Sometimes they dry out, curl up, and die. More control of the humidity and temperature is required when the seedlings are starting.
This indoor greenhouse (or green pup-tent) gives newly potted plants a better chance of survival.
I have also used it to revive young plants that are struggling or in shock.
The picture shows a 3in & 4in clay pot. Adjust the frame size to fit your needs.
Step 1: What You Need
The round sticks are 12in bamboo shish-ka-bob skewers, about .15in diameter. The dollar store has a big bag for...a dollar. I find many uses for these tough little sticks. Trim to length by rolling under a utility knife (add a utility knife to picture #2). For sides longer than 12in, glue two sticks lengthwise.
The square pieces are 3/8in hardwood. You can find these at Home Depot or Lowes. A four foot length is less than two dollars. Look in the 'hobby wood' section or in the moulding bins.
A plastic drop cloth will be cut to fit the frame.
Step 2: The Frame
Attach a small c-clamp as shown to keep the wood from splitting. A vise with smooth jaws would work fine, too.
Make the through holes a little small, then sand the skewer ends for a tight slip fit.
A close-up of one corner. Repeat as needed.
I didn't use any glue because I want to break the frame down when it's not being used.