Reviewing
Cosmos 'Sensation' Seeds26 Aug 2026
Can't go wrong with Cosmos
Lovely packet of seeds, bought one for me and one as gift :)
Gareth
Giant Sunflower Seeds
Helianthus Annuus 'Giant Single'
Giant Sunflowers, the tallest Helianthus Annuus variety, are perfect for growing in pots or gardens. These majestic yellow sunflowers can soar over 2m, symbolising growth and positivity. Ideal for sunflower races, our sunflower seeds to plant promise robust sunflower growth and a garden alive with bees, butterflies, and birds. Plant sunflower seeds that transform into golden, giant blooms, bringing life and joy to your space.
Approx 20 seeds
Only 4 left
- Needs Extra Care
- Sun Loving
- Cut Flowers
- Pollinator-Friendly
Only 4 left
Giant Sunflower Seeds – Quick Growing Guide
Start your giant sunflower seeds outdoors after the last frost in a sunny garden bed or container, where they will thrive in full sun. These tall sunflowers prefer well-drained soil and plenty of light to reach their majestic height throughout the summer months from June to September.
How to Sow, Grow and Harvest Giant Sunflower Seeds
- Sow:Mar–Jun
- Germination:7–14 days
- Grow:Full sun, well-drained soil, support tall stems
- Water:Moderate, keep soil moist but not waterlogged
- Harvest:Late summer, when seed heads turn brown
- Best for:Beds, borders, cut flowers
Our giant sunflower seeds produce some of the tallest Helianthus Annuus varieties, reaching over 2 metres. Ideal for gardens and containers, these sunflowers attract bees, butterflies and birds, making your outdoor space vibrant and full of life. Their sunny yellow blooms symbolise positivity and growth, perfect for summer displays and sunflower races.
Delivered within 2–3 working days. On its own, this packet ships letterbox delivery at £2.25. Fits through a standard letterbox, so no one needs to be home.
Delivery is priced on the size of your whole order, so adding more may move it into the next band:
- Letterbox delivery — small orders
- £2.25
- Standard delivery — most orders
- £4.50
- Standard delivery (multiple parcels) — large orders
- £7.50
- Free delivery (orders £60 and over)
- Free
Gifting. We can include a handwritten note — add your message at checkout.
More info in our FAQs, or get in touch if something hasn’t arrived.
Grow in Your Garden
Grow Majestic Giant Sunflowers with Herboo
Calendar
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SowFlowers / Harvest
How to Grow
Start your giant sunflower seeds outdoors after the last frost in a sunny garden bed or container, where they will thrive in full sun. These tall sunflowers prefer well-drained soil and plenty of light to reach their majestic height throughout the summer months from June to September.
Sowing
Sow the seeds in pots or trays filled with damp seed compost, lightly covering them to encourage germination. Keep the containers in a warm, sunny spot during the sowing period from March to June to ensure good sprouting conditions.
Growing
Once seedlings have emerged, thin them out to allow enough space for each plant to grow to its full size, ideally in a 40 cm pot or well-spaced garden bed. Providing sufficient room supports the impressive spread and height typical of Helianthus Annuus 'Giant Single'.
Plant care
Keep the soil consistently moist but not waterlogged throughout the growing season. As these sunflowers grow tall, occasional support may be necessary to prevent bending. Deadhead spent flowers to encourage continued blooming and maintain the plant’s vigour during the summer months.
About Giant Sunflower
A classic, fast-growing annual that produces towering stems topped with huge golden blooms. Giant Single sunflowers are easy to grow from seed, thrive in full sun, and make a dramatic statement in borders, allotments, or wildlife-friendly gardens. Excellent for pollinators and perfect for growing with children.
- Needs Extra Care
- Sun Loving
- Cut Flowers
- Pollinator-Friendly
Eventual height & spread
0.6m
3m
History of Giant Sunflower
Sunflowers represent loyalty and adoration, inspired by the myth of Clytie and Apollo. Their bright blooms follow the sun, symbolising happiness and making them a thoughtful summer gift.
| Other Names | Comb flower, golden, golden flower of Peru, St Bartholomew's star |
|---|---|
| Pet/Baby Safe | Pet + Baby Safe |
FAQs
They can reach over 2 metres tall.
Yes, they thrive in large pots with full sun. It is suited to beds, borders and cut flowers.
Watering: moderate, keep soil moist but not waterlogged. It is an annual, completing its whole life in one season, so sow again the following year.
Sow from March to June. Seedlings usually appear in 7–14 days.
Yes — this is a straightforward packet to give, and what makes it work as a gift is mostly timing. Sowing runs March to June, so a packet given inside that window can go straight in, and one given outside it keeps perfectly well until the season comes round.
There are approximately 20 seeds in the packet. On effort it looks after itself, which matters if you are giving it to someone new to growing. It suits beds, borders and cut flowers, so it works for a small space as well as a garden.
Reviews
No reviews yet for Giant Sunflower Seeds. If you have grown it, yours would be the first.
Elsewhere in the range
Recent reviews of other Herboo seeds. These are not ratings of Giant Sunflower Seeds.
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Good card gifts
Bought a couple of these as card gifts for friends and they loved them
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Good tips
Liked how you gave tips on how best to sow. nicely done
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