I'm impressed with Johnny's solar mulch
I just put it on 6 days ago in preparation for planting okra. Here's some soil temps. I measured at the 6" depth this evening.
Outdoors: 60 F
Inside my high tunnel (row cover and plastic): 66 F
Inside my high tunnel in a bed covered with solar mulch: 73 F
The funny thing is, we haven't seen much of the sun for days now...rain, rain and more rain in the forecast.