Yes plants are alive. And they do "experience" the environment. and in many ways, respond to it. But that does make them sentient.
BTW, in case you didn't hear, the authors of the Secret Lives of Plants falsified their data, their experiments have not been replicated, and the authors themselves have admitted that they made that stuff up.
Sentience can be a bit of a bit confusing but I still think Bentham stated it succinctly 300 years ago when he said, ""The question is not, Can they reason? nor, Can they talk? but, Can they suffer?"
But it can get complicated, confusing, and controversial.
There is the argument based on admitting imperfect knowledge and therefore erring on the side of caution. We can't know what an oyster is experiencing so we don't eat them. And I suppose you can extend that argument to an asparagus plant. So an apple that has fallen to the ground is ok. and so are grains that are annuals and are already dead.
However we all cause harm to living things just by living, so maybe it's not Do No Harm. but just do the least amount. And I suppose it's up to you to decide what is the least amount.
I don't know what clones have to do with this.