Over many years with orchids, I have refined a 'humidity chamber' (orchid seeds cannot germinate on their own, so we do it in a sterile flask with a nutrient jell; the seedlings we get that way are tiny and need help to get established out of the flask).
In recent years I have also worked with Clivia miniata, importing seed from South Africa. By utilizing my humidity chambers, I have raised the germination rate from +/-70% to 95-98%. These chambers should also be useful for starting vegetables & annuals:
I buy clear Sterilite storage boxes with clear lid (available in 3 sizes, 27, 66 & 105 quart) from Walmart. Then:
Drill 7/8" holes abt 2.1/2" above the bottom for shelf carriers. Use a 'spade type' drill, and use only weight of drill to cut the hole (if you press, the wall cracks). For 105 qt size you need 3 shelf carriers, in the two smaller sizes 2 are enough.
Cut 1/2" PVC pipe to length (use pipe caps on ends to prevent the pipe from slipping back through the wall). Available at Home Depot.
Use either 'egg crate' (light diffusing panel for suspended ceilings), or a piece of a metal wire shelf, to cut a shelf to size. Available at Home Depot.
For use in a greenhouse, I also add a drain hole about 1.1/2" above the bottom. Not recommended for use in a house.
If your house is on cool side, place the humidity chamber on a seedling heat mat to raise the temperature a little.
If you have inadequate light, place it under 1 or 2 fluorescent plant lights.
Fill about 1" of water into the bottom, and sow your seeds. With this chamber, you will only need to water the seeds every couple of weeks.
Photo shows the 66 qt size with a shelf cut from 'egg crate'
Over many years with orchids, I have refined a 'humidity chamber' (orchid seeds cannot germinate on their own, so we do it in a sterile flask with a nutrient jell; the seedlings we get that way are tiny and need help to get established out of the flask).
In recent years I have also worked with Clivia miniata, importing seed from South Africa. By utilizing my humidity chambers, I have raised the germination rate from +/-70% to 95-98%. These chambers should also be useful for starting vegetables & annuals:
I buy clear Sterilite storage boxes with clear lid (available in 3 sizes, 27, 66 & 105 quart) from Walmart. Then:
Photo shows the 66 qt size with a shelf cut from 'egg crate'