In Spanish, the "like" verb works as shown in these examples (present):
A mi me gustan = I like them.
A ti te gustan = You (singular) like them.
A vosotros os gustan = You (plural) like them.
So:
Ti = you
The personal pronoun that would correctly fit the sentence is "te".
Therefore:
A ti te gustan las plantas = You (singular) like the plants.
Hope it helped,
BioTeacher101