A quick guide to giant sunflowers

Last Updated on September 13, 2024 by Suttons Horticultural Team

Sunflowers are easy to grow, a great favourite with children, and play an important part in helping to feed our wildlife. If you’re a fan, why not try your hand at growing some ‘giants’? Here at Suttons, we offer some terrific options for those who like their sunflowers a little on the enormous side. For advice on how to grow giant sunflowers, along with the best varieties to try, you’ve come to the right place. 

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What are giant sunflowers?

If ‘normal’ sunflowers are big then what constitutes a ‘giant’? In fact the term giant sunflower encompasses two dimensions – some are immensely tall with large heads, and others are of medium to tall stature but feature enormous flower heads that provide a veritable banquet of tasty sunflower seeds come the autumn.

If you’re wondering how giant sunflowers grow so big and tall, it’s because they’re bred to grow for longer than other varieties. Blooming later means they grow bigger and bigger, either gaining in altitude or developing enormous heads, or a combination of the two.

How to grow giant sunflowers

To grow giant sunflowers, sow them singly under glass into multipurpose compost from March-April and outdoors from April-June once all risk of frost has passed. Your flowers will appear between July and September. Sunflowers need lots of sunshine to thrive and a sheltered position helps to keep your top-heavy giants upright.

You want your sunflowers’ roots to go deep and find plenty of nutrients to help them grow so make sure you dig plenty of organic matter into the soil. Stake your flowers and tie them as they grow to keep them nice and straight. A cane will do to begin with, but be prepared to swap this out for something taller and more substantial. Giant sunflowers can reach heights well in excess of 4m and can easily come down in windy weather.

Keep a look out for slugs during the early stages – they love to feast on baby sunflowers. As your plants grow, keep them well watered and fed – tomato feed is fine. 

Which giant sunflower varieties are best?

If you’re looking for giant sunflowers, Suttons offers several excellent varieties:

• Sunflower ‘Giraffe’. The name gives the game away – this sunflower is a true giant. Developed by plant breeder Victoria Wakefield over a 30-year period during which she repeatedly selected and crossed the seeds of the tallest sunflowers, this beauty consistently reaches a staggering height of 5.2m (17ft) and above.
• Sunflower ‘Giant Yellow’. This beautiful daisy-like giant sunflower grows to a height of around 1.8 – 2.7m (6 – 9ft) and features big, big blooms. To keep your sunflower growing upwards, pinch out the side shoots and use them in summer salads – sunflowers are edible.
• Sunflower ‘Pike’s Peak’. Reaching a height of 4.6m (15ft), ‘Pike’s Peak’ isn’t quite as tall as ‘Giraffe’, but it does feature a good, thick stem making it more suitable for more exposed locations. This variety also features lovely big seeds which make a great snack for birds and humans alike.
• Sunflower ‘Titan’. Tall at 3.5m (12ft), and with flowerheads the size of dustbin lids (50cm or 20” across), this sunflower truly deserves to be called a giant. ‘Titan’ is easy to grow and a real hit with children. The flowers feature bright yellow petals and, as a pollen-free variety, it’s ideal for hayfever sufferers. 

Sunflowers are so much fun to grow and children and wildlife love them. Giant varieties add extra excitement and they’re great for wildlife too. To pick up expert tips on plants and flowers to attract birds to your garden, make sure you head over to our Growing Guides where you’ll find lots of excellent advice.

Lead image: Sunflower Seeds – Giraffe from Suttons/©Branded Garden Products