TL;DR
A bin smells because bacteria are living on the residue baked into its walls and floor, not because of what is in it today. Rinse it out, treat it with an enzyme cleaner and let that dwell, scrub with a long brush, rinse again, and dry it upside down in the sun -- the drying step is what stops the smell from returning within days.
Why bins smell even after they are emptied
The odor is a byproduct of bacteria breaking down organic residue, and residue is exactly what a bin accumulates.
Every bag that leaks, every liquid that pools in the bottom corner, and every splash on the wall leaves a film. That film is a food supply. Add warmth and the enclosed, humid environment inside a lidded bin and you have close to ideal conditions for bacterial growth.
Cleaning the bin removes the food. Drying it removes the moisture. Doing one without the other is why bins that get hosed out are smelling again by the following week. There is a fuller explanation of the mechanism in why outdoor trash bins smell and in what actually causes household odors.
Source: Waste handling and odor control practice
How do you clean a smelly trash can?
Empty it, rinse out loose debris, apply an enzyme cleaner and let it sit 15 to 30 minutes, scrub the walls and floor with a long-handled brush, rinse thoroughly, and stand the bin upside down to dry completely. Enzymes digest the residue that odor-masking sprays only cover.
The method, step by step
Time it right. Do this the day it is collected, when the bin is empty. Do it on a dry, sunny day if you can, because the drying step needs it.
Rinse the loose material out. Tip the bin, hose out debris, and pour the water somewhere it will soak into ground rather than run into a storm drain. Waste water carrying organic residue should not go into a storm system.
Apply an enzyme cleaner. This is the step that does the real work. Enzyme cleaners contain bacteria and enzymes that digest the organic residue itself rather than perfuming over it. Coat the walls, the floor, the lid, and the underside of the lid rim. Let it dwell 15 to 30 minutes -- enzymes work over time, not on contact. Choosing one is covered in what to look for in an enzyme cleaner.
Scrub with a long-handled brush. A deck brush or a dedicated bin brush reaches the bottom without you climbing in. Work the corners and the bottom seam, where residue collects and where a short brush never reaches. Do the lid separately, including the underside and the hinge area.
Rinse thoroughly. Any cleaner residue left behind is itself a film that attracts more soil.
Dry it upside down. Tip the bin on its side or fully inverted, propped so air moves through it, and give it several hours in the sun. Ultraviolet light helps, and a genuinely dry bin does not grow anything. This step is skipped more than any other and it is the one that determines how long the result lasts.
What to use, and what never to combine
Enzyme cleaner is the first choice for odor, because it removes the source.
Dish soap and hot water handles greasy film and is a good general option, ideally after the enzyme step rather than instead of it.
Baking soda is useful as a mild abrasive and for absorbing residual odor after drying -- sprinkle some in the empty dry bin.
Diluted chlorine bleach sanitizes, and it is reasonable on a bin that has held something genuinely foul, but it does not remove residue and the smell returns once the chlorine dissipates. Use it after cleaning, not instead of cleaning.
Never mix products. Do not combine bleach with an ammonia-based cleaner, with vinegar, or with any acidic cleaner. Bleach plus ammonia releases chloramine gas and bleach plus acid releases chlorine gas. Bins are a particular hazard here because people improvise -- some cleaner, some bleach, a splash of vinegar -- while leaning over the opening of a container that concentrates fumes. Use one product, rinse completely, then use another if you must.
Do not mix bleach with an enzyme cleaner either. Bleach kills the bacteria the enzyme product relies on, so the two simply cancel each other out.
Recycling bins have a different problem
They usually smell less, but they attract more insects.
The residue in a recycling bin is sugar -- soda, juice, beer, and sauce left in containers. Sugar residue draws wasps, ants, and fruit flies, and it dries into a sticky film that a rinse alone will not lift.
The fix is upstream. Rinse containers before they go in the bin, especially anything that held liquid. It takes seconds per item and it eliminates most of the problem. Check your local guidance, since some programs specifically ask for rinsed containers and some do not accept ones with food residue at all.
Keeping them clean between washes
Bag everything, and double-bag anything wet or high-odor.
Freeze the worst offenders. Meat trays, fish scraps, and bones can go in the freezer until collection day. This single habit removes most warm-weather bin odor.
Line the bottom. A layer of newspaper or a small amount of absorbent in the bottom of the bin catches leaks before they reach the plastic.
Sprinkle baking soda or a bin deodorizer in the dry bin after cleaning.
Keep the lid closed and the bin out of direct afternoon sun where you can. Heat accelerates everything.
Store bins on a hard surface rather than on grass or dirt, so the underside stays dry and you are not creating a damp habitat beneath them.
How often
Once a month in warm weather and once a quarter in cool weather works for most households. A bin that holds food waste, pet waste, or diapers wants more frequent attention. Pet waste specifically has its own outdoor considerations in cleaning an outdoor pet waste area, and general odor strategy is covered in odor removal.
FAQ
What is the best thing to clean a garbage can with?
An enzyme cleaner, because it digests the organic residue that odor-causing bacteria feed on rather than masking the smell. Dish soap and hot water is a good supporting step for greasy film. Bleach sanitizes but does not remove residue, so the odor returns once the chlorine dissipates.
How do I stop my trash can from smelling in summer?
Freeze high-odor waste like meat trays and fish scraps until collection day, double-bag anything wet, keep the lid closed, and store the bin out of direct afternoon sun. Clean it monthly with an enzyme cleaner and, crucially, dry it fully upside down afterward.
Can I use bleach in a trash can?
Diluted bleach is reasonable as a sanitizing step after the bin has been cleaned, but not as the cleaning itself, since it does not remove the residue causing the smell. Never combine it with ammonia, vinegar, any acid, or an enzyme cleaner, which it simply kills.
Why does my recycling bin attract wasps?
Sugar residue from soda, juice, beer, and sauce containers. It dries into a sticky film that a plain rinse does not lift, and it is a reliable insect attractant. Rinsing containers before they go into the bin removes most of the problem at the source.
Can I pressure wash my garbage bin?
Yes, with a wide tip at moderate distance. Avoid narrow tips at close range, which can gouge or thin plastic that has become brittle from sun exposure. Direct the wash water into ground or a sanitary drain rather than a storm drain, since it carries organic residue.
How often should trash bins be cleaned?
Monthly in warm weather and quarterly when it is cool suits most households. Bins that regularly hold food waste, pet waste, or diapers need more frequent cleaning. The day of collection, when the bin is empty and the forecast is dry, is the practical window.
Does baking soda actually help with bin odor?
It helps modestly, by absorbing residual odor and acting as a mild abrasive during scrubbing. It works best sprinkled into a bin that is already clean and dry. On its own, in a bin still coated with residue, it does very little, because the source is still there.
Where this is one task among many, recurring house cleaning services take the broader load.
Bin count, how long the residue has built up, and where the wash water can go all change what a proper cleaning takes, and some bins are past reviving. Every situation is different, so get a quote and we will talk through it.