I'm not certain, but think if it was an established plant will resprout given water & diluted fertilizer. Pelargonium are tender perennials and there are also hardy geraniums that endure cutting back to the main stem after bloom.

Do not give it full strength fertilizer or you may over do it. If you don't purchase fertilizer use what you have around to make a compost tea for it.

Seems silly, but used coffee grounds work fairly well to just put around the base of the plant. You can get them free at St*rbucks or ask a coffee drinker.

Likewise kitchen vegetable & fruit scraps put into a bucket & covered with water to set for a few days will be smelly, but nutrients will leach into the water & you can use that for watering OR dig a hole next to the plant & deposit the scraps into it & cover back up. No one will know you have banana peels feeding your plants.

I also use dried grass clippings as mulch that feeds the plants as it decomposes. Just be sure no herbicide was used on the lawn in the past.