Sweet peas can go in as soon as the ground can be worked providing it is not wet. :) I have only ever started larkspur in the house.

Ginny

You can sow larkspurs in the autumn or early spring. Mine self-seed. Mine are up everywhere!
Sweet peas need the cold spring temps followed by warm, sunny spring weather to germinate. They don't like high temps or dry weather.
~Annie

Sweet pea plants are fairly hardy but they need warmer temps to germinate. I start mine in a glazed porch in early February. They are now being hardened off outside the back door and will be planted out in a few days. This way they get off to an earlier start in the garden than by waiting for sufficiently warm soil outside.

Mindy,
in your zone, you can go ahead and sow the Larkspur and poppy seeds now. Wait until April to sow the Sweet peas.
Or if you have a very sunny room, you can start them indoors and set them out in mid-to-late April, depending upon how warm your soil is by then.
I use the peat pellets in Dixie cups. Put the pellets into the small Dixie cups (like bathroom size), add warm water. When they soak up the water, place a sw. pea seed into the moist pellet (or two seeds), and set in a sunny Southern window. Works good.
When it's time to set them out, harden them off for a few days in a warm location out of wind and direct sun shine. Then all you need to do is set the entire cupped-plant into a hole and pull the soil over level with the top. The paper cups will rot away quickly and you don't get transplant shock. This also protects the seedlings from Cut Worms.
You can grow any kind of annual or perennials like that, including veggies.
~Annie