Makshi, some plants and flowers make great combinations when planted together. I'd love to see red sunflowers looming over a sweep of the woolly-ish silvery Pearly Everlasting ( http://davesgarden.com/pf/go/457/index.html ) with another silvery plant that seems to glow from within like Miscanthus sinensis 'Morning Light'. Those 3 plants would all bloom together at the same time and really set each other off. (Here's the PlantFiles link for the grass: http://davesgarden.com/pf/go/54839/index.html - the pics don't capture the way its leaves held light in our garden - unforgettable, and who needs flowers when leaves can do That?)
Anyhoo, poppies make great companion plants in time, but not in space. Many of them have gone to seed by July, which is when it's wonderful to have a sunflower of some kind whose stalks you can pull over the patch of finished poppies - the sunflowers will bloom all along the stems in the leaf axils if you train the stems horizontally (and forward toward the front of the bed) - and their seed pods later on are part of the fun as birds use them for their playgrounds.
So, I would advise getting those poppies into the ground at least 4 weeks before your last spring frost date (either by direct sowing and/or by "hunk of seedling" wintersowing method) and then after that last spring frost, plant those sunflowers behind the poppy patch but close enough so you can pull those stems over.
Or - if you do plant the poppies and sunflowers at the same time, how about planting the poppies in a sweep in front of the sunflowers, but then replace them with the a white-flowered sage when they go crispy brown in July? There's an annual sage that in bud, gives the effect of a woolly-ish white, which stays all summer because it's constantly making new growth: Salvia farinacea 'Strata')? That species of sage has been successfully wintersown in your zone ( http://www.wintersown.org/wseo1/WS_Database_Z5.html ) and it's in PlantFiles here: http://davesgarden.com/pf/go/2870/index.html . A great picture of that effect is here: http://seeds.thompson-morgan.com/us/en/product/2032/1 )
The color scheme I'm reaching for pairs crimson with white flowers and silvery leaves. For another red plant in this association, a red morning glory like Scarlet O'Hara would be fun. One thing that makes the use of color like this so efffective is the variety of shapes in the flowers and leaves and textures that could be grouped together with red sunflowers.
PS - "hunk of seedling" (hos) method - http://www.wintersown.org/wseo1/Life_of_a_Poppy_Bed.html
And then there's the way white cleome captures light in late afternoon...fringed white, fragrant flowers of the gourd Lagenaria sicceraria (comes in various shapes like swan and trumpet) - a grove of red sunflowers between those two in late summer might be satisfying, too...
CLOSED: Variations On A Color Swap
Ohhh I am so anxious to get mine.I hope the starry nights swap seeds all arrive soon so they can be sent out.
Igot mine today, Yippee! Thanks everyone. Thanks X for the seeds and doing this neat swap. Iam enjoying it tremendously. Cool sunflowers blue. Ihaven't seen any Scarlet Milkwewd before. I may have to contact all of you for help on these. Thanks again all.
I got mine. Thanks X and thank everyone for a fun swap.