HOW TO START SEEDS INDOORS VIDEO!
I am in the process of building a seed starting room/greenhouse under a part of my house that was left unfinished when we bought it. I had hoped to have it done in time to start my seeds there this spring as it is all set up with grow lights and heat pads that can be placed under trays, but we have had a ridiculously cold winter and I have been waiting for a day with temperatures above 45 degrees for 24 hours so that I can caulk my new windows. Usually we will have a spell of weather in late January or early February where we get a couple of days in the 50's or 60's, but this has been about the coldest Winter I can remember. Last winter I covered the walls with 6 mil plastic sheets to get a jump on Spring, but the plastic ripped all to shreds and so I am in the process of going with a more permanent solution. I bought some 4' x 5' double pain windows from the local Habitat for Humanity re-sale shop for $10 each. They allow light for the entire east side of the room. I also purchased a nice used double hung window ($10) to go next to the door so that if the room gets too hot in late Spring I can open a window for ventilation. This space has exterior walls from my house on two sides and a finished roof overhead so there is convective heat coming to it from 3 sides. If I can finish the new exterior walls it ought never freeze even without a heater. It is not ideal with only east sunlight, but supplemented with grow lights I can get a 2-3 month head start on Spring and even without grow lights I would get a good 30 day jump on Spring.
Enough about my works in progress and back to starting seeds. I am going to utilize a west facing window in our bathroom for our seed growing. I like to use a combination of Perlite and peat moss. This is usually the composition of pre-mixed seed starting soil mixtures that you can also use. The Perlite provides a little bit of air for the developing roots without drying them out, and the acidity of the peat moss inhibits root rot problems. If you choose to go with a compost soil you create, it really should be baked in the oven at 180 degrees for about 30 minutes to kill all the harmful pathogens. This can be stinky work, so do it on a day when you can open windows, if possible, and not when company is coming over. If you are a beginner, just buy some Perlite and peat moss. This will get you going.
If you are re-using pots, it is a good idea to soak the old ones in a bath of water and chlorine, dunking them several times to make sure all surfaces are clean. I used to think this stuff was ridiculous, but having lost a lot of seeds to various fungal deaths (root rot), I can say from experience, it is worth it to either start with new pots and soil or sterilize the re-used products. When I first saw a greenhouse operation that looked like an operating room, I thought, "how silly, seeds don't have a sterile environment in nature." What I have learned is that when growing seeds indoors we don't give plants the natural sterilants of direct sunshine and wind drying that give them a better shot in nature. Also, in nature, most seeds don't survive and I want to have all mine survive. Another trick to preventing fungal problems with delicate seeds is to provide a fan in the room (not directly on the plants) to circulate the air. This will make the seedlings stronger and help dry out the soil surface where fungal problems usually occur. If you have ever had a healthy seed germinate then suddenly fall over and die, that is probably a fungal problem.
2"x2" pots
I usually fill the pots almost all the way to the top, allowing for a dusting of soil over the seeds after they are placed. I then place two seeds per pot, believing that if one is more vigorous I can either pinch off the weaker plant or separate them at a later date when they are more durable to handle. Some people like to grow tens, if not hundreds, in trays and then after germination transplant them into individual pots. This is very tedious, so if you have the space, I think the two per pot method works for most gardeners. Some well organized people will soak their larger seeds overnight before planting. I never know when I will be planting seeds that much in advance and it only makes your seeds germinate a couple of days earlier so I don't think it is necessary.
I usually fill the pots almost all the way to the top, allowing for a dusting of soil over the seeds after they are placed. I then place two seeds per pot, believing that if one is more vigorous I can either pinch off the weaker plant or separate them at a later date when they are more durable to handle. Some people like to grow tens, if not hundreds, in trays and then after germination transplant them into individual pots. This is very tedious, so if you have the space, I think the two per pot method works for most gardeners. Some well organized people will soak their larger seeds overnight before planting. I never know when I will be planting seeds that much in advance and it only makes your seeds germinate a couple of days earlier so I don't think it is necessary.