Should you disinfect old flower pots before reusing?

Yes, especially if they held diseased plants. Use a 1:9 bleach to water solution for 10 minutes.

Can you put flower pots in the dishwasher?

Plastic and ceramic pots can go in the dishwasher. Terracotta should be hand cleaned -- the dishwasher heat can crack it.

The white residue is mineral salts. Soak in vinegar solution for 30 minutes and scrub with a brush.

Yes. Empty, clean, and dry pots before storing. Bring terracotta indoors or to a sheltered area to prevent freeze damage.

Outdoor

Outdoor surfaces take a beating from weather, dirt, and use. Here's how to clean your flower pots and keep them looking great.

1
Empty the pot
Remove old soil, plants, and roots. Knock loose dirt off the sides.
2
Soak in vinegar solution
Fill a bucket or sink with 1 part vinegar to 4 parts warm water. Submerge the pot and let soak for 30 minutes to dissolve mineral deposits.
3
Scrub with a brush
Scrub the inside and outside of the pot with a stiff brush to remove dirt, salt deposits, and algae.
4
Disinfect with bleach if needed
If the pot held diseased plants, soak in a solution of 1 part bleach to 9 parts water for 10 minutes to kill pathogens.
5
Rinse and dry
Rinse thoroughly with clean water until all bleach or vinegar is gone. Air dry completely before storing or replanting.

TIPAlways disinfect pots that held diseased plants before reusing -- pathogens survive in pot residue.
TIPSoak terracotta pots in water for 30 minutes before planting to prevent them from wicking moisture from new plants.
TIPStack clean dry pots in a sheltered area for winter to prevent freezing damage.

XReusing pots from diseased plants without disinfecting, which spreads disease to new plants.
XLeaving terracotta pots outside in freezing temperatures with soil inside, which causes them to crack.
XSkipping the rinse after using bleach, which can harm new plants.

Soak in a vinegar solution (1:4 with water) for 30 minutes, then scrub with a brush to remove the white salt buildup.