It all depends on the size of your operation. We are part-time growers and sellers at only 1 Farmers Market. In addition we sell seedlings out of our greenhouse. We find that a packet of seeds is adequate for us. Sometimes we got a couple of a particular variety. Of course we grow many varieties of particular plant: Zinnias, Celosia, Snaps, Asters, Tomatoes, Peppers, etc. We end up with more than 80 tomato varieties, 10 peppers, 5 eggplants, 8 Zinnias, and so on. So I guess it's a lot of seeds that way, but we don't buy hundreds of one particular variety, just a pack.

Maybe large growers can help

Gardengirl, My zinnias go in at a nine-inch spacing and that comes out to 134 plants per hundred foot row. Last year I had 4 rows which put me at about 520 plants. This year I ordered 1000 Benary's mix seeds so I'll have plenty for direct seeding after I get my transplants in.

The only thing that works for me is to actually decide how many plants I'm going to want, then look at the spacing and do a little math to get a number of row-feet. Then I add some to make up for the seeds that didn't germinate and add some more to make sure I don't run out. That's about the best I can do in the advice department.

I grow a lot of sunflowers, and this year I ordered 6000 seeds. Other things I get by the 1000, 500, 200, or 100 packets, depending on how I feel about being able to grow and sell them.

Planning this stuff is not easy, but it helps when you have a few years of knowing what grew well and sold well for you.

ThinMan

Thank you for your responses. Thinman, thanks for the great advice on planting zinnias. Do you plant everything by hand or do you have a planter?

Other than sunflowers I don't do a lot of direct seeding, but I do have an Earthway seeder that works pretty well for some things. I've learned to use it for sunflowers and I've read somewhere recently that it can be used for zinnias so I'm going to give that a try this year. To get a good head start on our short season, I start a lot of my plants early and set them out in June.

TM

Gardengirl
As Tommyk advised, it depends upon the size of your operation and I may add, how long your season is, + how your flowers are marketed. I've got a 12 month growing season but only sell 8-9. In that period as an example, I'll start sowing Zinnias in March and then every month till August, to fill 2 x 100' beds with 4 rows. So that's 1,072 zinnia plants every month. This is probably more than I need but when you factor in loss of plants due to gophers, mole damage, fire ants, etc etc etc, I'm covered. Always grow more than you'll need.
Each year you will determine how much of something needs to be grown, it's trial and error. You learn what plants are extremely productive and what's a one off cut (sunflowers) and you tweak your seed orders every year appropriately.
Cheers - Kim BFFF

Thanks for the info Kim. Last year I didn't plant enough and lost out on a lot of sales....so I want to do better this year with making sure I plant enough. It's nice to hear what experienced flower farmers do.