Mr Gardener wrote: |>A couple days ago I made the mistake of putting my tomato seedlings out |>on a windowsill for direct sunlight, and a few hours later I discovered |>they were all withered. (We've had a lot of sunlight here lately in |>Portland, Oregon.) |>
|>I immediately removed them, and enclosed them in a humidity-containing |>package (it used to be a doughnut package but I filled it up halfway |>with potting soil), and hid it away. |>
|>The next day, 10% of the seedlings began to perk up again. |>
|>If I buy a photometer, how much light should tomato seedlings be exposed |>to? |>
|>Is the real problem loss of water instead of too much sunlight? | |You probably shocked your plants with the sudden bright light.
Well, yes, probably.
|Seedlings need time to acclimate to bright sun.
Are there any breeds of tomato that are less shockable than Beefsteak or Roma?
|Try them for just an hour a day, doubling the time each day. And make |sure they are getting enough water and food.
I was hoping that the tomatoes would thrive on potting soil and high humidity.
|I can't imagine plants getting too much sun, as long as they are |gradually acclimated. Considering your location, you have plenty of time |to start over again, a few times.
Yes.
|Sow them in your humidity container and as soon as the very first bit of |green appears, get them out of the humidity and into the light. Your |bright window should be fine if done this way. Flourescent tubes an inch |above the plants would do as well.
I have theory that Cool White fluorescent lights will work just as fine as Grow Lights.
|No acclimatation needed. The humidity beyond this point is asking for |fungus / damping off / weakening.
Argh! I was hoping the terrarium would be self-sufficient, and I could just seal them off from the outside world.
|conditions. |And you don't need a photo meter, unless you are a very serious |photographer.
If I knew the amount of light that was appropriate, I could computerize the setup.