The speaker is a flower, and the person addressed is the gardener. Deadheading means snipping off spent blooms so a plant stays healthy and keeps flowering. The speaker uses this gardening act as a way to talk about care in a relationship.
The tone is hurt and questioning. The poem opens with "Why did you pick me?", which sounds less like curiosity than disappointment. The speaker feels they gave their partner steady, attentive care, and got none back. They even said so, "No matter how many times / i told you," yet nothing changed. The final lines show what this neglect costs: without being tended, the speaker cannot "maintain / my appearance / and blossom."
The mood is quiet, sad and a little accusing. Because the speaker is picked, like a flower, they seem to have had little say, and now they are left to wilt. The poem suggests that love needs effort from both sides, not just one.