Easy to make a mini greenhouse.
Required: 5 liter PET bottle, cable ties or stapler, some rods.
The seeds can be planted immediately to their final places.
There are no transplant shock.
Protect the seedlings from frost, rain, strong wind, drying, animals and perhaps the slugs.
In the picture are 10x3 pcs tomato seeds.
In a other row are 5x3 same tomato seeds for compare controll, without bottle.
I will report the result.