How to grow sunflowers in Perth

Growing sunflowers in Perth

Sunflowers are a great way to add colour to your garden, and they’re easy to grow and care for. Sunflowers are typically yellow, although you can also grow red, orange and striped ones as well. They range in size from dwarfs that grow less than a metre high, to giants that can grow over 3.5m tall and produce flowers up to 50cm wide. Part of the magic of sunflowers is that the flowers will turn to face the sun as they grow. Growing sunflowers in Perth, Western Australia is very easy due to our sunny skies as sunflowers need at least 6-8 hours of sun a day which isn’t a problem in Perth.

Driving by a paddock of sunflowers in bloom is a breathtaking sight. Sunflowers follow the path of the sun, in fact the leaves do as well which is why they look so captivating as they move en masse. This phenomenon is called heliotropism.

Sunflowers are one of the fastest growing plants, able to reach two metres in around six months. They make a great food for poultry and other stock. Sunflowers are also nutritious source of edible seed and are commonly used to create cooking oil also.

Best climate for sunflowers:
Sunflowers are incredibly versatile an can be grown in all climate zones across Australia. If you live in cool or colder parts of Western Australia like the South-West, wait until the chance of last frost has passed before sowing seeds or planting seedlings. For most parts of Western Australia including Perth, you can plant sunflowers from spring to early summer.

Sunflower varieties:
Sunflower seeds have three main outlets – for their high quality oil and protein, for birdseed, and interestingly for the confectionary trade.

Most of the open-pollinated varieties of sunflowers which are suitable for oil production are of Russian origin.

Recent breeding has concentrated on developing sunflowers that have seeds with a high oil content. Plants that are better suited to gardens are also being produced, including small growing varieties and some with double flowers.

List of sunflower varieties:
Sunflower Sunbird – Tall, drought resistanct variety which make a great support for climbing beans.
Sunflower Teddy Bear – Teddy Bear is cute and compact, with spectacular fluffy yellow flowers like a bear’s fur! Small enough to grow in pots. Often produces multiple flowers per stem to make a bushy shrub. Great for small gardens.
Sunflower Infinity – Sporting multiple flowers per plant in a lovely golden yellow colour with dark centres these short robust plants are easy to grow and create a beautiful picture. Because they are short these are highly suitable for pots. Grows to approx 40cm high.
Sunflower Giant Russian – A majestic plant with enormous golden yellow flower heads. Great fun to grow with impressively quick results – ideal for children. A hardy annual, flowering the same year. Requires a sunny position.
Sunflower Golden Prominence F1 – Striking colour contrast and ideal height for cut flower. Quick maturing.
Sunflower Royal Velvet F1 (Helianthus annuus) – Unique ornamental sunflower. Large primary head flowers first. Small branching flowers follow. Long flowering period.
Sunflower Solar Flash F1 – Multiple heads with bi-colour petals on compact plants. Pollen free, great cut flower.
Sunflower Princess F1 – A tall hardy easy to grow variety with bright yellow petals and dark centres. Produces long lasting cut flowers. Pollen free. Best staked to support the heavy flower heads.
Sunflower Supernova F1 – A robust tall height variety with large single flowers. Very easy to grow, quick to flower and pollen free!
Sunflower Lemon Striker F1 – A robust medium height variety with multiple lemon yellow blooms. Very easy to grow and pollen free!
Sunflower Lemon Bling F1 – A compact robust variety with multiple lemon yellow blooms. Very easy to grow and pollen free!

Dwarf sunflower varieties:
Sunflower Dwarf Sunsation – Bright, cheerful, robust and always a favourite with children, this dwarf variety will grow well in the garden or in pots. Dwarf Sunsation has compact, golden-yellow petals and is very quick to flower. An annual flowering in the same year.
Sunflower Dwarf Microsun – A short and robust growing dwarf variety suitable for pots or novelty border plantings in the garden. Large primary flower head with numerous side branching secondary flowers. Bright yellow petals surrounding a dark centre. Pollen free.
Sunflower Dwarf Eos – Extra compact plants to 25cm (10”) .Very quick to flower. Produces multiple flower heads. Pollen free bright yellow blooms.

How to plant sunflowers?

  1. Choose an area in the garden that receives between 6-8 hours of sun daily and ensure there is protection from strong winds.
  2. Enrich the soil by adding Dynamic Lifter Soil Improver & Plant Fertiliser and fork in well. If the soil is hard to dig, add liquid gypsum to help break it up before planting sunflowers.  Ideal soil conditions lie between a pH level of 6.0 and 7.5, however, they’re pretty hardy so will grow in most soils with some care.
  3. Sow seeds and cover with soil. Plant your seeds 50-60cm apart. Gently press down on the soil and water well.  Ensure the seeds remain moist during germination.  It can take 8-14 days for seeds to germinate.
  4. When seedlings are 5 cm tall, spread a 5-6 cm layer of organic mulch, such sugar cane or pea straw around the base of the plants.
  5. Once flower buds form, feed with liquid plant food.

Growing sunflowers in pots:
If you intend to grow sunflowers in a pot, make sure you’re starting with a dwarf variety. Dwarf sunflowers are more compact, grow up to around 50cm in height and are very quick to flower. They will also thrive in a smaller size pot.

How to harvest sunflower seeds?
Once the sunflower heads are mature, they form seeds in the centre of the head. To save the seed for next season’s planting or to harvest the seeds for cooking, allow the head to dry out on the plant. Cover the heads with paper bags or netting to keep the birds away. Once the flowers begin to yellow and die, cut the heads and store them upside down in a dry spot. When ready, the seeds should loosen in the head. Tap on the back of the head of the sunflower and allow the seeds to collect in a bucket or tray below.

Storing sunflower seeds:
If you are saving seed, store them in an air-tight container, in a cool dry spot, out of direct sunlight.

Sunflower diseases and common problems:
Snails and slugs love to chew on the foliage of young sunflower seedlings. Protect plants by scattering Snail & Slug Pellets around small seedlings and nearby plants. Repeat in 7-10 days, if necessary. Sap-sucking insects like whitefly, thrips and aphids also love the foliage. They’re often hiding in new growth or under the foliage, so be sure to check plants regularly and treat early as possible.

Sunflowers are also susceptible to a variety of fungal diseases, including rust and powdery mildew. Spray at first sign of the disease with a suitable garden fungicide.

As your sunflowers grow, they will become top heavy and need staking. This will also protect them in high winds or in the rain. Sunflowers need a deep, regular watering. This will encourage good root growth and a large, heathy bloom. The ideal time to water is in the morning, as root rot can set in over cold nights. Sunflowers can also benefit from a liquid fertiliser every two to three weeks, which will help boost their height.

Check out our other how to grow in Perth guides:

Leave a comment