We’re looking for the tallest sunflower in the country! If you’ve got a green thumb and a sunny spot, you could win a £250 Thompson & Morgan voucher. Sow your seeds as soon as they arrive and support them as they grow. You have until noon on the 5th October 2026 to reach for the sky!
To help get you started, we’re giving away 300 free packets of ‘High Hopes’ Sunflower Seeds. Be quick – this is first come, first served, with one packet per address. Complete the form below to claim yours…
Free sunflower seeds – limited giveaway
How to take part
It’s simple to get involved:
- Sow your ‘High Hopes’ Sunflower Seeds (other varieties are not eligible)
- Follow our expert growing tips below
- Join our Sunflower Grow-A-Long on Instagram.
- Share your progress – Post photos or videos on Instagram, Facebook or TikTok using #TMTallestSunflower.
Prizes
- 1st prize: £250 Thompson & Morgan voucher for the tallest sunflower
- Runners-up: Two x £50 Thompson & Morgan vouchers for the 2nd and 3rd tallest sunflowers
How the competition will be judged
The winner will be the grower of the biggest ‘High Hopes’ sunflower by noon on 5 October 2026. Proof will be required in the form of:
- A genuine photo and/or short video of your sunflower (sent to blog@thompson-morgan.com)
- Height in cm (with tape measure visible)
- Confirmation that Thompson & Morgan ‘High Hopes’ sunflower seeds were used
10 tips for growing sunflowers
Image: Sunflower ‘High Hopes’ from Thompson and Morgan
- If you’re starting sunflower seeds indoors, sow them now in small pots and keep them indoors. Bury the seeds about 1–2cm deep.
- As soon as the risk of frost has passed, you can direct sow your seeds outdoors. Pop them into 1–2cm deep holes in well-prepared soil.
- Once they germinate, choose the strongest seedlings to grow on.
- Harden off indoor-raised seedlings for 7–10 days before planting outside.
- Plant them in a sunny, sheltered spot. If possible, grow your sunflowers against a solid, south-facing wall for additional support.
- Dig plenty of organic matter into the soil to support strong root growth.
- Keep a look out for slugs when plants are young.
- If you’ve sown your seeds in groups, thin the seedlings early to leave the strongest plant in each spot. This avoids overcrowding and competition.
- As they grow, stake your sunflowers and tie them in to keep tall stems supported.
- Water regularly and feed with a high-potassium fertiliser, such as tomato feed, to encourage strong growth.
Tallest Sunflower Growing Competition – Terms & Conditions
- Promoter
This competition is organised by Thompson & Morgan (the “Promoter”), part of the Branded Garden Products Ltd group.
Trading address: Thompson & Morgan, Poplar Lane, Ipswich, Suffolk, IP8 3BU. - Eligibility
- The competition is open to residents of mainland United Kingdom only.
- Entrants must be aged 18 or over, or have permission from a parent or guardian.
- Employees of the Promoter, their immediate families, agents, or anyone professionally connected with the competition are not eligible to enter.
- Entry Requirements
- All sunflowers must be grown from ‘High Hopes’ sunflower seeds supplied by Thompson & Morgan.
- The Promoter reserves the right to request proof of seeds used.
- Entries must be submitted via email to blog@thompson-morgan.com.
- Each entry must include:
- Full name and contact details
- Measurement of the sunflower (height in cm)
- Clear photographic evidence, including a tape measure
- Incomplete, late, or invalid entries will not be accepted.
- Competition Period
- All entries must be received by 12 noon on 5 October 2026.
- Entries received after this time will not be considered.
- Judging & Verification
- The winner will be determined by the tallest sunflower (by height).
- In the event of a tie, judges may consider additional measurements, visual appearance, and flower head size.
- The winning sunflower must be available for inspection during the week commencing 5 October 2026.
- The Promoter reserves the right to verify entries in person and disqualify any entry deemed inaccurate, misleading, or fraudulent.
- Prizes
- First prize: £250 Thompson & Morgan voucher.
- Two runners-up prizes: £50 Thompson & Morgan vouchers each (awarded for the second and third tallest sunflowers).
- Prizes are non-transferable, non-refundable, and no cash alternative will be offered.
- Winner Notification
- Winners will be contacted using the details provided within 7 days of the closing date.
- If a winner does not respond within 7 days, the Promoter reserves the right to select an alternative winner.
- Publicity
- By entering, participants agree that the Promoter may use their name and photographs for promotional and marketing purposes without additional compensation.
- Data Protection
- Personal data supplied when entering this competition will only be used for administration purposes and in accordance with the Promoter’s privacy policy.
- For more information, please refer to the privacy policy.
- Liability
- The Promoter accepts no responsibility for entries that are lost, delayed, incomplete, or corrupted.
- The Promoter shall not be liable for any loss, damage, or injury suffered as a result of entering the competition or accepting a prize, except where liability cannot be excluded by law.
- General
- The Promoter reserves the right to amend, suspend, or cancel the competition where necessary due to circumstances beyond its control.
- The Promoter’s decision is final and no correspondence will be entered into.
- This competition is governed by English law and subject to the exclusive jurisdiction of the courts of England and Wales.
The Thompson & Morgan horticultural team produces a wealth of content around gardening and food production. Since the first seed catalogue was published in 1855, Thompson & Morgan has grown to become one of the UK’s largest Mail Order Seed and Plant companies. Through the publication of our catalogues and the operation of our award-winning website, Thompson & Morgan is able to provide home gardeners with the very best quality products money can buy.