Answer:
There are 17 total plants of tomatoes, lets count case per case assuming that the order does not matter (because we don't have any information about if the plants are indistinguishable or anything like that)
1) 17 rows with one plant each.
2) 15 rows with one plant, one row with two
3) 13 rows with one plant, 2 with two plants
4) 11 rows with one plant, 3 with two plants
5) 9 rows with one plant, 4 with two plants
6) 7 rows with one plant, 5 with two plants
7) 5 rows with one plant, 6 rows with two plants
8) 3 rows with one plant, 7 rows with two plants
9) 1 row with one plant, 8 rows with two plants.
So, if the order of these rows does not matter, there are 9 ways in which the plants can be ordered.