I've planted the Benary's Giant Dahlia Blue Point in Salmon Rose and White this year (Geo Seed Co.) with pretty good luck. Some were started inside under lights about 3-4 weeks before setting out and some were just seeded in the ground well after the last fost date. I gave them more space between plants this year and put up some netting to give them some support. I think that helped make nicer flowers for cutting although some are larger than others. Watered a lot in the beginning (and weeded) then let them pretty much go as we have had adequate rain. The bed they are in had a bunch compost added a couple of years ago, no other amendments. Too much nitrogen will encourage green but not blooms so be careful not to use fertilizer with a high first number (the N). They get full sun. They probably aren't as huge as the pampered greenhouse grown flowers but most are quite large with long stems. When I cut them I try to note where side shoots are and leave those for later flowers. I'll attach a couple of pics. Another variety that has produced some really large flowers for me are the Super Cactus zinnias also from Geo. Also Senora. Cresto Cream didn't do much. My biggest problem is the darn Japanese beetles that like to chew on them.

I also grow smaller varieies like thumbelina and zaharas which are also pretty in flower beds and nice in smaller vases but I, too, enjoy the jumbo ones.

pics-Benary Salmon Rose and Senora in vase, B.White,

and the big orange one in the pic of boot vase

going to the nursing home is Super Cactus with a Benary white next to it..

Severe, what is your garden like? Sunny? Soil conditions? Enough water? Also, did you get a name on those zinnias you just found? If so you could try finding seed for those. I would think that anything you buy potted like that is going to be pumped full of fertilizers. I'm too lazy of a gardener to fertilize consistently, but I do try to pay attention to my soil, adding shredded leaves twice a year and either compost or manure every other year (or when I think of it lol. Like I said, lazy!)

mnzinnia your plants look nice and healthy. I'm intrigued by how close you plant them. What spacing do you use when planting? I was just thinking the other day that I need to plant my annuals (zinnias in particular) closer. I tend to plant my perennials too close together and my annuals too far apart lol!

Thanks,
:)
Dee