A dirty feeder is more than unpleasant — mouldy or fermented nectar can genuinely make hummingbirds sick. The good news is that cleaning takes only a few minutes if you do it regularly.
Clean it every time you refill
Empty and clean your feeder every time you change the nectar — every 3–5 days in mild weather, and every 1–2 days in hot weather, when sugar water spoils fast. Getting into this routine is the single best thing you can do for the birds' health.
The simple cleaning method
Take the feeder apart and rinse all the pieces in hot water, using a bottle brush for the reservoir and small brushes or cotton buds for the feeding ports. For most cleans, hot water and a good scrub are enough. If you use any soap, rinse very thoroughly, as leftover residue can taint the nectar.
Getting rid of mould
If you spot black mould, soak the parts in a solution of one part white vinegar to four parts water for an hour or so, then scrub and rinse well. A few grains of uncooked rice swirled with water can help scour narrow ports. Let everything drain, then refill with fresh nectar. Avoid harsh bleach.