Can I use water-butt water on seedlings?

Use fresh tap water for seed trays, containers of newly sown seed and young seedlings. RHS guidance says stored water from water butts may contain pathogens that can affect seedling growth.

Separate the most sensitive uses

Stored rainwater is valuable for established plants, but propagation is a more vulnerable stage. Keep a clean watering can for fresh water used on seeds and seedlings, and avoid dipping it into a communal tank where soil or plant debris can enter.

Seeds and seedlings also need even moisture. Water gently so the compost is moistened without washing seed out of position or leaving containers waterlogged. Check small modules frequently because their limited volume dries faster than an open bed.

Maintain the collection system

Fit a lid or secure cover where appropriate, keep gutters clear and stop debris entering the butt. Follow site safety rules, especially where children visit. A water butt is storage, not a guarantee that the collected water suits every use.