Are plants completely

independent from other

organisms?

no

Explanation:

Nothing is ever completly indepenet from other organisms because everything relies on evreything else such as a plant relies on bees and other insects and animals to pollinate them they also rely on animals to die and fertalize the soil

yes, some plants are fern gametophyte and sporophyte generations are completely independent, in some types of plants one generation lives on or in the other and depends on it for nutrition.