It's pretty much the same as winter time.

Use plenty of soil- at least 3". I use extra vent holes in the top to allow heat to escape, and keep them in shade. Dappled shade would probably be OK. Just make sure they don't dry out. And unless the seeds are very fresh, you might want to avoid things that need cold strat. Sometimes seeds fresh from the plant don't require cold to overcome their dormancy.

Karen

I summer sowed dianthus and Shasta daisy in recycled recycled milk jugs after transplanting the original WS seedlings. I just crossed off the seed name & date from WS and wrote the SS name & date. As Karen recommends, I poked a half dozen holes near the top of the jug to let warm air escape and I'm keeping the jugs in dappled shade. They get a little late afternoon sun. I check them every day and set any that feel dry in a saucer of water. The seeds sprouted very fast--some after only 4-5 days! I decided to sow more seeds once I saw the first few sprouts and have so far done columbine, gaillardia/blanket flower, helenium, blue flax & 'Irish Eyes' rudbeckia. Haven't taken any pictures yet but will try to shoot a few today.

I keep notes on my winter sowing that include lists of which seeds need cold strat and which don't. I'm SS from the list of seeds that don't require a cold period to germinate. I wanted sweet William 'Sooty' in bloom again next year and since it's a biennial, knew I had to grow the plants this year in order to have flowers next spring. The seedpods had opened so I figured the seeds were ripe and judging by what appears to be 100% germination I see in the jug, I'm guessing they were ready to be sowed!

I summer sowed the same as I winter sowed--the only difference is the vent holes in the top of the jugs.

Thank you both for your info on SS. I'm finding it interesting that seed that would normally require cold stratification may germinate if planted soon after harvesting, and germinate well without the cold treatment.

I have a few dwarf Lupine seeds from my own plant, and we seem to have a hard time keeping these plants going more than a year or two in our area. I may go ahead and SS a few of the newly harvested seed just to see what happens. I need to put in some Arizona Red Gaillardia seeds too since I lost the plant over the winter. I had put the plant in in the fall but it never re-appeared this spring. My Arizona Sun, that I've had for at least three years has faithfully returned. I really liked the AR and am sorry it didn't make it.

I'll post about the SS'd lupines if I have success. Thanks again,
Linda