Agardener has 27 pansies and 36 daisies he ants an equal number of each type of flower in each row what is the greatest possible number of pansies in each row

There are 27 pansies.
The possible rows that will contain equal numbers of pansies are
1 row, 27 pansies in the row, or
3 rows, 9 pansies per row, or
9 rows, 3 pansies per row.

There are 36 daisies.
The possible rows that will contain equal numbers of daisies are
1 row, 36 daisies in the row,
2 rows, 18 daisies per row, or
3 rows, 12 daisies per row, or
4 rows, 9 daisies per row, or
6 rows, 6  daisies per row, or
9 rows, 4  daisies per row, or
12 rows, 3 daisies per row, or
18  rows, 2 daisies per row.

The only common row combination is 3 rows, with 9 pansies and 12 daisies per row.

 9 pansies in each row.