Well I have been gardening for many years and there are a couple of things you should know.

First a window sill is not ideal for germinating seeds. Most seeds do not need light to germinate. They need a bit of heat--not too much mind you. The window sill is the coolest place in your house. Move your trays to a warmer place. If you can find a place with a bit of heat so much the better. It used to be that on top of the fridge was a good place but with the new energy efficient fridges it gives off no heat. Even if you can't find a place like that move them to the warmest spot in your house.

Next--If you put your plants outside with the clear plastic domes they will fry. It is unbelievable how much the sun will heat up a small enclosed space. Domes are for keeping the moisture in so seeds will germinate. Remove the domes as soon as your plants germinate and put them aside for next year.

Plants need air circulation or the wet soil will encourage mold. It is not ideal but put them back in the window sill and outside in a protected place on nice days--no covers. You do have to harden them off when first putting them outside. They have to get used to the UV rays. So start them in the shade and gradually over a week give them more and more sun.

I wish you luck

I'm listening! We recently purchased a huge neglected property, and I just purchased seeds. It's warm enough here to sow outside, but I have a small greenhouse, and would love to start some colorful annuals for path borders.

The sun definitely will fry anything inside a dome, so I am hoping to learn how to work this mini greenhouse to avoid that.

I wish you luck with all your seeds!

Suzi

Great info from dowlinggram above. Most importantly the part about leaving on a dome outside.

I would strongly suggest you first read the FAQs provided here on how to grow from seed and the FAQ on how to harden off plants before moving them outside. Lots of folks before you have tried to grow seedlings using only window light and reported on the poor results of leggy weak plants, slow or no germination and cooked seedlings. But many prefer to do their own experiments and sometimes that is the best way to learn what works and what doesn't.

Dave

Here is a link that might be useful: Growing from Seed FAQs

desertdance Get yourself a minimum-maximum thermometer. You set it and it tells you just how warm and how cold it got since it was set. A thermometer is also good for telling you when the vents on your greenhouse should be open. Place it in a shaded part of the greenhouse--like under the bench so you get a true reading.

In my greenhouse I find that the vents have to be opened daily. It does not take long for the sun to heat it up. Even on a cloudy day it can get very hot if the vents aren't open. On a sunny day my vents and door are usually open. On excessively hot days I take my plants outside in the shade. This not only gives them relief from the heat but hardens them off for planting--gets them used to the UV rays.

Stick to growing plants that like your growing conditions. In your case sun loving with low water needs

The best teacher is trial and error so give it a shot and I hope this helps and your plants do well

I have seedlings as of today. I moved the trays outside this morning in an area where they will get a lot of light.

The trays are on the deck with no domes and in an area where they will get some sun, but not all day sun.

There was no frost on the ground this morning.

I would like to clarify I had the trays in the kitchen.

I never said they were on a window sill. They were in fact on the floor in a corner near a register. The draft kept the air moving and mold from growing.

Thanks for the advice about the domes. I will be sure to leave them off.

Thanks!

I would like to clarify I had the trays in the kitchen

"Windowsill" is just a term used to distinguish between trying to grow using only natural light vs. providing supplemental lighting.

The distinction is between any sort of window light - light just from outside sources vs. using supplemental indoor light.

Even greenhouses use supplemental lighting this time of year.

Dave

I live in Melbourne , Australia , I decided to grow some seeds purchased from ebay , I bought some cuban mahogany , ylang ylang and poinciana . All tropicals , its getting into mid Autumn here and temperatures are ranging from about 10 degrees celcius to about 24 . ( too low for germination ) So out from the garage I brought my "ecko hostess carousel " food warmer . After soaking the seeds in small medicine containers with water, I wore these so as to stay warm with my body heat for 24 hours. Then put them into small trays with potting mix , into the hostess carousel . Due to the fact there is no timer or thermostat , well I think I might have cooked them , the temps must have got up around 50 degrees centigrade . Anyway I just had a look , the potting mix is erupting ! I can see a poinciana pushing its way up through the soil. It took 3 days to germinate . Is that normal ? these poinciana's are very tough cookies .