i have to write a ballad. The 1st and 3rd lines need to be in iambic tetrameter and 2nd and 4th in iambic trimeter. is this right?

Today I told my friend about
The dream I had one night.
“This red rose grew alone
In a small lot without sunlight.”

The first and second lines are right, but not the third and fourth. Remember the rhythm you're after.

da DUM da DUM da DUM da DUM
da DUM da DUM da DUM
da DUM da DUM da DUM da DUM
da DUM da DUM da DUM