. How does the houseplant symbolize Lena’s dream?

The plant becomes a metaphor for Mama's family. Ar the family breaks apart, so does the plant. Mama tries to nurture and bring the plant back to life, she does the same with her family. Even though the plant is dying, she tends to it every day in the hope that she might bring it to life,

"Lord if this little old plant don't get more sun than its been getting, it ain't never going to see spring again".

The same can be said for her family. They need love, light, and nurturing.