I grew Cascadia twice last year - late winter/early spring and then again in late summer/fall. I'm in Middle GA - it's hot here. The first round were planted about a month before last frost and they came up in about two weeks - much better than others. They produced pretty well considering how quickly it got hot. I mulched heavily which helped. I don't think 48 days is realistic tho... more like 68 for me. I started planting small numbers again in late August hoping for a fall/winter crop. They would sprout, but wither from the heat. Finally ones planted in early October took. I got a small crop, but finally they were pretty much wiped out by hard freezes in late Dec. I will plant them again this spring - am tracking soil temps this year. :)

I'd keep the plastic on during the day and gather the sides up for air circulation...then overnight cover fully? The seeds probably need some moisture, but not a soaking wet? Get too wet and cold and they will damp off? Not sure. I started lettuce last year outside towards the end of April in zone 5. Found a packet of Mesclun Gormet Greens Mixture seeds (Ferry-Morse)...an assortment of kale...lettuces...endive...arugula. Last year I was eating lettuce like a rabbit...this year the rabbit goes to Paris on vacation. ;-)

I just soak my pea seeds and then drain and keep damp for 12-24 hours until I see the roots just starting. Then I sow the sprouted seed out in the garden as per usual. It seems to prevent rot if the weather turns cool and wet. I planted my first batch yesterday (Wednesday) morning, 3 varieties of snap peas: Cascadia, Sugar Daddy, and Sugar Snap.

UPDATE: I have collected the following varieties of blueberry, raspberries and strawberries: By Next summer (2018) and anytime after I would be happy to offer plants & rooted cuttings to others on trade. Strawberry: Albion, Ozark Beauty, Seascape, and Jewel, more on the way. Raspberry: Prelude, Nova, Encore, Polana, Joan J, Himbo Top, Black Hawk, Cumberland, and Dundee. Also more on the way. Blueberry: Patriot, Bluecrop, Elliot, Duke, Blueray, Chandler, Hardiblue, and Toro.