Hey Devi,

Welcome to the forum! Always great to have new folk arrive!

I'm not in E TN, but I hate to see queries go unanswered...

I've grown annual sweet peas commercially, so my experience may or may not be helpful to you. I start them in a cold greenhouse, meaning it gets down to about 34 but doesn't freeze. As you may know, lathyrus loves cold, most soil. You just want to avoid lots of freeze-thaw cycles. Some folks soak seed before sowing, but I never have and haven't had any problems. I do, however, use inoculant, which, oddly, no one tells you to do with sweet peas. Like all other legumes, the rhizobia help the pea roots uptake nutrients. I sow into the final container if possible, as pea seedlings resent transplanting; if you're careful and bump them up before they get very big, transplanting is OK. I use ProMix BX and incorporate a charge of granular fertilizer, my favorite being Flower-Tone (97% organic and great for all herbaceous plants). Mice love to raid the pots for those big fat seeds, so if you have mice (and you may and not know it, particularly in a garage or basement) it's a good idea to put screen over the pot/flat until the peas are well up and growing. This is a hungry species. I topdress with Flower-tone when they're about 1 ft high, and again as they're setting buds. The peas should be blooming in May/June if you get them going now. They hate hot weather, so they basically fry by the end of June. England is their kind of climate, actually -- or the Pacific Northwest.

In terms of varieties, I've never grown the knee-hi types ('Snoopea' et al) so can't speak to those. I select for flower color, size and scent and have found performance is generally OK over a wide variety of colors and series. Spencers are good, and Floribundas, and I've had particularly good luck with a series called the Winter Series. I buy seed commercially, and I'm not sure what's available to the homeowner. I have grown a few varieties offered by Thompson & Morgan over the years, and a pink one called 'Rosemary Vesey' (IIRC the name right) did quite well. T & M's sweet pea seeds seem to offer no germination issues, unlike most everything else they sell.

Culturally, I give 'em full sun. Moving them into part shade about mid-May prolongs their life a bit. Early in life, though, they need high light or they get weak and stretchy. Bud set seems to be initiated by high light and increasing day length.

Never started them in mixed containers. It may work, but I'd be inclined to start the seed in a container and carefully transplant int into the mixed pot at about 6" tall. But then, my aim is always to produce marketable containers, so everything has to work very predictably for me.

Hope this helps.

Marty

Start them indoors and set out in March. They can take fairly hard frosts. I live in West Tennessee, and even as hot as it is here, the old-fashioned varieties will thrive until June. I've even had blossoms as late as August 1, but most are gone by the second week in June. None but the old fashioned varieties succeed for me.