12 inches using a garden fork or tiller.

To improve the soil's fertility and drainage, incorporate compost or well-rotted manure. This helps to provide the necessary nutrients for healthy sunflower growth. Avoid using fresh manure, as it can be too strong and may burn the plants.

By choosing the right variety, selecting an ideal location, and preparing the soil, you are setting the stage for successful sunflower planting. In the next section, we will explore the process of planting sunflower seeds, including the optimal time to plant and proper techniques for watering and fertilising.

Planting Sunflower Seeds

Growing sunflowers from seeds is an exciting and rewarding experience. In this section, I will guide you through the process of planting sunflower seeds, including when to plant, how to plant, and proper watering and fertilising techniques.

When to Plant Sunflower Seeds

Sunflowers thrive in warm weather, making spring and early summer the ideal time for planting in Australia. The soil temperature should be around 15-30°C for successful germination. It's important to avoid planting seeds when the soil is still cold or when the risk of frost is high. For specific planting dates in your region, consult your local gardening resources or visit websites that provide regional gardening advice.

How to Plant Sunflower Seeds

Planting sunflower seeds is relatively straightforward. Here's a step-by-step guide to help you get started:

  1. Prepare the soil: Choose a location that receives full sun and has well-draining soil. Remove any weeds or debris and loosen the soil using a garden fork or tiller. Incorporate organic matter, such as compost, to improve soil fertility and drainage.
  2. Spacing: Sunflowers require adequate space to grow and spread their roots. Leave a distance of 30-60 cm between each seed or seedling, depending on the variety.
  3. Planting depth: Dig a small hole approximately 2-3 cm deep. Place a sunflower seed in the hole and cover it with soil. If you're planting multiple seeds, space them accordingly and cover them with soil.
  4. Watering: After planting, gently water the soil to provide moisture for germination. Be careful not to overwater, as excessive moisture can lead to seed rot. Keep the soil consistently moist but not waterlogged until the seedlings emerge.

Remember to consult the seed packet or the specific instructions provided by the seed supplier for any additional planting recommendations or variety-specific guidelines.

Watering and Fertilizing

Proper watering and fertilising are essential for healthy sunflower growth. Here are some tips to help you provide the right amount of water and nutrients:

  • Watering: Sunflowers have deep taproots, so it's important to water deeply and infrequently. Give your sunflowers a thorough watering once a week, ensuring that the soil is moist to a depth of at least 15 cm. Adjust the watering frequency based on weather conditions, increasing it during hot and dry periods. Avoid overwatering, as it can cause root rot and other issues.
  • Fertilising: Sunflowers are generally low-maintenance plants and do not require excessive fertilising. Before planting, incorporate well-rotted compost or organic matter into the soil to provide a nutrient-rich foundation. Once the seedlings emerge, you can apply a balanced organic fertiliser according to the manufacturer's instructions. Avoid over-fertilizing, as it can lead to excessive foliage growth and reduced flower production.

By following these guidelines, you can ensure that your sunflower seeds have the best chance of germinating and developing into healthy, vibrant plants. Stay tuned for the next section, where we'll explore the care and maintenance required to keep your sunflowers flourishing.

Caring for Sunflower Plants

To ensure healthy and vibrant sunflowers in Australia, proper care is essential. This section will cover important aspects of sunflower care, including sunlight and temperature requirements, proper watering techniques, and dealing with pests and diseases.

Sunlight and Temperature Requirements

Sunflowers thrive in abundant sunlight, making it crucial to choose a location that receives full sun exposure. Aim for at least six to eight hours of direct sunlight each day. Sunflowers are resilient and can tolerate a wide range of temperatures, but they prefer warm conditions. In Australia, it's best to plant sunflowers during spring or early summer when the soil has warmed up.

To ensure optimal growth, it's important to assess the sunlight and temperature conditions in your specific region. 

Proper Watering Techniques

Sunflowers have moderate water needs and require regular watering, especially during dry periods. It's important to strike a balance between providing enough moisture and avoiding overwatering, which can lead to root rot.

Water your sunflowers deeply, aiming to saturate the soil to a depth of around six inches. Watering in the morning or early evening is ideal, as this allows the plants to absorb the moisture before the heat of the day. Be mindful of the weather conditions and adjust your watering schedule accordingly. During periods of heavy rain, it may be necessary to scale back watering to prevent waterlogged soil.

To determine if your sunflowers need watering, you can check the soil moisture by inserting your finger into the ground. If the top inch of soil feels dry, it's time to water. Remember to water at the base of the plant to avoid wetting the leaves, which can promote fungal diseases. 

Dealing with Pests and Diseases

While sunflowers are generally resilient, they can still fall victim to various pests and diseases. Common pests that may pose a threat to your sunflowers include aphids, caterpillars, and snails. Regularly inspect the plants for any signs of infestation, such as distorted leaves or visible insects. If necessary, use organic pest control methods to manage the pests and protect your sunflowers.

Sunflowers are also susceptible to fungal diseases, such as powdery mildew and rust. To minimise the risk of these diseases, it's important to provide adequate air circulation by spacing the plants appropriately. Avoid overhead watering, as this can create a damp environment conducive to fungal growth. If signs of disease appear, promptly remove and dispose of the affected parts to prevent further spread.

By following these care tips, you can ensure that your sunflowers receive the attention they need to flourish. With proper sunlight, watering, and pest management, you'll be rewarded with a stunning display of sunflower beauty in your Australian garden.

Watching Sunflowers Flourish

As I nurtured my sunflower plants, I couldn't help but marvel at the growth and development of these beautiful flowers. Watching them flourish brought me immense joy and satisfaction. In this section, I will share some insights into the signs of growth and development, as well as tips for supporting tall sunflower stalks and harvesting sunflower seeds.

Signs of Growth and Development

As sunflowers grow, they go through several stages of development. Here are some key signs to look out for:

  1. Germination: After planting the seeds, you'll notice small seedlings emerging from the soil within 7 to 10 days. These delicate shoots will eventually develop into sturdy stems.
  2. Leaf Formation: The first set of leaves, known as cotyledons, will appear shortly after germination. These initial leaves are followed by the growth of true leaves, which have a distinct sunflower shape.
  3. Stem Growth: As the plants mature, the stems will elongate rapidly. Sunflowers are known for their impressive height, with some varieties reaching up to 12 feet or more. It's important to provide support to prevent the tall stalks from bending or toppling over.
  4. Bud Formation: As the plants continue to grow, you'll notice the formation of flower buds at the top of each stem. These buds will gradually develop into the iconic sunflower heads.
  5. Flower Blooming: With time, the sunflower heads will open up, revealing the vibrant yellow petals and the characteristic dark centre known as the disc florets. The flowers will face the sun, following its path throughout the day.

Supporting Tall Sunflower Stalks

Given their height, sunflower stalks may require support to prevent them from bending or breaking. Here are some tips for providing the necessary support:

  • Staking: Use bamboo stakes or other sturdy supports to prop up the sunflower stalks. Drive the stakes into the ground near the base of the plant, being careful not to damage the roots. Gently tie the stalks to the stakes with soft twine or garden clips, allowing them room to grow while providing stability.
  • Wind Protection: Sunflowers are susceptible to wind damage, especially when they grow tall. Consider planting them near a fence, wall, or other structures that can provide some protection against strong gusts.

Harvesting Sunflower Seeds

One of the most rewarding aspects of growing sunflowers is the opportunity to harvest the seeds. Follow these steps to collect the seeds once the flowers have fully matured:

  1. Observation: Monitor the sunflower heads closely as they begin to mature. The petals will start to wilt and fall off, and the disc florets in the centre will turn brown.
  2. Drying: Allow the sunflower heads to remain on the stalk until the back of the flower head turns yellow, and the seeds become plump. At this stage, the seeds are ready for harvesting.
  3. Harvesting: Cut the sunflower heads from the stalk, leaving a few inches of stem attached. Place the heads in a well-ventilated area, such as a paper bag or a mesh drying rack, to allow them to dry completely.
  4. Seed Extraction: Once the sunflower heads are dry, gently rub the seeds with your fingers or use a fork to remove them from the flower head. Separate the seeds from any remaining plant debris.
  5. Storage: Store the sunflower seeds in a dry, airtight container. They can be used for future planting or enjoyed as a nutritious snack.

Watching sunflowers flourish from seed to blooming flower is a truly rewarding experience. By understanding the signs of growth and development, providing support to tall stalks, and harvesting the seeds at the right time, you can fully appreciate the beauty and abundance of these magnificent flowers.

If you want to grow more plants and herbs in Australia, you can perfectly cultivate them with out A-Z Growing Guides.
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