Adopt some sort of nearby insect in a mutualistic relationship.
[3] Being an explosive plant, you find no way to form such a relationship. The only thing you discover is that hitting a fly causes it to pop, but hey! That's still fun!
OK, BE OAK TREE THAT HAS ACORNS THAT WHEN EATEN BY SENTIENT BEINGS GRANT THEM GODHOOD AND TASTE EXTREMELY BITER TO NON-SENTIENTS.
[2] You're a birch. Birches don't even have acorns.
Evolve accounting-based leaves. As they grow, they will record the details of the area in a human-parsable form.
[4] Your leaves begin writing themselves into a human language about the debts of the nearby plants! [1] It's all in ancient mayan!
I am a mushroom! Act like a plant!
[3] You are a fungus, and the plants suspect that you're a mushroom. Why? You're too much of a fun guy!
Fungi! Get it? Okay, I'll go cry now.Evolve to grow pre-rolled blunts.
[1] The pre-rolled blunts require too much energy, and soon you are wilting.
Evolve to make cocaine
[6] You begin creating cocaine. A passing by human detects you and begins devouring you.
Grow bigger! Non-spicy peppers will still keep them away if they're a foot in diameter!
[1] The peppers change in size! They are now smaller than they were before! A passing by sheep takes a quick bite, and snaps off the top half of your plant.
Be a cactus.
Have intoxicating liquid stored inside me.
[5] You are now the first cactus in the species known as "Moonshine Desert". A sheep seems to want to hug you, and doesn't get the memo that the spikes hurt it. Muahaahah!