Squirrels are very difficult animals to discourage. Here are some bulletins with ideas:

https://www.purdue.edu/fnr/extension/video-stop-animals-digging-in-flower-pots/

https://yardandgarden.extension.iastate.edu/faq/how-can-i-keep-squirrels-digging-newly-planted-tulip-bulbs

https://extensionpubs.unl.edu/publication/ec1783/2012/pdf/view/ec1783-2012.pdf

For containers when planting, put chicken wire over newly planted seeds, bulbs, and let plants grow through them. For already planted containers, use wire mesh hardware cloth cut in donut shapes to encircle the plants? ( see first bulletin, above).

If container can be hung such that the squirrel cannot jump into the pot, that can help.

Actually placing squirrel food, like field corn on the cob, staked firmly down 50 feet or more away from the containers may lure them away.

If you have bird feeders, temporarily removing them so the squirrels are not attracted to your yard, may get them to move to a neighboring feeder. Or, install recommended bird feeder squirrel guards.

Most effective among all the repellents is capsaicin( hot red pepper) but it must be reapplied often- after leaves are rinsed by rain or you irrigating the plants. Repellents are the least effective of all controls.

There are plants less attractive to squirrels. These include hot peppers, garlic, onions and onion family like garlic chives( caution these are aggressive in the garden) and alliums. Lily of the Valley( caution these are aggressive in the garden)geraniums, galanthus, and some bulbs like hyacinth and daffodil.

Nothing is totally effective. Try moving your containers where there is more human activity, or farther away from safe hiding places like shrubs and trees.