Indoor seedlings--taking outside for more light--temp question

[NewcoopNewpoop]

I have some iceberg and romaine seedlings I started indoors. They are an inch tall now.
I take them outside to get better light when the temps are up. My question is how low is too low to put them out for light while I wait for my last date of frost?

 

[21hens-incharge]

Maybe you can use garden cloches. Old milk jugs or 2 litre soda bottles work well as they have a lid that can be removed to prevent overheating. When is your last frost date?

https://www.amazon.com/s?k=garden+cloches+for+plants&adgrpid=1340305243817305&hvadid=83769400657233&hvbmt=be&hvdev=t&hvlocphy=96060&hvnetw=o&hvqmt=e&hvtargid=kwd-83769433959933:loc-190&hydadcr=23635_13532313&mcid=ee2e2440a147384fa71e3145e107f056&tag=mh0b-20&ref=pd_sl_2xutqlfitp_e

 

[NewcoopNewpoop]

Its either the 1st or 15th of may. But im thinking about making a frame with plastic to get them out sooner.

 

[21hens-incharge]

I have similar last frost date here.

If you built a "low tunnel" with pvc arches and plastic cover you may even be able to plant them now. I used pvc and hdx plastic from home depot on mine.

Looks like amazon has a lot of options too.

https://www.amazon.com/s?k=low+tunn...49c14e28b59&tag=mh0b-20&ref=pd_sl_6arzhkn1t_e

 

[NewcoopNewpoop]

Does the type of plastic matter? I have thinner plastic here at home that was sold as dropcloth plastic.