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SUNFLOWER CHALLENGE 2023: WEEK 6 - Hardening off

Are your sunflowers looking the same or are they at different stages?

In the beginning, Danny encouraged you and the team to start your sunflowers off inside for safety and warmth. But, now it's time for the big world. The nights can still get chilly, so we do this in stages called hardening off

Do you know what you need to look out for when hardening off? Danny Clarke and Fran Lawton will show you the top things to remember when hardening of your sunflower to prepare them for transplanting (popping them in the ground outside permanently.)

Why is hardening off important?

The nights can still be cold in the UK at this time of year, so we want to make sure our sunflowers don't get too cold as it can be fatal. There are some signs to look out for on your sunflower leaves if they're too cold (or even sun damage!)

  • - Blistering around the edges of the leaves
  • - Burning around the edges of the leaves

Luckily sunflowers are hardy plants. You can prune off any damage, and keep bringing the sunflower inside during the nights until the flower is stronger. It will be stronger when it's taller and has more leaves. Then it will be safe to be transplanted.

Examples of burnt leaves and blistered sunflower leaves


How will you and the team remember to bring your sunflower out in the morning and back in at night? Here are some ideas:- Unlocking or locking the cat flap

  • - Brushing your teeth morning and night
  • - Bringing the dog out for a walk (grabbing the lead!)
  • - Setting an alarm
  • - Opening and closing the curtains
  • - Get the team leader to remind you!



We’re always keen to see you with your sunflower, so send us a snap of you hardening off your sunflower to be featured on our website.

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After a week of hardening off, you and your team's sunflowers should be ready for the permanent move. So, next week we’ll show you how to transplant them.

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