Planting a prairie

I'm nursing my trays of seedling prairie plants, trying to get them through the summer heat until I can plant them out in September. I will then fill in with seeds of native grasses and forbs. When I started the project I knew that it was going to take at least a full year to establish the bed and get the weeds under good control. I hoped to get a good start by planting seeds in trays and overwintering them since many need cold to germinate and spend most of their first year growing a root system. I have some good sized plants blooming from the first winter and trays of very insignificant looking seedlings from this past winter. I'll plant them out but on the whole, I think I invested a lot more time and effort than the result justified. I learned some things along the way but if I had it to do over, would probably just wait until the bed was ready and sow seeds directly.

Some problems I encountered:
My temporary cold frames were constructed from half inch PVC pipe covered with plastic sheeting. The hoops had a rather flattened profile that let snow and water collect and collapse the whole thing. More than once I was out in the sleet cleaning them off.

Then I left the covers on too long and I think it got too hot. Many seedlings fried and died.

The cats thought the cold frames made a cozy place for a springtime nap. Having large hairy beasts lying on them didn't do the seedlings any good either.