How to measure your sunflower

A fair, fun contest depends on everyone measuring the same way. Here's how to get an accurate height for the boards — and how to measure a giant safely.

What to measure

Measure the whole plant, straight up, from soil level to its highest point — the top of the main flower head once it's blooming, or the tip of the tallest growing point before then. Measure the true vertical height, not along a leaning stem.

Measuring shorter plants

Hold a tape measure or a metre ruler vertically next to the stem, base resting at the soil, and read off the height at the top of the plant. Keep the tape straight and upright.

Measuring tall ones

• The cane method: push a tall garden cane into the ground right beside the stem, mark the cane level with the top of the plant, then lay the cane down and measure to the mark.
• The two-person method: one person holds the tape at the base, the other reads it at the top (use a step-ladder for the very tall ones).
• The reference method: stand next to it — if you're 1.7 m and the sunflower reaches a hand-span above your head, you can estimate from there. Better still, hold a cane of known length up against it.

When to measure

You can post a height at any stage and update it through the season to track growth and build your time-lapse. For your best leaderboard position, measure once the plant has reached its full height — usually around flowering, when it stops climbing. Try to measure at the same time of day for consistency.

Units & honesty

Enter centimetres or inches — Sunometer converts either way. And please measure honestly: the boards are only fun if the numbers are real. A neat trick for credibility is to include your tape or a marked cane in the photo.