Overview
- A TikTok video by user Brittany (handle allegedlybrittany) showing side-by-side plants drew heavy attention on July 5–6, 2026 with roughly 145,000 likes and widespread UK media pickup.
- Coverage describes the horticultural mechanism as coffee grounds lowering soil pH, which increases soluble aluminium that some hydrangeas absorb to produce blue petals.
- The effect is limited to aluminium‑responsive varieties such as lacecap, bigleaf and mophead hydrangeas and will not turn oakleaf or smooth types like Annabelle blue.
- Commenters quoted by the outlets recommended simple methods—sprinkling grounds and watering or pouring cooled used coffee at the roots—but the reports treat these as user tips rather than tested advice.
- Outlets emphasised that the clip is an anecdotal demonstration rather than a controlled study, and it prompted many gardeners to ask how to try the method themselves.