The word GARDEN has 6 letters.
Therefore, all the ways of permuting the letters of GARDEN are: 6!
Now, the questions wants the vowels to appear in alphabetical order, this means that in all the words, A must appear before E.
There are 2! ways of permuting A and E out of which we just want 1, so the final answer is: 6!⋅12!=7202=360